Abstract
Foundation, apparatus and method for stabilization of a foundation. The foundation comprises a subsoil and a pavement structure formed over it, which pavement structure includes a plurality of successive structural layers. At least one of these structural layers is a binder-stabilized structural layer which includes stone materialand a binder. Additionally, the stabilized structural layer is enclosed within a sleeve structure.
Claims
1. A foundation, comprising: a subsoil; a pavement structure formed over the subsoil and comprising a plurality of successive structural layers; and wherein at least one of said structural layers is stabilized by means of at least one hardenable binder and forms a binder-stabilization layer; and further, wherein at least one of said binder-stabilization layers of the pavement structure is enclosed within a sleeve structure; wherein the binder-stabilization layer arranged inside the sleeve structure is of a geopolymer or an alkali-activatable hardenable mixture; and wherein the compression strength of the binder-stabilization layer arranged inside the sleeve structure is at least 0.1 Mpa.
2. The foundation according to claim 1, wherein: the binder-stabilization layer arranged inside the sleeve structure comprises stone material and at least one hardenable binder.
3. The foundation according to claim 1, wherein: the binder-stabilization layer arranged inside the sleeve structure comprises at least one fibre reinforcement.
4. The foundation according to claim 1, wherein the binder-stabilization layer arranged inside the sleeve structure is foamed.
5. The foundation according to claim 1, wherein the binder-stabilization layer arranged inside the sleeve structure further comprises at least one filler which is non-stone material.
6. The foundation according to claim 1, wherein the binder-stabilization layer arranged inside the sleeve structure further comprises at least one stiffener element.
7. The foundation according to claim 1, wherein the sleeve structure is flexible film-like material.
8. The foundation according to claim 1, wherein the sleeve structure is impermeable to liquid and solid material.
9. The foundation according to claim 1, wherein the sleeve structure comprises at least one reinforcement.
10. The foundation according to claim 1, wherein a cross-section of the sleeve structure as seen in a transverse direction of the foundation comprises at least one profiled portion which has a corrugated shape comprising alternating ridges and grooves.
11. The foundation according to claim 2, wherein the sleeve structure comprises two superposed films extending in a longitudinal direction of the foundation, the longitudinal edges of which films are closed and between which films the material treated with a hardenable binder is arranged.
12. The foundation according to claim 11, wherein the sleeve structure comprises a film extending in the longitudinal direction of the foundation,longitudinal edges of which film are folded together and fixed to each other, whereby a tubular shape having a closed cross-section is formed.
13. The foundation according to claim 1 - 12, wherein the sleeve structure is a seamless tube.
14. The foundation according to claim 1, wherein the sleeve structure comprises a separate lower film and upper film which delimit together a space for the binder-stabilization layer, and wherein the upper film is arranged to extend wider than the lower film in a transverse direction of the foundation, whereby both longitudinal edges of the upper film comprise wings.
15. The foundation according to claim 10, wherein an upper surface of the sleeve structure is a flat plane.
16. The foundation according to claim 15, wherein the cross-section of the upper surface of the sleeve structure is curved as seen in a longitudinal direction of the foundation slopes towards both longitudinal edges of the foundation.
17. The foundation according to claim 1, wherein the sleeve structure and the binder-stabilization layer arranged inside it extends as a unitary structure over the whole width of the foundation, whereby its width corresponds to the width of the foundation.
18. The foundation according to claim 1, wherein the foundation comprises at least two binder-stabilization layers arranged inside a sleeve structure.
19. The foundation according to claim 1, wherein the foundation is a road structure; and each longitudinal edge of the road structure comprises a road edge portion and that at least one edge portion comprises at least one binder-stabilization layer arranged inside the sleeve structure.
20. The foundation according to claim 1, wherein the sleeve structure or the binder-stabilization layer arranged inside it is provided with at least one cable.
21. The foundation according to claim 1, wherein the sleeve structure or the binder-stabilization layer arranged inside it is provided with at least one measuring device.
22. The foundation according to claim 1, wherein the binder-stabilization layer arranged in a space delimited by the sleeve structure is electrically conductive and is arranged to function as such as an electrical conductor.
23. The foundation according to claim 1, wherein the binder-stabilization layer arranged in a space delimited by the sleeve structure is electrically conductive and is arranged to function as an electricity storing element.
