WATERTIGHT COMPOSITE STRAIGHT WALL POST-TENSIONED CONCRETE TANK STRUCTURE AND METHODS FOR MAKING OR USING SAME

Abstract

The subject invention pertains to composite straight wall liquid storage tanks held in persistent compression to provide superior watertightness for the life of the tank, including ACI American Concrete Institute 350 code-compliant liquid-containing composite straight wall structures with an integral full-height galvanized steel shell diaphragm fully encased in continuous shotcrete. The provided tapered composite straight wall can incorporate epoxy-bonded diaphragm sheet joints at the floor, wall, L-shaped corner posts, and T-shaped bisecting wall junction plates to support watertight connections. The external envelope and, optionally, one or more internal or bisecting walls of the structure can be provided in persistent compression by compressive post-tensioning.

Claims

1. A tensioning system providing structural support, watertight sealing, and post-tensioning for a straight-wall concrete tank, the system comprising: a corner post comprising: a first plate comprising a first bearing surface defining a first direction and an opposite first tensioning surface, a second plate comprising a second bearing surface defining a second direction and an opposite second tensioning surface, a corner formed where the first plate is fixedly attached to the second plate, a first tab connector, fixedly attached to and extending from the first plate, configured to support a first diaphragm seal with a diaphragm sheet that is oriented substantially in the first direction, and a second tab connector fixedly attached to and extending from the second plate, configured to support a second diaphragm seal with a diaphragm sheet that is oriented substantially in the second direction; the corner post receiving a first persistent tensile load in the first direction and a second persistent tensile load in the second direction; the corner post providing structural support for a first persistent compressive load in the first direction and a second persistent compressive load in the second direction; and the corner post providing a persistent watertight connection between the first tab connector and the second tab connector.

2. The system according to claim 1, wherein the corner post is a first corner post, the system comprising a first multiplicity of tensioning strands configured and adapted to carry the first persistent tensile load in the first direction between the first corner post and a second corner post.

3. The system according to claim 2, comprising: a first multiplicity of diaphragm sheets each, respectively, substantially aligned with the first direction and configured to create a persistent watertight seal between the first corner post and the second corner post.

4. The system according to claim 3, comprising: a second multiplicity of tensioning strands configured and adapted to carry the second persistent tensile load in the second direction between the first corner post and a third corner post; and a second multiplicity of diaphragm sheets each, respectively, substantially aligned with the second direction and configured to create a persistent watertight seal between the first corner post and the third corner post.

5. The system according to claim 4, comprising: a third multiplicity of tensioning strands configured and adapted to carry a third persistent tensile load in a third direction between the second corner post and the third corner post; and a third multiplicity of diaphragm sheets each, respectively, substantially aligned with the third direction and configured to create a persistent watertight seal between the second corner post and the third corner post.

6. The system according to claim 4, comprising: a third multiplicity of tensioning strands configured and adapted to carry a third persistent tensile load in a third direction between the second corner post and a fourth corner post; a third multiplicity of diaphragm sheets each, respectively, substantially aligned with the third direction and configured to create a persistent watertight seal between the second corner post and the fourth corner post; a fourth multiplicity of tensioning strands configured and adapted to carry a fourth persistent tensile load in a fourth direction between the third corner post and the fourth corner post; and a fourth multiplicity of diaphragm sheets each, respectively, substantially aligned with the fourth direction and configured to create a persistent watertight seal between the third corner post and the fourth corner post.

7. The system according to claim 6, comprising: a first bisecting wall junction plate connecting two respective diaphragm sheets of the second multiplicity of diaphragm sheets; a second bisecting wall junction plate connecting two respective diaphragm sheets of the third multiplicity of diaphragm sheets; and a fifth multiplicity of diaphragm sheets each, respectively, substantially aligned with a fifth direction between the first bisecting wall junction plate and the second bisecting wall junction plate and configured to create a persistent watertight seal between the first bisecting wall junction plate and the second bisecting wall junction plate.

8. The system according to claim 7, comprising: a third bisecting wall junction plate connecting two respective diaphragm sheets of the second multiplicity of diaphragm sheets; a fourth bisecting wall junction plate connecting two respective diaphragm sheets of the third multiplicity of diaphragm sheets; a sixth multiplicity of diaphragm sheets each, respectively, substantially aligned with a sixth direction between the third bisecting wall junction plate and the fourth bisecting wall junction plate and configured to create a persistent watertight seal between the third bisecting wall junction plate and the fourth bisecting wall junction plate; a fifth bisecting wall junction plate connecting two respective diaphragm sheets of the fifth multiplicity of diaphragm sheets; a sixth bisecting wall junction plate connecting two respective diaphragm sheets of the sixth multiplicity of diaphragm sheets; and a seventh multiplicity of diaphragm sheets each, respectively, substantially aligned with a seventh direction between the fifth bisecting wall junction plate and the sixth bisecting wall junction plate and configured to create a persistent watertight seal between the fifth bisecting wall junction plate and the sixth bisecting wall junction plate.

9. The system according to claim 2, the first corner post comprising an extruded, formed, or rolled steel section and one or more weldments added thereto; the one or more weldments forming at least a portion of the first tab connector and at least a portion of the second tab connector; the one or more weldments comprising one or more members selected from the list comprising: flat stock, angle stock, C-channel, rod, tube, or box-section steel.

10. The system according to claim 9, the first corner post comprising a taper from a wider base dimension to a narrower top dimension.

11. The system according to claim 10, the first plate comprising a first multiplicity of holes configured to receive the first multiplicity of tensioning strands carrying the first persistent tensile load in the first direction; and the second plate comprising a second multiplicity of holes configured and adapted to receive a second multiplicity of tensioning strands carrying the second persistent tensile load in the second direction.

12. The system according to claim 7, first bisecting wall junction plate comprising: a body; a third tab connector fixedly attached to and extending from the body, the third tab connector configured to support a first diaphragm seal with a diaphragm sheet that is oriented substantially in a primary wall direction; a fourth tab connector fixedly attached to and extending from the body, the fourth tab connector configured to support a second diaphragm seal with a diaphragm sheet that is oriented substantially opposite the primary wall direction; and a fifth tab connector fixedly attached to and extending from the body, the fifth tab connector configured to support a third diaphragm seal with a diaphragm that is substantially oriented with a secondary wall angle that is at an angle to the primary wall direction.

13. The system according to claim 12, wherein the body comprises a T cross section.

14. The system according to claim 12, wherein the body comprises at least one cross section selected from the group consisting of a polygonal cross section, an oval cross section, and a round cross section.

15. The system according to claim 1, comprising: a first post-tensioned shotcrete wall bearing against the first bearing surface and substantially aligned with the first direction; and a second post-tensioned shotcrete wall bearing against the second bearing surface and substantially aligned with the second direction.

16. The system according to claim 1, comprising: a cast in place (CIP) concrete floor comprising one or more connection grooves configured and adapted to receive at least the first multiplicity of diaphragm sheets and provide a persistent watertight seal therewith.

17. A method for constructing a watertight and durable composite straight wall post-tensioned tank structure at a construction site, the method comprising: a) performing a site layout and surveying to establish sufficient precision and accuracy in a set of control points at the construction site; b) fine-grading a subgrade for proper elevation with respect to the set of control points; c) casting a set of working slabs on the subgrade and laying out edge forms thereon for a tank floor; d) setting floor steel and corresponding wall dowels within the edge forms; e) setting a groove formwork to create in the floor one or more corner connection grooves (CCG) and one or more wall connection grooves (WCG); f) casting concrete within the edge forms to create a floor comprising the CCG and WCG; g) allowing the floor to cure at least 12 hours to achieve a predetermined strength; h) stripping the groove formwork; i) setting a set of four corner posts into the CCG in the floor; j) confirming alignment, position, and plumb of each respective corner post; k) sealing each respective corner post into the CCG in the floor; l) erecting a multiplicity of diaphragm sheets and bisecting wall junction plates to form a respective diaphragm in each of two long, straight, external walls, with each respective diaphragm sheet and bisecting wall junction plate set in the WCG, mechanically connected to adjacent diaphragm sheet(s) or adjacent bisecting wall junction plate(s), or secured into a respective tab connector of each respective corner post to create a mechanical joint for future epoxy injection; m) sealing each respective diaphragm sheet, bisecting wall junction plate, and corner post into the WCG in the floor; n) positioning and tying a first layer of wall reinforcing steel on an exterior side of each respective diaphragm, to create a first layer of outer wall reinforcing steel; o) applying shotcrete in thin successive layers until the first layer of outer wall reinforcing steel is fully encapsulated between respective bearing surfaces of the respective corner posts at each end of each respective outer wall, forming a first outer layer of reinforced shotcrete; p) positioning a multiplicity of post-tensioning ducts and connecting a respective end of each duct to a respective corner post for each of the two long, straight, external walls; q) positioning and tying a second layer of wall reinforcing steel outside of the post-tensioning ducts, to create a second layer of outer wall reinforcing steel; r) applying shotcrete in thin successive layers until all outside components for the two long external walls are fully encapsulated between respective bearing surfaces of the respective corner posts at each end of each respective outer wall, forming a second layer of reinforced shotcrete; s) positioning and tying a third layer of wall reinforcing steel on the inside face of the diaphragm and bisecting wall junction plates for the two long external walls; and t) applying shotcrete in thin successive layers until the diaphragm, the top portion of the T directly connecting respective diaphragm sheets within the two long external walls of each respective bisecting wall junction plate, but not the shaft of the T that will connect to the diaphragm in each respective bisecting wall, and the third layer of wall reinforcing steel on the inside face of the diaphragm and bisecting wall junction plates are fully encapsulated between respective bearing surfaces of the respective corner posts at each end of each respective outer wall, forming a third layer of reinforced shotcrete to substantially complete the concrete structure of the two long external walls.

18. The method according to claim 17, comprising: u) building a first one of two perpendicular short external end walls and a center primary bisecting wall, following the steps (l) through (t), omitting bisecting wall junction plate(s) and tensioning ducts where not required; v) building two additional primary bisecting walls and one secondary bisecting wall therebetween, following the steps (l) through (t), omitting tensioning ducts where not required; and w) building a second one of two perpendicular short external end walls, following the steps (l) through (t), bisecting wall junction plate(s) and tensioning ducts where not required.

19. The method according to claim 18, comprising: x) epoxy sealing each respective vertical joint formed between each respective diaphragm sheet, bisecting wall junction plate, and corner post tab connector with epoxy injection; y) verifying proper concrete strength gain in at least one wall; z) inserting and threading through each respective post-tensioning duct a respective post-tensioning strand and attaching barrel bolts thereto at each respective end, bearing on each respective corner post; aa) post-tensioning all four external walls; and bb) after post-tensioning all four external walls, applying shotcrete in thin successive layers on and between respective tensioning surfaces of the respective corner posts at each end of each respective outer wall until the first layer of outer wall reinforcing steel is fully encapsulated, forming a first outer layer of reinforced shotcrete.

20. The method according to claim 19, comprising: cc) applying shotcrete to each external surface formed in the preceding steps, to create a smooth homogenous cover coat of shotcrete providing minimum coverage requirements and a joint-free surface, to produce the watertight and durable composite straight wall post-tensioned tank structure.

21. A persistent watertight post-tensioned concrete composite straight wall tank comprising: a first persistent watertight post-tensioned concrete composite corner; a second persistent watertight post-tensioned concrete composite corner; a third persistent watertight post-tensioned concrete composite corner; a first persistent watertight post-tensioned concrete composite straight wall connecting the first corner and the second corner; a second persistent watertight post-tensioned concrete composite straight wall connecting the second corner and the third corner; a third persistent watertight post-tensioned concrete composite straight wall connecting to the first corner; and a persistent watertight cast in place (CIP) concrete composite floor comprising one or more connection grooves aligned respectively with each of the first corner, the second corner, and the third corner, and one or more wall connection grooves aligned respectively with each of the first wall, the second wall, and the third wall.

22. The persistent watertight post-tensioned concrete composite straight wall tank according to claim 21, the third wall connecting the first corner and the third corner to form a triangular tank.

