How is precast concrete made?
Precast concrete structures are manufactured at the factory and then shipped to the site for installation. However, have you ever thought about how to make precast concrete products?
Precast concrete structures are used in many types of buildings and for many different purposes, including electrical and communication facilities, rainwater storage and transportation, wastewater applications, bridges, building structures, and more.
There are good reasons to use precast concrete - it offers many benefits for the project, including quick and easy installation, because there is no on-site form to build or wait for concrete to solidify on site, and to improve site safety by reducing site safety, And to provide high quality, high strength products, because it is produced in a controlled environment.
The process begins with engineering. In each project, a design engineer or owner (such as the Department of Transportation, DOT) sets requirements for its prefabricated components. When we get the drawings and requirements, each product is designed in-house according to the specifications of the design engineer and the owner.
Engineers ensure that each prefabricated structure has the appropriate reinforcement (rebar) and meets the structural requirements of its installation area. Some important considerations include the type of soil, whether the prefabricated structure is adjacent to a building or other structure, and the water table in that area.
After the calculation is complete, the drafting team will create detailed drawings. These drawings, called submissions, are then sent to the design engineer or owner for approval. Once the drawings are approved, the engineering and drafting team will produce the production drawings and send them to the factory for manufacturing. The production sheet set includes a bill of materials or bill of materials that includes all components entering the product, including the size and length of each bar and how much concrete (in cubic yards) will be used.
Prepare steel cage
When the production team receives the drawings, the first step is to assemble the reinforcement cage. To do this, they must cut all the steel bars to the appropriate length according to the BOM, then bend and tie them together. Reinforced wheelchairs, sometimes called horse wheels, are round plastic parts that can be hooked onto steel bars to ensure they are properly positioned in the wall of the prefabricated product - not too close to either side of the wall - in line with the engineer's design and meet structural requirements.
While building the steel cage, another team is preparing these forms. The team inspected the drawing to see if the structure had any openings or knocks, and placed the foam insert (which was removed after the concrete was cured) into the template.
Use openings where pipe connections or where other connections are required. The tapper is a thinner wall portion that allows the opening to be "knocked out" at the site once the subcontractor knows where the electrical conduit or communication line enters the vault. These inserts are embedded and fixed to the formwork with the appropriate lifting hardware so they do not move when the concrete is poured.
Next, the team used a molding oil to ensure that the concrete was easily released from the form after curing. Finally, use a crane to lift the cage and drop it into the formwork. Prior to casting concrete, each product is pre-cast by a certified quality control technician to ensure it meets production drawings. Once approved, the technician will sign and mark the form indicating approval of the poured concrete.