The present disclosure provides a combined prefabricated reinforced concrete stair mold and a splicing method. The combined prefabricated reinforced concrete stair mold comprises a bottom mold platform (1), wherein an upper platform module (2), a tread module (3) and a lower platform module (4) which are spliced with one another are sequentially arranged on the upper surface of the bottom mold platform (1), and corner modules (5) are arranged between the upper platform module (2) and the tread module (3) and between the tread module (3) and the lower platform module (4); the tread module (3) comprises a tread upper surface mold (6) and a tread lower surface mold (7); and the tread lower surface mold (7) comprises a plurality of combined templates (8) formed by mutual splicing, and the tread upper surface mold (6) comprises a plurality of tread splicing pieces (9) formed by mutual splicing.

A two-way retractable building formwork apparatus includes a substrate module having a mounting surface, a first side bar mounted on one end of the mounting surface that extends along a first direction, a second side bar mounted on another end of the mounting surface that extends along a second direction transverse to the first direction and fixed to one end of the first side bar, a first retractable unit mounted on the mounting surface opposite to the first side bar and extendable along the first direction to fixedly connect to the second side bar, and a second retractable unit mounted on the mounting surface opposite to the second side bar, extendable along the second direction to fixedly connect to the first side bar, and further connected to the first retractable unit.

A connection system includes a turnbuckle having a first set of threads and a second set of threads disposed on an inner surface of the turnbuckle. The turnbuckle is configured to couple two threaded components to one another via rotation of the turnbuckle in a first direction. In addition, the connection system includes a compression washer configured to compress as the turnbuckle rotates in the first direction. The compression washer is configured to apply a longitudinal force to the turnbuckle while the compression washer is compressed to increase resistance to rotation of the turnbuckle in a second direction, opposite the first direction.

A turnbuckle-style support strut with tunable stiffness, wherein the turnbuckle-style support strut uses opposing stacks comprised of one or more Belleville spring washers to provide the tunable stiffness to support a given application.

Various implementations described herein are directed to a formwork system. In one implementation, the formwork system includes aluminum extrusions and aluminum castings. The aluminum castings and the aluminum extrusions can be assembled by being pressed and riveted together.

A multipurpose reusable support device is provided. The device includes a horizontal support member and a vertical support member connected at an intersecting pivot point to establish a support angle. The horizontal support member and the vertical support member are connected via an adjustable support member such that the device forms a shape substantially similar to a triangle. The adjustable support member may further include an adjustable ratchet configured to adjust the length of the adjustable support member which in turn adjusts the support angle to fit the needs of a user.

The present invention corresponds to a formwork mechanism for casting and molding concrete, comprising a coffer having a sheet and four plates around the sheet perimeter. Each plate has holes arranged on its front face. Also, the formwork mechanism includes a structural element, connected to one of the plates by fixing means. On the other hand, the structural element has lateral perforations that are aligned with the holes of one of the coffer plates. Fixing means pass through the holes and side holes. The structural element may be a beam, a three or four-beam T, and combinations thereof. On the other hand, using several coffers interconnected with structural elements, formworks are constructed for casting flat reticular slabs; and also for curved reticular slabs with greater slab thickness near the beams supporting the slabs in comparison to the span of the slabs.

Concrete form assemblies having insulating foam panels are created using locking members embedded within the insulating foam panels and ties each having a pair of side rails for coupling two insulating foam panels together at a predetermined distance apart, the locking members and side rails being adapted so that either side rail can be coupled to either locking member and either of the ends of the rails and locking members can be toward the top or bottom of the assembly when the rails are coupled to the locking members.

The invention relates to a corner shuttering element with two limbs (12, 14) arranged at an angle to each other, on the outer edge of which limbs (12, 14), edge strips (16, 18) are arranged that can be retracted and extended by means of articulated levers (24, 26), wherein the edge strips (16, 18) can each be aligned and fixed in their position by means of a plurality of locking elements (34) arranged distributed over the height of the corner shuttering element, and wherein the locking elements (34) are arranged on guides (32) for pull-out webs (30) of the edge strips (16, 18).

A connection assembly for formwork elements includes a counterplate, a bolt, and a bolt block. The counterplate can include a plurality of surfaces having differing heights that selectively engage with a waler during engagement or disengagement of the bolt from the formwork element. The formwork element can include a J-shaped waler that allows for easy climbing and/or hanging of objects on a site. The connection assembly can include a bolt block that removably engages a formwork element.