23. The persistent watertight post-tensioned concrete composite straight wall tank according to claim 21, comprising: a fourth persistent watertight post-tensioned concrete composite corner; and a fourth persistent watertight post-tensioned concrete composite straight wall connecting the third corner and the fourth corner; the third wall connecting the first corner and the fourth corner; and the fourth wall connecting the fourth corner and the third corner to form a quadrilateral tank; and the floor comprising one or more connection grooves aligned respectively with each of the each of the fourth corner, and the fourth wall.

24. The persistent watertight post-tensioned concrete composite straight wall tank according to claim 23, wherein the third wall forms a first corner angle relative to the first wall at the first corner and the second wall forms a second corner angle relative to the first wall at the second corner; the first corner angle and the second corner angle each respectively being substantially equal to 90.

25. The persistent watertight post-tensioned concrete composite straight wall tank according to claim 24, wherein the fourth wall forms a third corner angle relative to the second wall at the third corner and the fourth wall forms a fourth corner angle relative to the third wall at the fourth corner; the third corner angle and the fourth corner angle each respectively being substantially equal to 90, thus forming a square or rectangular tank.

26. The persistent watertight post-tensioned concrete composite straight wall tank according to claim 24, wherein the fourth wall forms a third corner angle relative to the second wall at the third corner and the fourth wall forms a fourth corner angle relative to the third wall at the fourth corner; the third corner angle being greater than 90; and the fourth corner angle being less than 90, thus forming an irregular four-sided polygonal tank.

27. The persistent watertight post-tensioned concrete composite straight wall tank according to claim 23, comprising: a total of n persistent watertight post-tensioned concrete corners, where n is a positive integer greater than or equal to 3; and a total of n persistent watertight post-tensioned concrete composite straight walls; each wall respectively connecting a respective corner with exactly one other corner; each corner respectively connecting a respective wall with exactly one other wall to form a closed and non-intersecting n-dimensional polygonal tank; and the floor being configured and adapted to support a persistent watertight seal between the floor and each respective wall and corner.

28. The persistent watertight post-tensioned concrete composite straight wall tank according to claim 21, comprising: a first internal diaphragm encased substantially within the post-tensioned concrete of the first wall; a second internal diaphragm encased substantially within the post-tensioned concrete of the second wall; and a third internal diaphragm encased substantially within the post-tensioned concrete of the third wall; one or more of the connection grooves in the floor aligned respectively with, and configured and adapted to receive and support a seal to a portion of each of the first internal diaphragm, the second internal diaphragm, and the third internal diaphragm, respectively.

29. The persistent watertight post-tensioned concrete composite straight wall tank according to claim 28, wherein each respective diaphragm comprises a multiplicity of diaphragm sheets joined together with persistent watertight seals.

30. The persistent watertight post-tensioned concrete composite straight wall tank according to claim 28, comprising: a first sealed and loaded corner post forming a portion of the first corner and configured and adapted to: provide persistent post-tension to the first wall, provide persistent post-tension to the third wall, support a persistent seal with the first internal diaphragm, and support a persistent seal with the third internal diaphragm; the floor comprising one or more connection grooves each respectively configured and adapted to receive therein and support a respective persistent seal with the first sealed and loaded corner post.

31. The persistent watertight post-tensioned concrete composite straight wall tank according to claim 21, comprising: a first persistent watertight concrete bisecting junction; a second persistent watertight concrete bisecting junction; and a first persistent watertight concrete composite straight bisector connecting the first bisecting junction and the second bisecting junction, the first bisector substantially encasing a first bisecting diaphragm therein; the first bisecting junction comprising a first bisecting junction plate encased substantially within and forming a connection between the second wall and the first bisector; the second bisecting junction comprising a second bisecting junction plate encased substantially within and forming a connection between the third wall and the first bisector; the floor comprising one or more connection grooves each respectively configured and adapted to receive therein and support a respective persistent epoxy seal with the first bisecting diaphragm, the first bisecting junction plate, and the second bisecting junction plate.

32. The persistent watertight post-tensioned concrete composite straight wall tank according to claim 31, comprising: a third persistent watertight concrete bisecting junction; a fourth persistent watertight concrete bisecting junction; a fifth persistent watertight concrete bisecting junction; a sixth persistent watertight concrete bisecting junction; a second persistent watertight concrete composite straight bisector connecting the third bisecting junction and the fourth bisecting junction, the second bisector substantially encasing a second bisecting diaphragm therein; and a third persistent watertight concrete composite straight bisector connecting the fifth bisecting junction and the sixth bisecting junction, the third bisector substantially encasing a third bisecting diaphragm therein; the third bisecting junction comprising a third bisecting junction plate encased substantially within and forming a connection between the second wall and the first bisector; the fourth bisecting junction comprising a fourth bisecting junction plate encased substantially within and forming a connection between the third wall and the first bisector; the fifth bisecting junction comprising a fifth bisecting junction plate encased substantially within and forming a connection between the first bisector and the second bisector; the sixth bisecting junction comprising a sixth bisecting junction plate encased substantially within and forming a connection between the first bisector and the second bisector; the floor comprising one or more connection grooves each respectively configured and adapted to receive therein and support a respective persistent epoxy seal with the second bisecting diaphragm, the third bisecting diaphragm, the third bisecting junction plate, the fourth bisecting junction plate, the fifth bisecting junction plate, and the sixth bisecting junction plate.

33. The persistent watertight post-tensioned concrete composite straight wall tank according to claim 32, comprising: a seventh persistent watertight concrete bisecting junction; an eighth persistent watertight concrete bisecting junction; and a fourth persistent watertight concrete composite straight bisector connecting the seventh bisecting junction and the eighth bisecting junction, the fourth bisector substantially encasing a fourth bisecting diaphragm therein; the seventh bisecting junction comprising a seventh bisecting junction plate encased substantially within and forming a connection between the second wall and the fourth bisector; the second bisecting junction comprising an eighth bisecting junction plate encased substantially within and forming a connection between the third wall and the fourth bisector; the floor comprising one or more connection grooves each respectively configured and adapted to receive therein and support a respective persistent epoxy seal with the fourth bisecting diaphragm, the seventh bisecting junction plate, and the eighth bisecting junction plate.

34. The persistent watertight post-tensioned concrete composite straight wall tank according to claim 21, comprising: a first plurality of post-tensioning ducts encased within the first wall and connected at opposing ends between the first corner and the second corner, each respective duct of the first plurality of ducts covering at least one respective strand of a first plurality of post-tensioning strands configured and adapted to carry a first tensile load between the first corner and the second corner; and a second plurality of post-tensioning ducts encased within the second wall and connected at opposing ends between the second corner and the third corner, each respective duct of the second plurality of ducts covering at least one respective strand of a second plurality of post-tensioning strands configured and adapted to carry a second tensile load between the second corner and the third corner; wherein the first corner and the second corner are configured and adapted to bear the first tensile load and transfer the first tensile load into a first persistent compression in the first wall; and wherein the second corner and the third corner are configured and adapted to bear the second tensile load and transfer the second tensile load into a second persistent compression in the second wall.

35. The persistent watertight post-tensioned concrete composite straight wall tank according to claim 21, having a liquid storage capacity between 15,000 gallons and 1.5 million gallons, a wall height greater than 15 feet, and a measured leakage of less than 0.05% per day, based on volume.

36. A sealed and loaded corner post useful for providing concurrent structural support, post-tensioning, and watertight sealing, the sealed and loaded corner post comprising: a first bearing surface defining a first direction effectively normal thereto, the first bearing surface configured and adapted to transmit a first persistent compressive load oriented substantially in the first direction; a second bearing surface defining a second direction effectively normal thereto, the second bearing surface configured and adapted to transmit a second persistent compressive load oriented substantially in the second direction, the second direction separated from the first direction by a corner angle; a first tab connector configured and adapted to support a first persistent watertight diaphragm seal with a diaphragm sheet that is oriented substantially in the first direction; and a second tab connector configured and adapted to support a second persistent watertight diaphragm seal with a diaphragm sheet that is oriented substantially in the second direction; the sealed and loaded corner post configured and adapted to provide structural support for the first persistent compressive load and the second persistent compressive load; and the sealed and loaded corner post configured and adapted to provide a persistent watertight connection between the first tab connector and the second tab connector.

37. The sealed and loaded corner post according to claim 36, comprising: a third bearing surface defining a third direction effectively normal thereto, the third bearing surface configured and adapted to transmit a third persistent compressive load oriented substantially in the second direction, the corner angle being a first corner angle, and the third direction separated from the first direction by a second corner angle; and a third tab connector configured and adapted to support a third persistent watertight diaphragm seal with a diaphragm sheet that is oriented substantially in the third direction; the sealed and loaded corner post configured and adapted to provide structural support for the third persistent compressive load; and the sealed and loaded corner post configured and adapted to provide a persistent watertight connection between the first tab connector and the third tab connector, and between the third tab connector and the second tab connector.

38. A persistent watertight concrete bisecting junction useful in the construction of a persistent watertight post-tensioned concrete composite straight wall tank, the persistent watertight concrete bisecting junction comprising: a first straight concrete wall substantially oriented in a first direction, the first wall encasing a first diaphragm sheet and a second diaphragm sheet; a second straight concrete wall bisecting the first wall and forming a corner angle therebetween, the second wall encasing a third diaphragm sheet; a bisecting junction plate encased substantially within and forming a structural connection between the first wall and the second wall, bisecting junction plate connected to and forming a respective persistent watertight seal with each of the first diaphragm sheet, the second diaphragm sheet, and the third diaphragm sheet, respectively; and a floor supporting each of the first wall, the second wall, and the bisecting junction plate, the floor comprising one or more connection grooves each respectively configured and adapted to receive a respective portion therein and support a respective persistent watertight seal with each of the bisecting junction plate, the first diaphragm sheet, the second diaphragm sheet, and the third diaphragm sheet, respectively.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIGS. 1A-1B illustrate a plan view and a section view of a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The respective location for each of FIGS. 1B, 3A, 3B, 4A, 5B, 6A, and 6B is indicated in FIG. 1A. Although FIG. 1A is primarily a plan view of a finished concrete structure, the locations of corner posts with tensioning strands and bisecting wall junction plates have been indicated by simplified representations of certain embodiments thereof. These representations are not intended to show all details of the respective corners or junctions for the illustrated embodiment, nor to represent any of the numerous other contemplated embodiments, and should not be considered limiting the scope of the subject invention, nor the disclosure of any respective views in later figures.

[0012] FIGS. 2A-2D illustrate plan, perspective, and detailed views of a concrete floor slab for a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The respective location for each of FIGS. 2C and 2D is indicated in each of FIGS. 2A and 2B.

[0013] FIGS. 2E-2H illustrate plan, perspective, and detailed views of a concrete floor slab with four corner posts erected for a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The respective location for each of FIGS. 2G and 2H is indicated in each of FIGS. 2E and 2F.

[0014] FIGS. 3A-3F illustrate partial section and detailed views of a concrete floor slab, wall, diaphragm, raw epoxy channel (FIGS. 3A and 3D), and epoxy sealed waterstop (FIGS. 3B, 3C, 3E, and 3F) for a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The respective location for each of FIGS. 3A, 3B, and 3C is indicated in FIG. 1A. The location for FIG. 3D is indicated in FIG. 3A. The location for FIG. 3E is indicated in FIG. 3B. The location for FIG. 3F is indicated in FIG. 3C.

[0015] FIGS. 4A-4C illustrate plan, partial section, and perspective views of a concrete floor slab, diaphragm, L-shaped structural corner, and epoxy sealed waterstop for a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The location for FIG. 4B is indicated in FIG. 4A. A first diaphragm sheet (running down in FIG. 4A, towards the viewer in FIG. 4B, and angled to the right in FIG. 4C) is shown in each of FIGS. 4A-4C, respectively, but a second diaphragm sheet (running left in each of FIGS. 4A and 4B, respectively, and angled to the left in FIG. 4C) is shown in each of FIGS. 4A and 4B, respectively, but hidden for clarity in FIG. 4C.

