The 2×4 Coupling Plate allows two boards to be reversibly coupled so that the lengths of the two boards may be added together. The coupling plates allows both boards to be separated without damaging them. This device allows a concrete fabricator to assembly two 2×4 boards together and hold them together to form a structure to contain liquid concrete. Once the concrete is set, the installer removes the two boards from the coupling plate so that the boards can be used on another concrete form.

A formwork system for supporting forming panels to form a horizontal concrete surface. The system includes a height-adjustable support having a central upstanding member providing a vertical abutment surface and a support arm having an inclined portion extending up and away from said central upstanding member. The system also includes a beam having a transverse bar proximate an end. The transverse bar is supported by the inclined portion of the support arm so that said transverse bar moves laterally relative to the inclined portion as the support arm is moved vertically. The beam also has a foot extending from the end of the beam and abutting the abutment surface. The abutment surface opposes lateral movement of the beam relative to the upstanding member.

A formwork system includes a height-adjustable support for supporting a beam in substantially horizontal or slightly inclined position that includes a support with a central upstanding member and a support arm. The support arm has a rounded socket, and the beam has a cylindrical mounting pin proximate its end. The socket and mounting pin are shaped and sized so that the mounting pin is retained within the socket and they together form a hinge joint. As the mounting pin is retained by the socket of the support arm, it does not shift laterally relative to the support arm as the support arm is vertically adjusted. The variance in the gap between laterally secured forming panels as a response to vertical shift of the support is dependent on the incline angle of the beam and the dimensions of the beam and the support arm. This is predictable within a defined tolerance.

A formwork system for supporting forming panels to form a horizontal concrete surface. The system includes a height-adjustable support having a central upstanding member providing a vertical abutment surface and a support arm having an inclined portion extending up and away from said central upstanding member. The system also includes a beam having a transverse bar proximate an end. The transverse bar is supported by the inclined portion of the support arm so that said transverse bar moves laterally relative to the inclined portion as the support arm is moved vertically. The beam also has a foot extending from the end of the beam and abutting the abutment surface. The abutment surface opposes lateral movement of the beam relative to the upstanding member.

A stay-in-place form comprises a plurality of elongated panels connectable to one another in edge-to-edge relationship. The plurality of panels comprises first and second panels connectable to one another in edge-adjacent relationship by a connection which comprises a contact joint. The first panel comprise a longitudinally extending first seal-retaining projection shaped to project outwardly from the outer surface of the first panel at a location spaced apart from a first outer-surface transverse edge of the first panel in a first transverse direction. The second panel comprising a longitudinally extending second seal-retaining projection shaped to project outwardly from the outer surface of the second panel at a location spaced apart from a second outer-surface transverse edge of the second panel in a second transverse direction opposite the first transverse direction. The first and second seal-retaining projections and the outer surfaces of the first and second panels defining at least a portion of a seal-receiving concavity which opens outwardly from the form when the connection is made.

A formwork system includes a height-adjustable support for supporting a beam in substantially horizontal or slightly inclined position that includes a support with a central upstanding member and a support arm. The support arm has a rounded socket, and the beam has a cylindrical mounting pin proximate its end. The socket and mounting pin are shaped and sized so that the mounting pin is retained within the socket and they together form a hinge joint. As the mounting pin is retained by the socket of the support arm, it does not shift laterally relative to the support arm as the support arm is vertically adjusted. The variance in the gap between laterally secured forming panels as a response to vertical shift of the support is dependent on the incline angle of the beam and the dimensions of the beam and the support arm. This is predictable within a defined tolerance.

A sealing structure for the bottom of a beam space between precast panels, comprising: a first precast panel and a second precast panel substantially aligned to each other along a single plane and spaced from each other by a space, each of the first precast panel and the second precast panel defining an inner edge adjacent to the space; a soft pad abutting the space for sealing a bottom of the space; a plate abutting the soft pad; a fastening device securing a first side of the plate and a second side of the plate to the first precast panel and second precast panel, respectively, so as to assist the soft pad in the sealing of the bottom of the beam space; wherein the fastening device does not contact the soft pad.

A stay-in-place form comprises a plurality of elongated panels connectable to one another in edge-to-edge relationship. The plurality of panels comprises first and second panels connectable to one another in edge-adjacent relationship by a connection which comprises a contact joint. The first panel comprise a longitudinally extending first seal-retaining projection shaped to project outwardly from the outer surface of the first panel at a location spaced apart from a first outer-surface transverse edge of the first panel in a first transverse direction. The second panel comprising a longitudinally extending second seal-retaining projection shaped to project outwardly from the outer surface of the second panel at a location spaced apart from a second outer-surface transverse edge of the second panel in a second transverse direction opposite the first transverse direction. The first and second seal-retaining projections and the outer surfaces of the first and second panels defining at least a portion of a seal-receiving concavity which opens outwardly from the form when the connection is made.

A grid beam slab formwork comprising of primary beams, secondary beams, multi-level drophead unit, and props. The multi-level drophead unit offers up to or more than six connection points for the primary beams and the secondary beams. The multi-level drophead unit allows the construction of an additional structure that otherwise requires a separate drophead or an adaptor thereby reducing an overall cost associated with the formwork. Moreover, the multi-level drophead unit enables the creation of the platform wherever needed. On the other hand, the adapter prevents entrapment of the sheathing members, such that the beams can be removed when the concrete has achieved required strength and the load can be taken by the props.

A stay-in-place form comprises a plurality of elongated panels connectable to one another in edge-to-edge relationship. The plurality of panels comprises first and second panels connectable to one another in edge-adjacent relationship by a connection which comprises a contact joint. The first panel comprise a longitudinally extending first seal-retaining projection shaped to project outwardly from the outer surface of the first panel at a location spaced apart from a first outer-surface transverse edge of the first panel in a first transverse direction. The second panel comprising a longitudinally extending second seal-retaining projection shaped to project outwardly from the outer surface of the second panel at a location spaced apart from a second outer-surface transverse edge of the second panel in a second transverse direction opposite the first transverse direction. The first and second seal-retaining projections and the outer surfaces of the first and second panels defining at least a portion of a seal-receiving concavity which opens outwardly from the form when the connection is made.