24. An apparatus for treating a structural layer of a foundation, which apparatus is a movable vehicle and comprises: at least one first feeding device for feeding at least one film-like sleeve structure to the foundation; at least one second feeding device for treating soil with a hardenable binder to form a binder-stabilized mass; and at least one third feeding device for feeding said binder-stabilized mass into a space delimited by the sleeve structure; wherein the apparatus is configured to treat the soil with a geopolymer or an alkali-activatable hardenable mixture, whereby a binder-stabilization layer according to claim 1 is arranged to be formed inside the sleeve structure.
25. The apparatus according to claim 24, wherein the apparatus further comprises a blade device for removing the soil from the foundation; said second feeding device is configured to treat the removed soil with the binder; and said first feeding device is configured to install the sleeve structure and the stabilizing-material treated removed soil back to the foundation.
26. A method for stabilization of a foundation, in which method the foundation is treated with at least one stabilizing material to improve its compression strength; and a stabilized structural layer of the foundation is arranged in a space delimited by a sleeve structure; wherein a geopolymer or an alkali-activatable mixture is used for stabilizing stone material.
27. The method according to claim 26, wherein stone material is taken from the foundation; the stone material is treated with a hardenable binder; the stabilization-treated stone material is fed into a space delimited by a sleeve structure; and the taken stone material is returned back to the foundation after the treatment.
28. The method according to claim 26, wherein the stabilization is performed without adding new stone material.
29. The method according to claim 26, wherein the stabilized structural layer is protected against moisture by means of the sleeve structure.
30. The method according to claim 26, wherein dissolution of materials of the stabilized structural layer and their flowing into the environment are prevented by means of the sleeve structure.
Description
SHORT DESCRIPTION OF THE FIGURES
[0143] Some embodiments of the proposed solution are illustrated in more detail in the following figures, in which
[0144] FIG. 1 is a schematical and simplified diagram presenting different layers of a road structure,
[0145] FIG. 2 is a schematical and simplified diagram presenting a composition of one binder-stabilized structural layer,
[0146] FIG. 3 is a schematical and simplified diagram presenting some additional features and components which may be included in a stabilized structural layer,
[0147] FIGS. 4 - 7 schematically illustrate some possible profiles and structures of sleeve structures,
[0148] FIGS. 8 and 9 illustrate sleeve structures arranged in a longitudinal direction next to each other over part of a wider road structure,
[0149] FIG. 10 schematically illustrates a cross-section of one road structure as seen from a longitudinal direction of the road,
[0150] FIGS. 11 - 14 schematically illustrate some seam structures of a sleeve structure,
[0151] FIG. 15 schematically illustrates one sleeve structure comprising a gas-permeable portion,
[0152] FIG. 16 schematically illustrates a detail of one sleeve structure comprising a corrugated base profile,
[0153] FIG. 17 schematically illustrates one apparatus for stabilizing a road structure or a foundation by means of a binder and a sleeve structure,
[0154] FIG. 18 schematically illustrates one sleeve structure which encloses a binder-stabilized mass and inside which there are stiffeners as seen in a longitudinal direction,
[0155] FIG. 19 schematically illustrates one road structure, the edges of which comprise binder-stabilized edge parts arranged inside a sleeve structure, as seen in a longitudinal direction, and
[0156] FIG. 20 schematically illustrates a road structure with a lightening structure passing over a depression in the roadbed as seen in a transverse direction.
[0157] For clarity reasons, some embodiments of the proposed solutions are illustrated in the figures in a simplified form. The same reference numbers are used in the figures to refer to the same elements and features.
DETAILED DESCRIPTION OF SOME EMBODIMENTS
[0158] As seen in FIG. 1, a road structure 1 typically comprises a subsoil 2 over which a pavement structure 3 of the road is provided. The pavement structure 3 comprises a plurality of successive layers which may include a surface layer 4, a base layer 5, a sub-base layer 6 and a drainage layer 7. There may be more or fewer of the structural layers depending on the circumstances. The structural layers may be as known per se in structure and properties. One or more of these structural layers may be treated with a hardenable binder and arranged inside a sleeve structure to stabilize the structural layer.
[0159] In FIG. 2 it is presented that a stabilized structural layer 8 comprises a hardenable binder 9 by which the stone material 10 of the structural layer 8 is reinforced. The stone material 10 may be for example sand, gravel, broken stone, crushed material or the like. The stabilized material or mass is further applied in a space delimited by a sleeve structure 11. The sleeve structure 11 may be as described in this document.
[0160] FIG. 3 lists additional features which may be included in a binder-stabilized structural layer. As mentioned above in this document, the mass applied inside a sleeve structure may comprise a fibre reinforcement 12 and the mass may be foamed 13. Further, for example a geopolymer or an alkali-activatable mixture 14 may be used for the stabilization of the stone material. Additionally, a filler 15 may be mixed in the mass and its strength may be improved by using separate stiffener elements 16. The mass may be electricity-conducting 17 and storing.