[0016] FIGS. 4D-4F illustrate plan, partial section, and perspective views of a concrete floor slab, diaphragm, hollow box-shaped structural corner, and epoxy sealed waterstop for a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The location for FIG. 4E is indicated in FIG. 4D. A first diaphragm sheet (running down in FIG. 4D, towards the viewer in FIG. 4E, and angled to the right in FIG. 4F) is shown in each of FIGS. 4D-4F, respectively, but a second diaphragm sheet (running left in each of FIGS. 4D and 4E, respectively, and angled to the left in FIG. 4F) is shown in each of FIGS. 4D and 4E, respectively, but hidden for clarity in FIG. 4F.

[0017] FIGS. 5A-5E illustrate perspective, plan, and detail views of a partially erected structure comprising four L-shaped structural corner members, eight T-shaped bisecting wall junctions, tensioning ducts, tensioning tendons, and barrel connectors prior to application of shotcrete, for a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The location for FIG. 5B is indicated in FIG. 1A. The location for FIG. 5C is indicated in FIG. 5A. The location for FIG. 5E is indicated in FIG. 5D. Certain diaphragm sheets, the outline of the floor slab, and the outline of the base of the tapered shotcrete walls are shown in FIG. 5B, but hidden for clarity in FIG. 5A and FIG. 5C, respectively. FIG. 5D illustrates additional details from FIG. 5B, and FIG. 5E illustrates a detailed view of the area around one tab connector 430 as indicated in FIG. 5D.

[0018] FIGS. 6A-6E illustrate plan, perspective, and detail views of an erected structure for a bisecting to bisecting wall junction (FIG. 6A) and a post-tensioned wall to bisecting wall junction (FIG. 6B), each respectively comprising a T-shaped structural bisecting wall junction plate connected between first and second diaphragm sheets in the main wall and a third diaphragm sheet in the bisecting wall, assembled prior to application of shotcrete (e.g., as shown in FIGS. 6C-6E) and in a no-hidden-line view showing the finished top edges of the shotcrete wall (e.g., as shown in FIGS. 6A-6B) for a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The respective location for each of FIGS. 6D and 6E is indicated in FIG. 6C. A representative respective location for each of FIGS. 6A and 6B is indicated in FIG. 1A.

[0019] FIG. 7 illustrates a cutaway blackline view of a wall section for a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The full-depth shotcrete is cut away to show the internal structure of the wall.

[0020] FIGS. 8A-8D schematically illustrate exemplary and non-limiting embodiments according to Embodiment 21 (FIG. 8A), Embodiment 22 (FIG. 8B), Embodiment 23 (FIG. 8C), and Embodiment 31 (FIG. 8D), each respectively according to an embodiment of the subject invention.

DETAILED DISCLOSURE OF THE INVENTION

[0021] Embodiments of the subject invention provide a liquid-containing, composite, straight wall watertight tank structure comprising a cast-in-place floor section, at least three straight wall sections and at least 3 corner sections, each corner section respectively joining two or more straight wall sections, referred to hereinafter as a watertight composite straight wall post-tensioned concrete tank, a watertight straight wall tank, or simply a tank. In one embodiment a square tank is provided, with four equal length wall sections joined by four respective 90-degree corners. In another embodiment a rectangular tank is provided with a first pair of opposed, parallel, equal length, straight wall sections having a first length and a second pair of opposed, parallel, equal length, straight wall sections having a second length, the second length (e.g., 200 m) greater than the first length (e.g., 100 m), and each pair of wall sections respectively joined by one of four respective 90-degree corners.

[0022] In certain embodiments, a generally polygonal tank is provided with three or more straight wall sections of varying lengths (wherein some lengths, optionally, can be the same between two or more wall sections) joined by a corresponding number of corners, wherein the sum of the measure of the interior angles is ((n2)*180) degrees (e.g., 90, 80, 80, and 110-degree corners respectively joining n=4 wall sections of various lengths; or 90, 90, 120, 130, and 110-degree corners respectively joining n=5 wall sections of various lengths; or 90, 60, 90, and 120-degree corners respectively joining n=4 wall sections of various lengths; or 90, 30, and 60-degree corners respectively joining n=3 wall sections of various lengths, as specified to maximize storage capacity within an available space in a facility site plan (e.g., in a water treatment plant, chemical storage, or other application dealing with large volumes of liquids in the thousands to millions of gallons).

[0023] In other embodiments, a regular polygon where all sides are of equal length and all angles are equal, such as 6 equal sides and 6 corners of 120-degrees each, or 3 equal sides and 3 corners of 60-degrees each, forming a perimeter that is optimized to fill an available space and maximize utilization at a site.

[0024] As used herein, liquid-containing refers to any structure that is designed and constructed to store liquids.

[0025] As used herein a watertight tank is one that inhibits the measurable exit of the liquid contents from inside the tank passing through any portion of the tank to the outside, as would result in a measurable loss in the volume of the stored liquid via commercially viable measurement techniques known in the art and commonly used in industrial applications. For example, the American Water Works Association (AWWA) in standards D110 & D115 define water tightness for round or oval post-tensioned concrete water tanks with allowable leakage of 0.05% of total volume per day when adjusted for evaporation and other specified factors, or about 500 gallons per day per million gallons of capacity. Stating in part, Properly designed, constructed, and crack-free concrete is, for all intents and purposes, impermeable to water. With a permeability of 510.sup.14 m/s (for cement paste with a water/cement ratio of 0.45), the loss through the wall and floor of a typical 5-mil-gal tank would be less than one-half gallon per 72 h. Many tanks have been constructed and found to have no measurable leakage when tested for watertightness. Loss of water can occur, however, because of lower-grade workmanship at honeycombed, cracked, or other defective areas in the floors or walls or through leaks in the piping and valves.

[0026] Tanks (e.g., watertight composite straight wall post-tensioned concrete tanks) according to certain embodiments of the subject invention are watertight as evidenced by a measured loss of less than 0.5% of total volume per day, alternatively less than 0.05% of total volume per day, alternatively less than 0.005% of total volume per day, alternatively less than 0.0005% of total volume per day, or alternatively less than the minimum amount that can be measured with commercially reasonable methods in the field.

[0027] Embodiments of the subject invention provide a corner post comprising a structural member and two or more epoxy joints. The structural member can be, by way of example and not limitation, a box section, an L section, a T section, a V section, or any other suitable section that can be configured and adapted to support a suitable tension load from tensioning strands and transmit the tensile force into a compressive load bearing on one or more attached post-tensioned tank walls, producing a persistent compression through the one or more tank walls. The compressive load transmitted through a first attached tank wall can be at an angle of 90 relative to a second attached tank wall as would be useful to form a square or rectangular tank, or alternatively at any practical and functional angle between 0 and 360 measured as shown in FIG. 5B. While in certain embodiments it can be more practical, more cost efficient, or less complex to provide a corner post supporting a first post-tensioned walls at an angle closer to 90 relative to a second post-tensioned wall (e.g., at an angle between 45 and 135), embodiments can provide a corner post with sufficient clearance, separation, and access as needed to form and post-tension two or more walls at any required angle. It is further contemplated within the scope of the subject invention that certain embodiments can provide a corner post supporting a single post-tensioned wall, or three or more post-tensioned walls meeting at or near a respective corner. The structures surrounding and/or creating the provided epoxy joints can comprise weldments, extruded features, attachments, sheet metal, plastics, or other structures suitable to provide a sealing channel around, at, in contact with, within, beside, or adjacent to an end or other attachment of a diaphragm. Embodiments provide tab connector joints that physically retain a diaphragm sheet end, account for respective allowable variance(s) in construction, location, assembly, and positioning of the diaphragm sheet and corner post, and provide a controlled, clean, and properly sized seal pocket for an exothermic curing reaction following an epoxy sealant application.

[0028] Certain embodiments provide a corner post connecting the floor and two straight walls using post-tensioned strands to put the system into persistent compression. For example, in certain non-limiting embodiments, with a minimum of 100 psi (alternatively 50, 80, 90, 110, 120, 150, 200, 300, or 500 psi, including increments, combinations, and ranges of any of the foregoing) of residual compression. The provided corner post allows for both constant thickness and tapered thickness straight walls. Constant thickness wall embodiments can offer advantages of simplicity in design and construction, with sufficient strength for the application (e.g., in walls up to about 3 meters or about 10 feet in height.) Tapered thickness wall embodiments can offer advantages of efficiency in cost and material requirements, with sufficient strength for the application (e.g., in walls above about 3 meters or about 10 feet in height.)

[0029] In certain embodiments the corner post provides a new and unique approach to creating a watertight liquid-containing tank. Embodiments provide an epoxy injected tab detail (e.g., as illustrated in FIGS. 4A-4C) allowing the positive connection of a galvanized steel diaphragm to be integral with straight walls. Embodiments provide a pvc floor seal (e.g., as illustrated in FIG. 3D) connecting the floor and corner post with an epoxy seal. Embodiments provide embedded strands (e.g., as illustrated in FIG. 5A-5C) that allow the straight walls and column to be connected as a system and then put into persistent compression to inhibit localized cracking.

[0030] In certain embodiments the corner post once filled with or set in concrete (e.g., as illustrated in FIGS. 5A-5C) provides a bearing member, surface, or zone for the post tensioning strands that inhibits tensile stress bulbs from radiating beyond the steel column into the straight wall section.

[0031] Embodiments provide a bisecting wall junction plate (e.g., as illustrated in FIGS. 6A-6B) wherein the bisecting wall junction plate is sealed to the floor and respective diaphragm sheets of exterior and/or interior wall to provide a watertight seal at selected interfaces from floor to wall, from a first post-tensioned (e.g., exterior) wall to second non-tensioned (e.g., interior) wall, or from a first non-tensioned (e.g., interior) wall to second non-tensioned (e.g., interior) wall. It is further contemplated within the scope of the subject invention that certain embodiments can provide post-tensioned interior walls wherein the post-tensioning can be supported by a corner post bearing a tensile load from a multiplicity of tensioning strands and transferring that load as a persistent compressive load into a respective post-tensioned interior walls.

[0032] The bisecting wall junction is a unique connection device that allows two or more integral steel diaphragms meeting at an intersection of a bisecting wall to be connected with an epoxy injected watertight seal. In certain embodiments the bisecting wall junction provides a new and unique plate constructed with respective welded receiving tabs to receive the respective diaphragm sheets (e.g., three diaphragm sheets as illustrated in FIGS. 6A-6E). In certain embodiments the bisecting wall junction utilizes a pvc floor seal (e.g., as illustrated in FIG. 3D) connecting the floor and plate with an epoxy seal. In certain embodiments a reinforced (alternatively, non-reinforced) bisecting wall junction plate provides the termination of one or more interior walls into an exterior wall.

[0033] In certain embodiments the bisecting wall junction plate is designed and constructed as a hydrostatically independent shotcrete plate, meaning that a first volume of liquid on a first side of the bisecting wall junction plate or any attached wall can be empty, while a second volume of liquid on a second side of the bisecting wall junction plate or attached wall can be empty, and even in this extreme load condition, the bisecting wall junction plate and/or attached wall can still be watertight. The connection of the tensioned (e.g., exterior) wall and non-tensioned (e.g., interior or bisecting) wall happens on the opposite side of the tensioning strands in the tensioned wall (e.g., as illustrated in FIGS. 6A-6B). Traditional reinforcement is mechanically connected to the bisecting wall junction plate, allowing for the development of the reinforcement and fixed connection of the bisecting wall to the tensioned wall (e.g., as illustrated in FIG. 6B).

[0034] In certain embodiments (e.g., embodiments designed and/or constructed in compliance with ACI 350), the bisecting wall design incorporates a minimum of 0.5% reinforcing steel in both directions (e.g., horizontal and vertical) to control and minimize crack widths. The unique integral steel diaphragm inhibits water from migrating through the section of the bisecting wall.

[0035] In certain embodiments the steel shell diaphragm (e.g., galvanized or non-galvanized, alternatively any suitable metal, polymer, composite, or other material providing sufficient strength, rigidity, robustness, longevity, watertightness, and sealing properties). creates an opposing pair of open, exposed, or form-free self-supporting surfaces on which the shotcrete is applied to both surfaces, creating a mechanical key between the shotcrete and the diaphragm. The angles and features of the diaphragm can create a mechanical bond between the shotcrete and the diaphragm, inhibiting the shotcrete from delaminating and inhibiting the formation of voids therebetween.

[0036] While certain prestressed circular or oval (e.g., AWWA D110). tanks are known to have a similar diaphragm (e.g., in Type II, III, and IV wall construction methodology), conventional precast and cast in place straight wall tanks are not. Embodiments of the subject invention advantageously apply the novel combination of sealing and tensioning elements described herein to provide new and uniquely functional watertight composite straight wall post-tensioned concrete tanks.

[0037] In certain embodiments the diaphragm is supported from inside the tank during construction using a wall erection system. The diaphragm can be initially held vertically by clips known in the art that utilize the reentrant angles to hold tight against a series of wall ribs that inhibit the diaphragm from excessive vibration during the shotcrete application. The wall erection system can be removed after the shotcrete has added sufficient structure (e.g., after the exterior core wall is at least 50% complete or has reached at least half of the desired thickness.) In certain embodiments the diaphragm is continuous from the bottom to the top of the wall, with no horizontal joints or splices permitted. The vertical joints can be roll-seamed, crimped, and/or sealed watertight using epoxy injection. The entirety, the majority, all, essentially all, or effectively all of the diaphragm can be encased and finished in shotcrete, creating a joint-free surface on the interior and exterior of the tank.

[0038] As used herein, concrete refers to the primary building material, which can be reinforced, prestressed, or post-tensioned to enhance its load-bearing capabilities and reduce cracking. A composite concrete wall is a specialized type of wall that in certain embodiments integrates a galvanized steel shell diaphragm (e.g., 26-gauge, alternatively 22-gauge, 28 gauge, or any other size that provides sufficient strength and stability for the construction process together with longevity and watertightness) as a positive waterstop covered with pneumatically applied concrete (e.g., shotcrete) and further tensioned with steel and reinforcing elements to maximize structural strength and long-term durability.

[0039] In certain embodiments the steel diaphragm used in the construction of the core wall can be 26 gauge with a minimum thickness of 0.43 mm (0.017 in.), conforming to the requirements of ASTM A653/A653M. The weight of zinc coating can be not less than G 90 of Table 1 of ASTM A653/A653M (e.g., galvanized steel hot dipped in zinc and coated with a minimum 0.027 g/cm.sup.2 (0.90 oz./ft.sup.2) of zinc (both sides), 0.014 g/cm.sup.2 (0.45 oz./ft.sup.2) of zinc (one side), or 20.6 m (0.00081 inches) thickness per side.)

[0040] In certain embodiments additional materials or components, such as steel reinforcement or carbon fiber elements, are integrated into the concrete to improve specific properties like tensile strength, flexural strength, or resistance to environmental factors.

[0041] As used herein, post-tensioned means that the concrete in the wall is subjected to compressive stresses after curing to sufficient strength but before being subjected to external loads, which helps counteract potential tensile stresses during its service life. Composite post-tensioned concrete walls are commonly used in construction for structures that require high strength, durability, and resistance to various forces, such as retaining walls, bridges, and industrial buildings.

[0042] As used herein, wall section means a construct comprising multiple structural layers, including inner shotcrete, outer shotcrete, galvanized steel shell diaphragm, reinforcement, and post-tensioning strand.

[0043] In certain embodiments a critical component of the construction of a composite wall can be to ensure the diaphragm and shotcrete are well bonded. To accomplish this, pneumatically applied concrete can be applied to the wall at such velocity to allow for self-consolidation and encapsulation around the reentrant angles of the diaphragm to create a mechanical key between the diaphragm and the surrounding concrete.

[0044] In certain embodiments the shotcrete surfaces of the interior and exterior of the tank are finished to achieve a visually pleasing and uniform appearance with minimal bumps, ridges, or roughness and free of cold joints. The smooth finished shotcrete surface provided by certain embodiments of the subject invention offers several benefits, including the following. A smooth finished shotcrete surface minimizes the chances of solids and debris sticking to the tank's interior, helping to maintain a cleaner environment inside the tank and reducing the frequency of cleaning and maintenance, promoting smoother flow across the shotcrete section, and ensuring the treatment process operates efficiently. A smooth finished shotcrete surface is easier to clean when the tanks are taken down for inspection and cleaning, returning the structure into service faster. A smooth finished shotcrete surface is less susceptible to damage from abrasive materials in the wastewater which can extend the tank's life. A smooth finished shotcrete surface combined with a high cement content mix design (e.g., a minimum of 800 lbs of cement per cubic yard or equivalent formulation including alternatives to cement products that are known in the art, such as fly-ash, slag, and the like) improves resistance to corrosion.

[0045] A cold joint refers to the discontinuity or seam in a concrete structure where two applications of concrete have been poured/placed and allowed to harden at different times, creating a boundary or interface between the two sections. Cast-in-place tanks can have both vertical and horizontal joints due to the limitations of the forming system. Pre-cast panel tanks typically only have vertical but more frequent cold joints. Cold joints can be a concern because they can present a potential weak point where water could leak. Special treatment must occur at each joint, often requiring a coating system as the ultimate barrier material to inhibit leakage. This coating system creates a long-term maintenance concern for the tank.

[0046] In certain embodiments the interior wall can have rounded shotcrete corner coves (e.g., corners having a minimum bend radius of 2 inches, alternatively, 3, 4, 5, 6, 8, 12, 18, 24, or 36 inches, including increments, combinations, and ranges of any of the foregoing) that provide a continuous and monolithic interior shotcrete surface throughout a portion of, or the entirety of the tank.

[0047] In certain embodiments the diaphragm can be protected against damage before, during, and after erection. Holes can be avoided in the diaphragm except for inserting wall pipes or sleeves, reinforcing steel, bolts, or other special appurtenances. Such penetrations can be sealed with an epoxy sealant (e.g., a sealant that complies with the requirements of ASTM C881/C881M.)

[0048] A known concerning when building with concrete is the presence of porous spaces between the sand and cement particles, which allows water to permeate or migrate through traditional concrete sections. When the liquid contents are allowed to migrate through the section, issues can develop, such as weakening the structure by corroding the reinforcement, causing it to expand and eventually spall (e.g., break, chip, crack, or pit) the concrete.

[0049] A key component of the design and construction of the wall section in certain embodiments is keeping the diaphragm in the intended vertical plane thereby complying with minimum cover requirements to create a full height waterstop (e.g., up to or above the designed water height), around the entire perimeter throughout the entire wall section.

[0050] The diaphragm, when combined with the unique construction process, corner posts, bisecting wall junction plates, epoxy seals, and waterstops, creates a watertight connection with the floor, the straight post-tensioned (e.g., outer) walls, and the non-tensioned bisecting (e.g., internal) walls. In certain embodiments the corner post has tabs in multiple directions (e.g., as illustrated in FIGS. 4A-4C) that allow for the positive connection of the galvanized steel diaphragm creating a watertight barrier beneath the surface of the shotcrete in two or more straight walls. Embodiments of the subject invention provide tabs added to or integrally formed as a part of the corner post, bisecting wall junction plate, and/or waterstop, the tabs forming an epoxy sealing groove and allowing for a positive and watertight seal between each corner post, bisecting wall junction plate, and/or waterstop, respectively, and each adjacent diaphragm sheet.

[0051] The corner post can be configured and adapted to put each connected wall into persistent compression through tension carried in the tensioning strands, thereby protecting the wall from tensile stresses. Embodiments of the provided corner post are uniquely designed to carry these tensile stresses in the corners without allowing cracks to open in the straight tensioned wall sections, as in related art solutions that can utilize the tensile reinforcement located in the wall section. The corner post inhibits cracks that can create long-term maintenance and watertightness/retention/leakage issues associated with cast-in-place structures. The full-height waterstop created by the integral diaphragm sealed to the corner post, combined with the integrated shotcrete covering, greatly inhibits cracks and cold joints to provide a unique and superior structural and sealing solution to inhibit the water from permeating through the wall section.

[0052] In certain embodiments the wall/floor connection provides a slot formed in the floor and receiving epoxy-injected 26-gauge galvanized steel diaphragm sheets. Embodiments provide a pvc floor seal connecting the floor, wall, bisecting wall junction plates, diaphragm, and corner posts with an epoxy seal. The combination comprising one or more of corner post, diaphragm, bisecting wall junction plate, and floor seal in certain embodiments creates an efficient, economical, and maintenance free watertight connection between two or more walls at one or more specified angles.

[0053] Embodiments of the subject invention advantageously employ pneumatically applied concrete (e.g., shotcrete) that is designed to flow into place without the need for mechanical vibration or compaction.

[0054] Concrete (including shotcrete) is durable for several reasons, including the following. Strength: concrete is a strong material that can resist heavy compressive loads. This inherent strength allows it to endure various stresses. Chemical Stability: concrete is chemically stable and resistant to many environmental factors. Also, it does not naturally corrode or rust like some metals, making it an ideal choice for long-term use. Weather resistance: concrete can withstand a wide range of weather conditions, from extreme heat to freezing cold. Longevity: properly designed and constructed concrete structures can last for many decades or even centuries.

[0055] Porosity in concrete refers to the presence of tiny, interconnected voids or open spaces within the concrete section. These voids can be filled with air or water and are typically the result of incomplete compaction at the time of placement, which can have a significant impact on the durability of the section. Concerns associated with porous sections include the following. Reduced Strength: porous concrete is generally weaker than dense, low-porosity concrete because the voids compromise the material's structural integrity. Permeability: porous concrete is more permeable, allowing water, chemicals, and gases to penetrate more quickly through the section. This can lead to issues like corrosion of the steel reinforcement and deterioration of the concrete section. Freeze-Thaw Damage: in cold climates, water that enters porous concrete can freeze and expand, causing cracks and damage over time. Chemical Attack: porous concrete is more susceptible to chemical attack from aggressive substances such as acids and sulfates which can degrade the concrete section.

[0056] The floor section in certain embodiments can be designed and constructed in accordance with applicable sections of appropriate building construction codes such as ACI 117 and ACI 350 (ACI SPEC-117-10: Specification for Tolerances for Concrete Construction and Materials and ACI CODE-350-06 Code Requirements for Environmental Engineering Concrete Structures American Concrete Institute, Farmington Hills, Michigan) which state in part, for example, that the floor will meet or exceed the following requirements: [0057] a. 4000 psi concrete with type I/IL cement, aggregate, 5+/slump, and soft broom finish, [0058] b. Concrete working slab, if used, shall be no less than 3.5 in. thick. [0059] c. Minimum top cover of 2 in. and minimum bottom cover of 3 in. [0060] d. Minimum reinforcing of 0.50% in the floor. [0061] e. Minimum reinforcing of 0.3% in the vertical and 0.5% in the horizontal wall.

[0062] As used herein straight wall means the wall being effectively free of curves and/or bends, creating a linear section following a direct path. In certain embodiments the wall can be designed and constructed in accordance with applicable tolerances of ACI 117, including: [0063] a. Wall shall be vertically plumb within over 10 ft [0064] b. Wall thickness shall not deviate by more than and + [0065] c. Top of wall to not deviate more than +/1 in the horizontal direction. [0066] d. The wall shall not have more than 1 of bowing

[0067] In certain embodiments the straight wall can be measured during construction for alignment and compliance with the design tolerances at each of the following phases: [0068] a. Forming of wall connection device. [0069] b. Corner post horizontal and vertical alignment. [0070] c. Erection of Diaphragm support system for horizontal and vertical alignment. [0071] d. Erection of Diaphragm sheets for horizontal and vertical alignment. [0072] e. Top of Wall elevation and horizontal alignment. [0073] f. Diaphragm and corner post for proper angle alignment.

[0074] Turning now to the figures, FIGS. 1A-1B illustrate a plan view and a section view of a watertight composite straight wall post-tensioned concrete tank structure (100) according to an embodiment of the subject invention. The respective location for each of FIGS. 1B, 4A, 5B, 6A, and 6B is indicated in FIG. 1A. Floor 130 is seen supporting post-tensioned walls 120, joined by corners 110 around the perimeter of the tank, and a total of seven bisecting walls 160 between bisecting wall junctions 140, subdividing the tank into smaller sections.