[0161] The sleeve structures 11 illustrated in FIGS. 4 and 5 each comprise two superposed films 18a, 18b extending in a longitudinal direction of the road, the longitudinal edges 19a, 19b of which films are closed and between which films the material treated with a hardenable binder is applied. Thereby, after fixing the edges the films 18a, 18b form a tube having a closed cross-sectional shape.
[0162] On the other hand, it is also possible that the edges 19a, 19b are not fixed to each other, but the films 18a, 18b are overlapped with each other, or alternatively the edges of the films are folded in such a way that a desired structure can be formed.
[0163] In FIGS. 4 and 5 the upper film 18a forms a cover K and the lower film 18b forms a base P. The upper film 18a is arranged to extend wider than the lower film 18b in a transverse direction of the road structure, whereby both longitudinal edges of the upper film 18a comprise wings 20. The cover K is thus wider than the base P, whereby the downwardly oblique wings 20 may guide water away from the road structure. The length of the wings 20 may be selected as desired.
[0164] FIGS. 6 and 7 illustrate tubular-shaped sleeve structures 11 that may comprise one or more seams or they may have a seamless structure. As shown, the cross-sectional shape of the sleeve structure 11 may be selected on a case-by-case basis. The cross-section may be angular, have curved shapes or their combination. Further, the width L of the sleeve structure may be selected according to the width of the driveway of the road and it may comprise one driveway or two driveways. The height H may be selected on a case-by-case basis.
[0165] In FIG. 8, two stabilized structural layers 8a, 8b inside a sleeve structure 11 are arranged next to each other in a longitudinal direction of the road, whereby a wider road may be covered. As shown, the shape of the structural layers may be asymmetrical, i.e. they may be thicker in the middle than at the edges, whereby a curved surface can be easily formed at the upper surface of the road, which curved surface has a gradient towards the edges. A joint strip 21 or a corresponding element may be arranged at a longitudinal seam between the structural layers 8a and 8b. It is clear that there may also be more than two structural layers arranged side by side. Thus, a bicycle driveway may be formed at the edge of a vehicle driveway by means of a third structural layer, or an overtaking lane, bus stop or other widening may be provided at a desired location of the road.
[0166] In FIG. 9, identical stabilized structural layers 8a, 8b are arranged next to each other. The seam may be filled by means of stone material to be applied above or for example with bitumen or some other elastic mass.
[0167] FIG. 10 illustrates one road structure 1 in which a binder-stabilized structural layer 8 is the base layer 5 over which a levelling layer 22 is further arranged. The levelling layer 22 may be a protective layer or a layer that enables shaping of the road surface and protects the sleeve structure 11. The levelling layer 22 may be crushed material. On top there is a surface layer 4 which may be crushed material, oil gravel, concrete or asphalt. Under the structural layer 8 enclosed within the sleeve structure 11 there may be the normal sub-base layer 6 and drainage layer 7 which are part of the pavement structure 3 and of course the subsoil 2 under the pavement structure 3.
[0168] FIG. 11 illustrates a seam S of a sleeve structure 11, which is a lap seam. The lap seam may comprise a welded joint 23 or alternatively the seam S may be fixed with glue or the like.
[0169] The seam S illustrated in FIG. 12 is a butt seam that may be strengthened by means of adhesive material or mass 24.
[0170] In FIG. 13, the seam S is also a butt seam, but this time the seam S is strengthened by means of a joint strip 25.
[0171] In FIG. 14, a gas-permeable strip 26 or portion is arranged in a seam area S. The strip 26 may be such that it prevents the access of liquid through the strip but allows a gas to pass through.
[0172] FIG. 15 illustrates a sleeve structure 11, the structure of which comprises a gas-permeable portion 27. The portion 27 may be in the upper portion of the sleeve 11, whereby the gases naturally pass out from the structure through the portion. The material in this portion 27 may be such that it prevents the access of liquid through the material but allows a gas to pass through. The shape of the sleeve structure 11 may of course be any type of shape when applying this feature.