[0075] FIGS. 2A-2D illustrate plan, perspective, and detailed views of a concrete floor slab for a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The respective location for each of FIGS. 2C and 2D is indicated in each of FIGS. 2A and 2B. Grooves 210 are formed in floor 130 to seal both walls and corners to the floor. The wall connecting grooves seen in FIG. 2C can be adapted to any shape of a corner post for sealing of the post to the floor with epoxy sealant or another suitable sealant after the floor has been cast. Alternatively, corner posts can be set directly into the wet concrete of the floor while it is poured. as shown in FIGS. 2E-2H.

[0076] FIGS. 2E-2H illustrate plan, perspective, and detailed views of a concrete floor slab with four corner posts erected for a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The respective location for each of FIGS. 2G and 2H is indicated in each of FIGS. 2E and 2F.

[0077] FIGS. 3A-3F illustrate partial section and detailed views of a concrete floor slab, wall, diaphragm, raw epoxy channel (FIGS. 3A and 3D), and epoxy sealed waterstop (FIGS. 3B, 3C, 3E, and 3F) for a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The respective location for each of FIGS. 3A, 3B, and 3C is indicated in FIG. 1A. The location for FIG. 3D is indicated in FIG. 3A. The location for FIG. 3E is indicated in FIG. 3B. The location for FIG. 3F is indicated in FIG. 3C. Duct 460 allows a tensioning strand inserted therein to apply tension through the shotcrete wall section to a corner post mounted at either end. Reinforcing steel dowels 310 can be embedded in the floor and tied into or bear against other reinforcements (not shown) in the shotcrete wall or the floor. Connecting groove 210 receives diaphragm panel 451 and seals it to the floor.

[0078] FIGS. 4A-4C illustrate plan, partial section, and perspective views of a concrete floor slab, diaphragm, L-shaped structural corner, and epoxy sealed waterstop for a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The location for FIG. 4B is indicated in FIG. 4A. A first diaphragm sheet (running down in FIG. 4A, towards the viewer in FIG. 4B, and angled to the right in FIG. 4C) is shown in each of FIGS. 4A-4C, respectively, but a second diaphragm sheet (running left in each of FIGS. 4A and 4B, respectively, and angled to the left in FIG. 4C) is shown in each of FIGS. 4A and 4B, respectively, but hidden for clarity in FIG. 4C. Open angle shaped corner post 410 includes first and second plates 420, each having a tension face 423 and a bearing face 421 defining direction 422. The first and second plates are connected by corner 424, and each respectively supports a tab connector 430 making connection 431 with diaphragm sheet 451. Barrel connector 462 holds tension strand 461 against tension face 423. In FIG. 4B, part of the floor is hidden to show the submerged portions of corner post 410, connecting groove 210, and diaphragm 451. While the outline of the floor and shotcrete walls are shown in FIG. 4A, the shotcrete is hidden and components are shown in a no hidden lines view for clarity.

[0079] FIGS. 4D-4F illustrate plan, partial section, and perspective views of a concrete floor slab, diaphragm, hollow box-shaped structural corner, and epoxy sealed waterstop for a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The location for FIG. 4E is indicated in FIG. 4D. A first diaphragm sheet (running down in FIG. 4D, towards the viewer in FIG. 4E, and angled to the right in FIG. 4F) is shown in each of FIGS. 4D-4F, respectively, but a second diaphragm sheet (running left in each of FIGS. 4D and 4E, respectively, and angled to the left in FIG. 4F) is shown in each of FIGS. 4D and 4E, respectively, but hidden for clarity in FIG. 4F. Closed box-section corner post 410 includes first and second plates 420, each having a tension face 423 and a bearing face 421 defining direction 422. The first and second plates are connected by corner 424 (and also by additional corners, plates, and structural members, not labelled), and each respectively supports a tab connector 430 making connection 431 with diaphragm sheet 451. Barrel connector 462 holds tension strand 461 against tension face 423. In FIG. 4E, part of the floor is hidden to show the submerged portions of corner post 410, connecting groove 210, and diaphragm 451. While the outline of the floor and shotcrete walls are shown in FIG. 4D, the shotcrete is hidden and components are shown in a no hidden lines view for clarity.

[0080] FIGS. 5A-5E illustrate perspective, plan, and detail views of a partially erected structure comprising four L-shaped structural corner members, eight T-shaped bisecting wall junctions, tensioning ducts, tensioning tendons, and barrel connectors prior to application of shotcrete, for a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The location for FIG. 5C is indicated in FIG. 5A. Certain diaphragm sheets, the outline of the floor slab, and the outline of the base of the tapered shotcrete walls are shown in FIG. 5B, but hidden for clarity in FIG. 5A and FIG. 5C, respectively. The floor (130, not visible) is hidden for clarity in FIG. 5A. FIG. 5D illustrates additional details from FIG. 5B, and FIG. 5E illustrates a detailed view of the area around one tab connector 430 as indicated in FIG. 5D. The full diaphragm 450 connecting two corner posts 410 along one wall in FIG. 5A contains a multiplicity of diaphragm sheets 451 and three bisecting wall junction plates 610, all running adjacent tensioning strands 461 running through tensioning ducts 460. Additional bisecting wall plates 610 are in place to support three primary and one secondary non-tensioned bisecting walls (matching the tank configuration shown in FIGS. 1A-2H.) Angles A-1 through A-6, radius R1, radius R2, tab connector width W, tab connector depth D, tab connector offset length L, and wall thickness T are each respectively shown in at least one of FIGS. 5B, 5D, and 5E. Although all angles are shown at 90 in FIGS. 5B, 5D, and 5E, any of these angles can be more or less than 90 (e.g., 30, 45, 60, 120, or 150 degrees or any angle from 0 to 360 degrees that is supported by the arrangement of the walls, corner posts, and related hardware to provide required clearances and alignments according to various embodiments of the subject invention. FIG. 5D shows radius R2 forming corner 424, angle A-6 between the plate and tab connector 430, tab depth d of tab connector 430, and tab width w of tab connector 430. While the outline of the floor and shotcrete walls are shown, the shotcrete is hidden and components are shown in a no hidden lines view for clarity. While angle A-6 is shown at 90 in FIG. 5D, it can be more or less than 90 (e.g., 30, 45, 60, 120, or 150 degrees or any angle from 0 to 360 degrees that is supported by the arrangement of the walls, corner post, tab connector, diaphragm sheet, and related hardware to provide required clearances and alignments for construction and post-tensioning of respective walls according to various embodiments of the subject invention.

[0081] FIGS. 6A-6E illustrate plan, perspective, and detail views of an erected structure for a non-reinforced bisecting wall junction (FIG. 6A) and a reinforced bisecting wall junction (FIG. 6B), each respectively comprising a T-shaped structural bisecting wall junction plate connected between first and second diaphragm sheets in the main wall and a third diaphragm sheet in the bisecting wall, assembled prior to application of shotcrete (e.g., as shown in FIGS. 6C-6E) and in a no-hidden-line view showing the finished top edges of the shotcrete wall (e.g., as shown in FIGS. 6A-6B) for a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The respective location for each of FIGS. 6D and 6E is indicated in FIG. 6C. A representative respective location for each of FIGS. 6A and 6B is indicated in FIG. 1A. Wall direction 622 is shown in FIG. 6A. Body 611 of bisecting wall plate 610 is indicated in FIG. 6C. FIG. 6E shows how tab connector 430 surrounds and supports seal 431. In FIG. 6F, weldable couplers 630 support reinforcing steel elements 310 and bisecting wall junction plate 610. While the outline of the floor and shotcrete walls are shown in FIGS. 6A and 6B, the shotcrete is hidden and components are shown in a no hidden lines view for clarity.

[0082] FIG. 7 illustrates a cutaway blackline view of a wall section for a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention. The full-depth shotcrete is cut away to show the internal structure of the wall. The provided persistent compression and fully encased steel shell diaphragm inhibit leaks that can otherwise occur due to water migration and allowable cracks. The depicted embodiment is constructed from durable and less porous high strength shotcrete whose long life with minimal maintenance is universally recognized throughout the water/wastewater industry. The provided turnkey design/build construction methodology delivers unsurpassed quality and reliability with the lowest life cycle cost available. The novel configuration that leverages reliable technology and proven process with no cold joints uniquely provided in a straight-wall tank through the combined performance of integral steel shell diaphragm with a homogenous, durable layer of shotcrete in constant compression along the straight walls, requiring no interior coatings to achieve persistent watertightness. Within the shotcrete core wall, mild steel reinforcements support a continuous steel shell diaphragm without horizontal joints, and the vertical joints between diaphragm sheets are sealed with epoxy injection after the steel shell has been encased with shotcrete. High strength strand is applied within the provided post-tensioning strand ducts and fully encased in a shotcrete overcoat and optional masonry paint system, to create persistent compression in the shotcrete core wall.

[0083] FIGS. 8A-8D schematically illustrate exemplary and non-limiting embodiments according to Embodiment 21 (FIG. 8A), Embodiment 22 (FIG. 8B), Embodiment 23 (FIG. 8C), and Embodiment 31 (FIG. 8D), each respectively according to an embodiment of the subject invention. FIGS. 8A-8D are schematic in nature, not to scale, exemplary and non-limiting. For example, unless otherwise specified the angles between wall, the length of walls, the number and placement of walls, corners, bisectors, bisecting junctions, and other elements can change.

[0084] In FIGS. 2C, 2D, 2G, 2H, 4C, 4F, and 6D the grooves (210) are represented with a black or finely hatched bottom surface to clarify the location of the grooves in these perspective views. In FIGS. 3C and 3D the cross section of the diaphragm sheet has been represented at the center of the respective groove or waterstop for clarity, while noting that corrugated diaphragm sheets can occupy various locations in the sealing groove, including by way of example but not limitation, following the zig-zag pattern illustrated in these figures.

Materials and Methods

[0085] All patents, patent applications, provisional applications, and publications referred to or cited herein are incorporated by reference in their entirety, including all figures and tables, to the extent they are not inconsistent with the explicit teachings of this specification.

[0086] Following are examples that illustrate procedures for practicing the invention. These examples should not be construed as limiting. All percentages are by weight and all solvent mixture proportions are by volume unless otherwise noted.

Example 1Commercial Justification for a Watertight Composite Straight Wall Post-Tensioned Concrete Tank Structure According to an Embodiment of the Subject Invention

[0087] A municipal wastewater processing facility in the state of Texas had a need for a 229,427 gallon tank in a 71 feet long, 27 feet wide, and 16 feet tall space. The design-build contractor had estimated a cost to provide a conventional (e.g., related art, cast in place rectangular) tank. The inventor proposed a watertight composite straight wall post-tensioned concrete tank structure according to an embodiment of the subject invention to provide superior performance and longevity at a similar cost.

Example 2Design and Analysis Framework for a Watertight Composite Straight Wall Post-Tensioned Concrete Tank Structure According to an Embodiment of the Subject Invention

A. Modeling & Analysis

[0088] 1. Flat plate Finite Element Analysis (FEA) physical model using Staad.Pro [0089] a. Develop the flat plate model using very fine mesh plate elements. [0090] b. Assign material properties in the flat plate. [0091] c. Define appropriate boundary conditions for three different analysis cases: [0092] i. Three sides fixed and top side free. [0093] ii. Three sides pinned and top side free. [0094] iii. Bottom side fixed, two sides pinned and top side free. [0095] d. Define support in the base plate (i.e., represent concrete floor slab in the model.) [0096] e. Apply hydrostatic loading. [0097] 2. Squared tank FEA model without post-tensioning using Staad.Pro Connect [0098] a. Develop the tank model using very fine mesh plate elements. [0099] b. Assign material properties in the tank model. [0100] c. Define appropriate boundary conditions. [0101] d. Define support in the tank base. [0102] e. Apply hydrostatic loading to the model. [0103] 3. Squared tank FEA model with post-tensioning using Staad.Pro Connect [0104] a. Develop the tank model using very fine mesh plate elements. [0105] b. Assign material properties in the tank model. [0106] c. Define appropriate boundary conditions. [0107] d. Define support in the tank base. [0108] e. Apply post-tensioning calculations for the tank walls. [0109] f. Apply hydrostatic loading and post-tensioning loading to the model. Before applying the post-tensioning loading, the model used released end rotation on the side of the wall.

B. Design

[0110] 1. Design tapered hydrostatic straight wall using ACI 350-20 Code Requirements for Environmental Engineering Concrete Structures [0111] a. Develop classical calculations to design the wall and compare moments and shears from Staad.Pro FEA model. [0112] b. Develop Post-Tensioning load calculations to be applied to the Staad.Pro FEA model. [0113] c. Check flexure and shear resteel requirements in the wall based on ACI 350-20. [0114] d. Check serviceability condition in the wall based on ACI 350-20. [0115] e. Check flexural and shear requirements at the wall footer due to direct tension and shrinkage and temperature based on ACI 350-20. [0116] 2. Design corner connection between straight walls. [0117] a. Design 1212 composite concrete filled square hollow structural section (HSS) including 1 dia. 316 SS tube stiffener placed inside of the HSS. A respective composite concrete filled square HSS will be used to connect each respective pair of two straight walls using the post-tensioning strands running through each respective wall and anchored in the corner structure. [0118] b. Check the composite HSS for flexure and shear due to the post-tensioning loading based on AISC 15.sup.th EditionChapter I.

Example 3Construction of a Prototype Watertight Composite Straight Wall Post-Tensioned Concrete Tank Structure According to an Embodiment of the Subject Invention

[0119] Construction of a watertight composite straight wall tendon-prestressed tank structure according to an exemplary but non-limiting rectangular embodiment of the subject invention is described herein. This embodiment comprises two parallel long external post-tensioned structural walls and two perpendicular short external post-tensioned structural walls, each respectively joined to the two adjacent walls by one of four 90 corners to form a rectangle and bisected to form additional sub-compartments within the rectangular tank, with three primary bisecting walls and one secondary bisecting wall, as shown in FIGS. 1A-1B.

[0120] We first perform a site layout and surveying with precision and accuracy in the control points. With the control points properly established, we proceed with fine-grading the subgrade for proper elevation, and then cast the working slabs to the proper dimensions and thickness. From there, the edge forms that will create the tank floor are laid out on top of the working slabs. With the working slabs and edge forms established, we tie the floor steel and corresponding wall dowels into the floor. Finally, the formwork is set that will later create in the floor the corner connection grooves (CCG) and wall connection grooves (WCG). The WCG will seal each of the diaphragm sheets and bisecting wall junction plates (where present), respectively, in each wall to the floor and the CCG will seal each corner post, respectively, to the floor and to the terminating diaphragm sheet in each respective wall. In this embodiment, a raw groove cast into the floor serves as the WCG and CCG and is filled directly with epoxy as provided below. In alternative embodiments, a waterstop element such as a pvc waterstop groove is cast into the floor, and the waterstop provides a groove to seal with the wall diaphragm, bisecting wall connector plates, and corner posts with the floor.

[0121] With the layout, surveying, working slabs, edge forms, and connection groove formwork complete, we cast the floor. Once the floor is cast and cured to optimal strength (e.g., by curing for 24-48 hours before proceeding to the next steps), we strip the groove formwork set the four corner posts into the CCG in the floor, making sure they are plumb. In this embodiment the corner posts and bisecting wall connector plates are set into the grooves in the floor after the floor has cured. In alternative embodiments, the corner posts and/or bisecting wall connector plates can be set into the floor during the casting process and set directly into the floor, either with or without additionally sealing.

[0122] The diaphragm is subsequently erected for the two long external walls, with each respective diaphragm sheet and bisecting wall junction plate (where present) set in the WCG, mechanically connected to adjacent sheet(s) or adjacent bisecting wall junction plate(s) for future epoxy injection, and secured into the tabs of each respective corner post to create a mechanical joint for future epoxy injection. From there, the diaphragm (including bisecting wall junction plate(s) (where present) and corner posts are sealed into the WCG in the floor with epoxy.

[0123] All horizontal seals with the floor (e.g., into the CCG and WCG) are made prior to the application of shotcrete on the walls, while all vertical seals above the floor (e.g., between the respective diaphragm sheets, corner posts, and bisecting wall junction plates) can be made later and protected during shotcrete application (e.g., by providing a specifically protected mechanical connection, by adding a protective element (e.g., tape) in or around the mechanical connection, and/or by providing specific steps or methods in the application of shotcrete) to provide and maintain each respective mechanical connection as needed to produce a useful epoxy seal at each respective joint (e.g., mechanical connections that are structurally sound to maintain designed seal dimensions and geometry, open and unobstructed to allow application of the sealant throughout, and free from construction debris, shotcrete, or other foreign material that can impair the seal.) An advantageous feature of certain embodiments of the subject invention, including the embodiment in this example, is the absence of horizontal joints above the floor, which can allow access to all remaining (vertical) joints for sealing from above after application of shotcrete. In alternative embodiments, one or more horizontal joints (e.g., either in the floor, above the floor, or below the floor) can be sealed after application of shotcrete. In alternative embodiments, one or more vertical joints (e.g., either in the floor, walls, or corners) can be sealed before application of shotcrete.

[0124] With the diaphragm for the two long external walls in place and sealed to the floor, an initial layer of wall reinforcing steel is positioned and tied on the exterior side of each respective diaphragm, creating the first layer of the outer wall steel. Once the wall reinforcing steel is positioned correctly and tied, shotcrete is applied in thin successive layers until the first layer of reinforcing steel is fully encapsulated, forming a first layer of reinforced shotcrete. Next, the post-tensioning ducts are positioned and connected to each respective corner post for the two long external walls, the remaining outside vertical steel is placed and tied outside of the post-tensioning ducts, and then shotcrete is applied in thin successive layers until all outside components for the two long external walls are fully encapsulated, forming a second layer of reinforced shotcrete. With the outside of the two long external walls complete, we now move inside the structure. We place and tie the reinforcing steel on the inside face of the diaphragm and bisecting wall junction plate(s) (where present) for the two long external walls and then shotcrete is applied in thin successive layers to fully encapsulate the diaphragm, the first portion of each respective bisecting wall junction plate (i.e., the top portion of the T directly connecting respective diaphragm sheets within the two long external walls, but not the shaft of the T that will connect to the diaphragm in each respective bisecting wall), and reinforcing steel on the inside of the two long external walls.

[0125] With the two long external walls constructed, we build the outside of one of the two perpendicular short external end walls and the center primary bisecting wall in parallel, following the method above. In this embodiment, the bisecting walls are not post-tensioned and do not require post-tensioning ducts. With three external walls and one primary bisecting wall constructed, we build the two additional primary bisecting walls and one secondary bisecting wall between them, following the method above. After all interior bisecting walls are constructed, we complete construction of the second perpendicular short exterior end wall. In alternative embodiments, different order and sequencing of wall construction are contemplated within the scope of the subject invention.

[0126] The final steps begin with epoxy sealing of each respective vertical joint between sheets of diaphragm, bisecting wall junction plates, and corner post tab connectors with epoxy injection. While epoxy sealants are referenced herein, suitable alternative sealers known in the art, or as may be later invented, developed, or discovered are contemplated within the scope of the subject invention. While galvanized steel sheet metal diaphragm sheets are referenced herein, suitable alternative materials and/or configurations known in the art, or as may be later invented, developed, or discovered are contemplated within the scope of the subject invention. Next, with proper concrete strength gain verified, we prepare for post-tensioning by inserting and threading through each respective post-tensioning duct a respective post-tensioning tendon with barrel bolts at either end, bearing on the respective corner post. We then post-tension all four external walls, according to methods known in the art. Finally, all external surfaces receive a smooth homogenous cover coat of shotcrete providing minimum coverage requirements and a joint-free surface.

[0127] When performed as described, this process produces a watertight and durable composite straight wall post-tensioned tank structure according to an exemplary but non-limiting embodiment of the subject invention, providing unsurpassed longevity and value compared to related art systems and methods.

[0128] The primary bisecting walls (between two post-tensioned, e.g., exterior walls) and secondary bisecting walls (between two non-tensioned, e.g., interior walls) provided in the preceding embodiment are optional in certain other embodiments of the subject invention. Bisecting walls (either primary or secondary) can advantageously provide additional value and benefits including added functionality of sub-compartments (e.g., one or more aeration, membrane bioreactor (MBR), anoxic, and/or equalization (EQ) basins) beneficially supporting water treatment system requirements at an affordable cost, with high reliability, and with efficient space utilization, according to certain embodiments, including the one described above in this Example. Other embodiments can advantageously provide more, fewer, or even no bisecting walls and sub-compartments, providing flexibility in design and construction of certain embodiments to meet specific needs in various commercially relevant applications.

[0129] It is contemplated within the scope of the subject invention that embodiments can provide a mix of orthogonal and non-orthogonal angles. It is contemplated within the scope of the subject invention that embodiments can provide a mix of post-tensioned and non-tensioned walls, corner posts, and/or bisecting wall connectors. It is contemplated within the scope of the subject invention that embodiments can provide either non-reinforced bisecting wall connectors (e.g., as shown in FIG. 6A) or reinforced bisecting wall connectors (e.g., as shown in FIG. 6B) at either internal or external bisecting wall junctions as needed to meet design loads.

EXEMPLIFIED EMBODIMENTS

[0130] The invention may be better understood by reference to certain illustrative examples, including but not limited to the following:

[0131] Embodiment 1. A tensioning system providing structural support, watertight sealing, and post-tensioning for a straight-wall concrete tank (100), the system comprising: [0132] a corner post (410) comprising: [0133] a first plate (420) comprising a first bearing surface (421) defining a first direction (422) and an opposite first tensioning surface (423), [0134] a second plate (420) comprising a second bearing surface (421) defining a second direction (422) and an opposite second tensioning surface (423), [0135] a corner (424) formed where the first plate (420) is fixedly attached to the second plate (420), [0136] a first tab connector (430), fixedly attached to and extending from the first plate (420), configured to support a first diaphragm seal (431) with a diaphragm sheet (451) that is oriented substantially in the first direction (422), and [0137] a second tab connector (430) fixedly attached to and extending from the second plate (420), configured to support a second diaphragm seal (431) with a diaphragm sheet (451) that is oriented substantially in the second direction (422); [0138] the corner post (410) receiving a first persistent tensile load in the first direction (422) and a second persistent tensile load in the second direction (422); [0139] the corner post (410) providing structural support for a first persistent compressive load in the first direction and a second persistent compressive load in the second direction; and [0140] the corner post (410) providing a persistent watertight connection between the first tab connector (430) and the second tab connector (430).

[0141] Embodiment 2. The system according to Embodiment 1, wherein the corner post (410) is a first corner post (410), the system comprising a first multiplicity of tensioning strands (461) configured and adapted to carry the first persistent tensile load in the first direction (422) between the first corner post (410) and a second corner post (410).

[0142] Embodiment 3. The system according to Embodiment 2, comprising: [0143] a first multiplicity of diaphragm sheets (450) each, respectively, substantially aligned with the first direction (422) and configured to create a persistent watertight seal between the first corner post (410) and the second corner post (410).

[0144] Embodiment 4. The system according to Embodiment 3, comprising: [0145] a second multiplicity of tensioning strands (461) configured and adapted to carry the second persistent tensile load in the second direction (422) between the first corner post (410) and a third corner post (410); and [0146] a second multiplicity of diaphragm sheets (450) each, respectively, substantially aligned with the second direction (422) and configured to create a persistent watertight seal between the first corner post (410) and the third corner post (410).

[0147] Embodiment 5. The system according to Embodiment 4, comprising: [0148] a third multiplicity of tensioning strands (461) configured and adapted to carry a third persistent tensile load in a third direction (422) between the second corner post (410) and the third corner post (410); and [0149] a third multiplicity of diaphragm sheets (450) each, respectively, substantially aligned with the third direction (422) and configured to create a persistent watertight seal between the second corner post (410) and the third corner post (410).

[0150] Embodiment 6. The system according to Embodiment 4, comprising: [0151] a third multiplicity of tensioning strands (461) configured and adapted to carry a third persistent tensile load in a third direction (422) between the second corner post (410) and a fourth corner post (410); [0152] a third multiplicity of diaphragm sheets (450) each, respectively, substantially aligned with the third direction (422) and configured to create a persistent watertight seal between the second corner post (410) and the fourth corner post (410); [0153] a fourth multiplicity of tensioning strands (461) configured and adapted to carry a fourth persistent tensile load in a fourth direction (422) between the third corner post (410) and the fourth corner post (410); and [0154] a fourth multiplicity of diaphragm sheets (450) each, respectively, substantially aligned with the fourth direction (422) and configured to create a persistent watertight seal between the third corner post (410) and the fourth corner post (410).