[0173] As illustrated in FIG. 16, the base 18b, or some other portion, of the sleeve structure 11 may comprise a profiled portion 28 that may have a corrugated shape. The corrugation may be angular or of a curved shape. Bar-type stiffeners 29 or ropes 30 may be provided in connection with the corrugated profile on the inner surface of the sleeve structure 11. Further, the sleeve structure 11 may comprise electric conductors 31 and data communications cables 32. Additionally, the sleeve structure 11 may be equipped for example with power sensors 33 and cables 34 monitoring the temperature. Said equipment 29 - 34 may also be located in other places in addition to the base of the corrugated profile.
[0174] FIG. 17 illustrates an apparatus 35 for treating a structural layer of a road structure 1. The apparatus comprises a movable vehicle 36 having a blade device 37 for removing the soil from the surface of the road structure 1 while the apparatus 35 is being moved in a driving direction A. The blade device 37 may be for example a milling machine. The removed stone material, or for instance old asphalt, is conveyed by a conveyor 38 to a feeding device 39 in which a binder is mixed into the material from a container 40 for stabilizing it. The feeding device 39 comprises a mixer 41 in which a hardenable mass is formed. There may of course be several containers 40, if several components are used in the stabilization. The resulting mass is fed between two films. The film may be fed from feeding rollers 42a, 42b. The edges of the films may be connected by means of a seaming device 43. Alternatively, only one film is fed from one feeding roller 42a and its edges are turned up by means of guide members and finally in a tubular manner to the upper surface at which the seam may be fixed by means of the seaming device 43. The formed tubular sleeve structure 11 and the stabilized mass inside the structure are fed as a continuous structural layer 8 along an inclined feeding surface 44 to the back side of the apparatus 35. The apparatus 35 is thus able to produce the structural layer 8 in a continuous process at the same time as it moves in the direction A. The apparatus 35 lays the geotube from its rear end in a direction B. The feeding surface 44 may be a planar surface, or it may comprise rollers or other rolling elements. Further, in connection with the feeding surface there may be a vibrator V, whereby the binder-stabilized mass will be compacted as it passes from the apparatus 35 to the road foundation.
[0175] FIG. 18 illustrates one structural layer 8 in which a sleeve structure 11 encloses a binder-stabilized mass and inside which stiffeners 16 are provided. The stiffeners may be fixed to the base P of the sleeve structure 11, which base is subject to tensile stress during use due to bending. The stiffeners may have for example an I-profile and they may be metal, plastic material or composite material.
[0176] FIG. 19 illustrates one road structure 1 having a binder-stabilized structural layer 8 enclosed within a sleeve structure 11 in its pavement structure 3. Additionally, the edges of the road structure 1 also comprise binder-stabilized edge parts 8c, 8d arranged inside a sleeve structure 11. These edge parts 8c, 8d may form the embankment or shoulder of the road structure and may thereby speed up the construction of the road and facilitate road maintenance. Further, the edge parts 8c, 8d may be provided with a ready ditch profile 45, technical installations 46 or supports 47. The technical installations 46 may be for example conductors, measuring devices and fixing elements. The supports 47 may be for example elements intended for supporting and fixing railings, lampposts, traffic signs and the like. Further, the edge parts 8c, 8d may comprise integrated or separate extension parts 8e which also comprise a binder-stabilized structure enclosed within a sleeve structure. The counter embankment of the road structure may be supported and construction of the road speeded up by means of the extension part. Further, maintenance of the road may be facilitated and safety improved when vegetation at the edges of the road may be prevented.
[0177] FIG. 20 illustrates the use of a binder-stabilized structural layer 8 arranged inside a sleeve structure 11 in passing over a depression 49, dip, furrow or the like. The stabilized structural layer 8 is part of the base layer 5a, 5b of the pavement structure 3 and it may comprise longitudinal stiffeners 16. The mass inside the sleeve structure 11 may be foamed, whereby the thickness of the structural layer 8 may be high without the risk that its own mass increases too much. The structural layer 8 may thus be a lightening structure by means of which the construction of the road may be significantly speeded up and transport of filler soil saved.
[0178] The solution is presented in the figures in connection with a road structure, which is one significant application of the solution. In addition to that, the features and details described above may be used in the foundations of different fields and storage areas. In this case a plurality of foundation elements formed by a sleeve structure and a binder-stabilized mass may be arranged side by side. The seams may be protected with separate protective films or membranes. A surface layer may be applied to the surface, which surface layer protects the structure and gives the intended properties for the structure.
[0179] The proposed solution is also applicable to the stabilization of subsoils and foundations of halls and large buildings. Further, also the foundations of different pools and clamps may be stabilized as presented in this document.
[0180] The figures and their description are only intended to illustrate the idea of the invention. However, the scope of protection of the invention is defined in the claims of the application.