[0155] Embodiment 7. The system according to Embodiment 6, comprising: [0156] a first bisecting wall junction plate (610) connecting two respective diaphragm sheets (450) of the second multiplicity of diaphragm sheets (450); [0157] a second bisecting wall junction plate (610) connecting two respective diaphragm sheets (450) of the third multiplicity of diaphragm sheets (450); and [0158] a fifth multiplicity of diaphragm sheets (450) each, respectively, substantially aligned with a fifth direction between the first bisecting wall junction plate (610) and the second bisecting wall junction plate (610) and configured to create a persistent watertight seal between the first bisecting wall junction plate (610) and the second bisecting wall junction plate (610).

[0159] Embodiment 8. The system according to Embodiment 7, comprising: [0160] a third bisecting wall junction plate (610) connecting two respective diaphragm sheets (450) of the second multiplicity of diaphragm sheets (450); [0161] a fourth bisecting wall junction plate (610) connecting two respective diaphragm sheets (450) of the third multiplicity of diaphragm sheets (450); [0162] a sixth multiplicity of diaphragm sheets (450) each, respectively, substantially aligned with a sixth direction between the third bisecting wall junction plate (610) and the fourth bisecting wall junction plate (610) and configured to create a persistent watertight seal between the third bisecting wall junction plate (610) and the fourth bisecting wall junction plate (610); [0163] a fifth bisecting wall junction plate (610) connecting two respective diaphragm sheets (450) of the fifth multiplicity of diaphragm sheets (450); [0164] a sixth bisecting wall junction plate (610) connecting two respective diaphragm sheets (450) of the sixth multiplicity of diaphragm sheets (450); and [0165] a seventh multiplicity of diaphragm sheets (450) each, respectively, substantially aligned with a seventh direction between the fifth bisecting wall junction plate (610) and the sixth bisecting wall junction plate (610) and configured to create a persistent watertight seal between the fifth bisecting wall junction plate (610) and the sixth bisecting wall junction plate (610)).

[0166] Embodiment 9. The system according to Embodiment 2, the first corner post (410) comprising an extruded, formed, or rolled steel section and one or more weldments added thereto; the one or more weldments forming at least a portion of the first tab connector (430) and at least a portion of the second tab connector (430); the one or more weldments comprising one or more members selected from the list comprising: flat stock, angle stock, C-channel, rod, tube, or box-section steel.

[0167] Embodiment 10. The system according to Embodiment 9, the first corner post (410) comprising a taper from a wider base dimension to a narrower top dimension.

[0168] Embodiment 11. The system according to Embodiment 10, the first plate (420) comprising a first multiplicity of holes (425) configured to receive the first multiplicity of tensioning strands (461) carrying the first persistent tensile load in the first direction (422); and [0169] the second plate (420) comprising a second multiplicity of holes (425) configured and adapted to receive a second multiplicity of tensioning strands (461) carrying the second persistent tensile load in the second direction (422).

[0170] Embodiment 12. The system according to Embodiment 7, first bisecting wall junction plate (610) comprising: [0171] a body (611); [0172] a third tab connector (430) fixedly attached to and extending from the body (611), the third tab connector (430) configured to support a first diaphragm seal (431) with a diaphragm sheet (451) that is oriented substantially in a primary wall direction (622); [0173] a fourth tab connector (430) fixedly attached to and extending from the body (611), the fourth tab connector (430) configured to support a second diaphragm seal (431) with a diaphragm sheet (451) that is oriented substantially opposite the primary wall direction (622); and [0174] a fifth tab connector (430) fixedly attached to and extending from the body (611), the fifth tab connector (430) configured to support a third diaphragm seal (431) with a diaphragm (450) that is substantially oriented with a secondary wall angle that is at an angle to the primary wall direction (622).

[0175] Embodiment 13. The system according to Embodiment 12, wherein the body comprises a T cross section.

[0176] Embodiment 14. The system according to Embodiment 12, wherein the body comprises at least one cross section selected from the group consisting of a polygonal cross section, an oval cross section, and a round cross section.

[0177] Embodiment 15. The system according to any preceding Embodiment, comprising: [0178] a first post-tensioned shotcrete wall bearing against the first bearing surface (421) and substantially aligned with the first direction (422); and [0179] a second post-tensioned shotcrete wall bearing against the second bearing surface (421) and substantially aligned with the second direction (422).

[0180] Embodiment 16. The system according to any preceding Embodiment, comprising: [0181] a cast in place (CIP) concrete floor (130) comprising one or more connection grooves (210) configured and adapted to receive at least the first multiplicity of diaphragm sheets (450) and provide a persistent watertight seal therewith.

[0182] Embodiment 17. A method for constructing a watertight and durable composite straight wall post-tensioned tank structure at a construction site, the method comprising: [0183] a) performing a site layout and surveying to establish sufficient precision and accuracy in a set of control points at the construction site; [0184] b) fine-grading a subgrade for proper elevation with respect to the set of control points; [0185] c) casting a set of working slabs on the subgrade and laying out edge forms thereon for a tank floor; [0186] d) setting floor steel and corresponding wall dowels within the edge forms; [0187] e) setting a groove formwork to create in the floor one or more corner connection grooves (CCG) and one or more wall connection grooves (WCG); [0188] f) casting concrete within the edge forms to create a floor comprising the CCG and WCG; [0189] g) allowing the floor to cure at least 12 hours to achieve a predetermined strength; h) stripping the groove formwork; [0190] i) setting a set of four corner posts into the CCG in the floor; [0191] j) confirming alignment, position, and plumb of each respective corner post; [0192] k) sealing each respective corner post into the CCG in the floor; [0193] l) erecting a multiplicity of diaphragm sheets and bisecting wall junction plates to form a respective diaphragm in each of two long, straight, external walls, with each respective diaphragm sheet and bisecting wall junction plate set in the WCG, mechanically connected to adjacent diaphragm sheet(s) or adjacent bisecting wall junction plate(s), or secured into a respective tab connector of each respective corner post to create a mechanical joint for future epoxy injection; [0194] m) sealing each respective diaphragm sheet, bisecting wall junction plate, and corner post into the WCG in the floor; [0195] n) positioning and tying a first layer of wall reinforcing steel on an exterior side of each respective diaphragm, to create a first layer of outer wall reinforcing steel; [0196] o) applying shotcrete in thin successive layers until the first layer of outer wall reinforcing steel is fully encapsulated between respective bearing surfaces of the respective corner posts at each end of each respective outer wall, forming a first outer layer of reinforced shotcrete; [0197] p) positioning a multiplicity of post-tensioning ducts and connecting a respective end of each duct to a respective corner post for each of the two long, straight, external walls; [0198] q) positioning and tying a second layer of wall reinforcing steel outside of the post-tensioning ducts, to create a second layer of outer wall reinforcing steel; [0199] r) applying shotcrete in thin successive layers until all outside components for the two long external walls are fully encapsulated between respective bearing surfaces of the respective corner posts at each end of each respective outer wall, forming a second layer of reinforced shotcrete; [0200] s) positioning and tying a third layer of wall reinforcing steel on the inside face of the diaphragm and bisecting wall junction plates for the two long external walls; and [0201] t) applying shotcrete in thin successive layers until the diaphragm, the top portion of the T directly connecting respective diaphragm sheets within the two long external walls of each respective bisecting wall junction plate, but not the shaft of the T that will connect to the diaphragm in each respective bisecting wall, and the third layer of wall reinforcing steel on the inside face of the diaphragm and bisecting wall junction plates are fully encapsulated between respective bearing surfaces of the respective corner posts at each end of each respective outer wall, forming a third layer of reinforced shotcrete to substantially complete the concrete structure of the two long external walls.

[0202] Embodiment 18. The method according to Embodiment 17, comprising: [0203] u) building a first one of two perpendicular short external end walls and a center primary bisecting wall, following the steps (l) through (t), omitting bisecting wall junction plate(s) and tensioning ducts where not required; [0204] v) building two additional primary bisecting walls and one secondary bisecting wall therebetween, following the steps (l) through (t), omitting tensioning ducts where not required; and [0205] w) building a second one of two perpendicular short external end walls, following the steps (l) through (t), bisecting wall junction plate(s) and tensioning ducts where not required.

[0206] Embodiment 19. The method according to Embodiment 18, comprising: [0207] x) epoxy sealing each respective vertical joint formed between each respective diaphragm sheet, bisecting wall junction plate, and corner post tab connector with epoxy injection; [0208] y) verifying proper concrete strength gain in at least one wall; [0209] z) inserting and threading through each respective post-tensioning duct a respective post-tensioning strand and attaching barrel bolts thereto at each respective end, bearing on each respective corner post; [0210] aa) post-tensioning all four external walls; and [0211] bb) after post-tensioning all four external walls, applying shotcrete in thin successive layers on and between respective tensioning surfaces of the respective corner posts at each end of each respective outer wall until the first layer of outer wall reinforcing steel is fully encapsulated, forming a first outer layer of reinforced shotcrete.

[0212] Embodiment 20. The method according to Embodiment 19, comprising: [0213] cc) applying shotcrete to each external surface formed in the preceding steps, to create a smooth homogenous cover coat of shotcrete providing minimum coverage requirements and a joint-free surface, to produce the watertight and durable composite straight wall post-tensioned tank structure.

[0214] Embodiment 21. A persistent watertight post-tensioned concrete composite straight wall tank (100) comprising: [0215] a first persistent watertight post-tensioned concrete composite corner (110); [0216] a second persistent watertight post-tensioned concrete composite corner (110); [0217] a third persistent watertight post-tensioned concrete composite corner (110); [0218] a first persistent watertight post-tensioned concrete composite straight wall (120) connecting the first corner (110) and the second corner (110); [0219] a second persistent watertight post-tensioned concrete composite straight wall (120) connecting the second corner (110) and the third corner (110); [0220] a third persistent watertight post-tensioned concrete composite straight wall (120) connecting to the first corner (110); and [0221] a persistent watertight cast in place (CIP) concrete composite floor (130) comprising one or more connection grooves (210) aligned respectively with each of the first corner (110), the second corner (110), and the third corner (110), and one or more wall connection grooves (210) aligned respectively with each of the first wall (120), the second wall (120), and the third wall (120).

[0222] Embodiment 22. The persistent watertight post-tensioned concrete composite straight wall tank (100) according to Embodiment 21, the third wall (120) connecting the first corner (110) and the third corner (110) to form a triangular tank (100).

[0223] Embodiment 23. The persistent watertight post-tensioned concrete composite straight wall tank (100) according to Embodiment 21, comprising: [0224] a fourth persistent watertight post-tensioned concrete composite corner (110); and [0225] a fourth persistent watertight post-tensioned concrete composite straight wall (120) connecting the third corner (110) and the fourth corner (110); [0226] the third wall (120) connecting the first corner (110) and the fourth corner (110); and [0227] the fourth wall (120) connecting the fourth corner (110) and the third corner (110) to form a quadrilateral tank (100); and [0228] the floor (130) comprising one or more connection grooves (210) aligned respectively with each of the each of the fourth corner (110), and the fourth wall (120).

[0229] Embodiment 24. The persistent watertight post-tensioned concrete composite straight wall tank (100) according to Embodiment 23, wherein the third wall (120) forms a first corner angle (A-3) relative to the first wall (120) at the first corner (110) and the second wall (120) forms a second corner angle (A-3) relative to the first wall (120) at the second corner (110); the first corner angle (A-3) and the second corner angle (A-3) each respectively being substantially equal to 90. The corner angle (A-3) can be measured between the designed or actual axis or line of pull of the respective tension strands in the first and second walls respectively. Alternatively, the corner angle can be measured in certain embodiments as A-1, A-2, or A-4 as shown in FIG. 5B, or as any measurable angle between two walls meeting at a corner.

[0230] Embodiment 25. The persistent watertight post-tensioned concrete composite straight wall tank (100) according to Embodiment 24, wherein the fourth wall (120) forms a third corner angle (A-3) relative to the second wall (120) at the third corner (110) and the fourth wall (120) forms a fourth corner angle (A-3) relative to the third wall (120) at the fourth corner (110); the third corner angle (A-3) and the fourth corner angle (A-3) each respectively being substantially equal to 90, thus forming a square or rectangular tank.

[0231] Embodiment 26. The persistent watertight post-tensioned concrete composite straight wall tank (100) according to Embodiment 24, wherein the fourth wall (120) forms a third corner angle (A-3) relative to the second wall (120) at the third corner (110) and the fourth wall (120) forms a fourth corner angle (A-3) relative to the third wall (120) at the fourth corner (110); the third corner angle (A-3) being greater than 90; and the fourth corner angle (A-3) being less than 90, thus forming an irregular four-sided polygonal tank.

[0232] Embodiment 27. The persistent watertight post-tensioned concrete composite straight wall tank (100) according to Embodiment 23, comprising: [0233] a total of n persistent watertight post-tensioned concrete corners (110), where n is a positive integer greater than or equal to 3; and [0234] a total of n persistent watertight post-tensioned concrete composite straight walls (120); [0235] each wall (120) respectively connecting a respective corner (110) with exactly one other corner (110); [0236] each corner (110) respectively connecting a respective wall (120) with exactly one other wall (120) to form a closed and non-intersecting n-dimensional polygonal tank (100); and [0237] the floor (130) being configured and adapted to support a persistent watertight seal between the floor (130) and each respective wall (120) and corner (110).

[0238] Embodiment 28. The persistent watertight post-tensioned concrete composite straight wall tank (100) according to Embodiment 21, comprising: [0239] a first internal diaphragm (450) encased substantially within the post-tensioned concrete of the first wall (120); [0240] a second internal diaphragm (450) encased substantially within the post-tensioned concrete of the second wall (120); and [0241] a third internal diaphragm (450) encased substantially within the post-tensioned concrete of the third wall (120); [0242] one or more of the connection grooves (210) in the floor (130) aligned respectively with, and configured and adapted to receive and support a seal to a portion of each of the first internal diaphragm (450), the second internal diaphragm (450), and the third internal diaphragm (450), respectively.

[0243] Embodiment 29. The persistent watertight post-tensioned concrete composite straight wall tank (100) according to Embodiment 28, wherein each respective diaphragm (450) comprises a multiplicity of diaphragm sheets joined together with persistent watertight seals.

[0244] Embodiment 30. The persistent watertight post-tensioned concrete composite straight wall tank (100) according to Embodiment 28, comprising: [0245] a first sealed and loaded corner post (410) forming a portion of the first corner (110) and configured and adapted to: [0246] provide persistent post-tension to the first wall (120), [0247] provide persistent post-tension to the third wall (120), [0248] support a persistent seal with the first internal diaphragm (450), and [0249] support a persistent seal with the third internal diaphragm (450); [0250] the floor (130) comprising one or more connection grooves (211) each respectively configured and adapted to receive therein and support a respective persistent seal with the first sealed and loaded corner post (410).

[0251] Embodiment 31. The persistent watertight post-tensioned concrete composite straight wall tank (100) according to Embodiment 21, comprising: [0252] a first persistent watertight concrete bisecting junction (140); [0253] a second persistent watertight concrete bisecting junction (140); and [0254] a first persistent watertight concrete composite straight bisector (160) connecting the first bisecting junction (140) and the second bisecting junction (140), the first bisector (160) substantially encasing a first bisecting diaphragm (410) therein; [0255] the first bisecting junction (140) comprising a first bisecting junction plate (610) encased substantially within and forming a connection between the second wall (120) and the first bisector (160); [0256] the second bisecting junction (140) comprising a second bisecting junction plate (610) encased substantially within and forming a connection between the third wall (120) and the first bisector (160); [0257] the floor (130) comprising one or more connection grooves (210) each respectively configured and adapted to receive therein and support a respective persistent epoxy seal with the first bisecting diaphragm (410), the first bisecting junction plate (610), and the second bisecting junction plate (610).

[0258] Embodiment 32. The persistent watertight post-tensioned concrete composite straight wall tank (100) according to Embodiment 31, comprising: [0259] a third persistent watertight concrete bisecting junction (140); [0260] a fourth persistent watertight concrete bisecting junction (140); [0261] a fifth persistent watertight concrete bisecting junction (140); [0262] a sixth persistent watertight concrete bisecting junction (140); [0263] a second persistent watertight concrete composite straight bisector (160) connecting the third bisecting junction (140) and the fourth bisecting junction (140), the second bisector (160) substantially encasing a second bisecting diaphragm (410) therein; and [0264] a third persistent watertight concrete composite straight bisector (160) connecting the fifth bisecting junction (140) and the sixth bisecting junction (140), the third bisector (160) substantially encasing a third bisecting diaphragm (410) therein; [0265] the third bisecting junction (140) comprising a third bisecting junction plate (610) encased substantially within and forming a connection between the second wall (120) and the first bisector (160); [0266] the fourth bisecting junction (140) comprising a fourth bisecting junction plate (610) encased substantially within and forming a connection between the third wall (120) and the first bisector (160); [0267] the fifth bisecting junction (140) comprising a fifth bisecting junction plate (610) encased substantially within and forming a connection between the first bisector (160) and the second bisector (160); [0268] the sixth bisecting junction (140) comprising a sixth bisecting junction plate (610) encased substantially within and forming a connection between the first bisector (160) and the second bisector (160); [0269] the floor (130) comprising one or more connection grooves (210) each respectively configured and adapted to receive therein and support a respective persistent epoxy seal with the second bisecting diaphragm (410), the third bisecting diaphragm (410), the third bisecting junction plate (610), the fourth bisecting junction plate (610), the fifth bisecting junction plate (610), and the sixth bisecting junction plate (610).

[0270] Embodiment 33. The persistent watertight post-tensioned concrete composite straight wall tank (100) according to Embodiment 32, comprising: [0271] a seventh persistent watertight concrete bisecting junction (140); [0272] an eighth persistent watertight concrete bisecting junction (140); and [0273] a fourth persistent watertight concrete composite straight bisector (160) connecting the seventh bisecting junction (140) and the eighth bisecting junction (140), the fourth bisector (160) substantially encasing a fourth bisecting diaphragm (410) therein; [0274] the seventh bisecting junction (140) comprising a seventh bisecting junction plate (610) encased substantially within and forming a connection between the second wall (120) and the fourth bisector (160); [0275] the second bisecting junction (140) comprising an eighth bisecting junction plate (610) encased substantially within and forming a connection between the third wall (120) and the fourth bisector (160); [0276] the floor (130) comprising one or more connection grooves (210) each respectively configured and adapted to receive therein and support a respective persistent epoxy seal with the fourth bisecting diaphragm (410), the seventh bisecting junction plate (610), and the eighth bisecting junction plate (610).

[0277] Embodiment 34. The persistent watertight post-tensioned concrete composite straight wall tank (100) according to Embodiment 21, comprising: [0278] a first plurality of post-tensioning ducts (460) encased within the first wall (120) and connected at opposing ends between the first corner (110) and the second corner (110), each respective duct (460) of the first plurality of ducts (460) covering at least one respective strand (461) of a first plurality of post-tensioning strands (461) configured and adapted to carry a first tensile load between the first corner (110) and the second corner (110); and [0279] a second plurality of post-tensioning ducts (460) encased within the second wall (120) and connected at opposing ends between the second corner (110) and the third corner (110), each respective duct (460) of the second plurality of ducts (460) covering at least one respective strand (461) of a second plurality of post-tensioning strands (461) configured and adapted to carry a second tensile load between the second corner (110) and the third corner (110); [0280] wherein the first corner (110) and the second corner (110) are configured and adapted to bear the first tensile load and transfer the first tensile load into a first persistent compression in the first wall; and [0281] wherein the second corner (110) and the third corner (110) are configured and adapted to bear the second tensile load and transfer the second tensile load into a second persistent compression in the second wall.

[0282] Embodiment 35. The persistent watertight post-tensioned concrete composite straight wall tank (100) according to any of Embodiment 21-34, having a liquid storage capacity between 15,000 gallons and 1.5 million gallons, a wall height greater than 15 feet, and a measured leakage of less than 0.05% per day, based on volume.

[0283] Embodiment 36. A sealed and loaded corner post (410) useful for providing concurrent structural support, post-tensioning, and watertight sealing, the sealed and loaded corner post (410) comprising: [0284] a first bearing surface (421) defining a first direction (422) effectively normal thereto, the first bearing surface (421) configured and adapted to transmit a first persistent compressive load oriented substantially in the first direction (422); [0285] a second bearing surface (421) defining a second direction (422) effectively normal thereto, the second bearing surface (421) configured and adapted to transmit a second persistent compressive load oriented substantially in the second direction (422), the second direction (422) separated from the first direction (422) by a corner angle (A-3); [0286] a first tab connector (430) configured and adapted to support a first persistent watertight diaphragm seal (431) with a diaphragm sheet (451) that is oriented substantially in the first direction (422); and [0287] a second tab connector (430) configured and adapted to support a second persistent watertight diaphragm seal (431) with a diaphragm sheet (451) that is oriented substantially in the second direction (422); [0288] the sealed and loaded corner post (410) configured and adapted to provide structural support for the first persistent compressive load and the second persistent compressive load; and [0289] the sealed and loaded corner post (410) configured and adapted to provide a persistent watertight connection between the first tab connector (430) and the second tab connector (430).

[0290] Embodiment 37. The sealed and loaded corner post (410) according to Embodiment 36, comprising: [0291] a third bearing surface (421) defining a third direction (422) effectively normal thereto, the third bearing surface (421) configured and adapted to transmit a third persistent compressive load oriented substantially in the second direction (422), the corner angle (A-3) being a first corner angle (A-3), and the third direction (422) separated from the first direction (422) by a second corner angle (A-3); and [0292] a third tab connector (430) configured and adapted to support a third persistent watertight diaphragm seal (431) with a diaphragm sheet (451) that is oriented substantially in the third direction (422); [0293] the sealed and loaded corner post (410) configured and adapted to provide structural support for the third persistent compressive load; and [0294] the sealed and loaded corner post (410) configured and adapted to provide a persistent watertight connection between the first tab connector (430) and the third tab connector (430), and between the third tab connector (430) and the second tab connector (430).

[0295] Embodiment 38. A persistent watertight concrete bisecting junction (140) useful in the construction of a persistent watertight post-tensioned concrete composite straight wall tank (100), the persistent watertight concrete bisecting junction (140) comprising: [0296] a first straight concrete wall (120) substantially oriented in a first direction, the first wall (120) encasing a first diaphragm sheet (451) and a second diaphragm sheet (451); [0297] a second straight concrete wall (160) bisecting the first wall (120) and forming a corner angle (A-3) therebetween, the second wall (160) encasing a third diaphragm sheet (451); [0298] a bisecting junction plate (610) encased substantially within and forming a structural connection between the first wall (120) and the second wall (160), bisecting junction plate (610) connected to and forming a respective persistent watertight seal with each of the first diaphragm sheet (451), the second diaphragm sheet (451), and the third diaphragm sheet (451), respectively; and [0299] a floor (130) supporting each of the first wall (120), the second wall (120), and the bisecting junction plate (610), the floor (130) comprising one or more connection grooves (210) each respectively configured and adapted to receive a respective portion therein and support a respective persistent watertight seal with each of the bisecting junction plate (610), the first diaphragm sheet (451), the second diaphragm sheet (451), and the third diaphragm sheet (451), respectively.

[0300] Although the present invention has been illustrated and described herein with reference to preferred embodiments and specific examples thereof, it will be readily apparent to those of ordinary skill in the art that other embodiments and examples may perform similar functions and/or achieve like results.

[0301] It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and the scope of the appended claims. In addition, any elements or limitations of any invention or embodiment thereof disclosed herein can be combined with any and/or all other elements or limitations (individually or in any combination) or any other invention or embodiment thereof disclosed herein, and all such combinations are contemplated with the scope of the invention without limitation thereto.