Till a few years ago, precast technology was not there, buildings structure was constructing brick-by-brick with the same old traditional method. But, this process is disappearing now with the origin of pre-cast technology.
Pre-cast concrete means a concrete portion of a structure that is cast and cured at a location that is not the site of construction. Once a precast concrete product is produced and all the undertaken quality controls are satisfactory, the unit is stored until delivery. It is then transported for use at another site.
Pre-cast structures are made in stages that start from engineering and go on to manufacturing of the reinforcement cage, form preparation and pre-pour inspection, concrete placement, curing and stripping, and culminating in post-pour work.
Once the mould is ready, the overhead crane is used to lift the cage and place it right in the middle of the form. When one set in done, a certified quality control engineer will conduct a pre-pour inspection to see that the product is in tandem with the original shop drawing. When this process completes an inspection has made to satisfy with all quality standard. A technician gives a go ahead to place the same structure to the site.
There are some laboratories where the material is given to test to satisfy that all the material which is in use, perfect. The raw material is always used or mixed as per the design requirements. Here they follow multiple tests to check the mix has the proper flow and there is no segregation of the aggregates.
This approved batch is transported to the product form on the production floor. The concrete is placed into the form and care is taken to allow the concrete to flow without trapping the conduits. Once the form is filled, the top is smoothed off.
Once the concrete has settled and has been removed from the form, it is then cured. The product may be covered in tarpaulin overnight to seal in the heat from the hydration process (where the product is constantly doused in water).
The stripping process involves opening the outer jacket of the form, attaching the lifting devices to the product and lifting it off the form.
Once the product has been removed, it is cleaned and a post pour inspection is conducted. If all design dimensions have been maintained and no visual defects are noted, the quality technician signs it off. The finished product is then transported to the storage area, while care is taken that it receives proper support as it awaits its requirement. When a requirement arises, the product is loaded onto a truck and properly secured to be transported to the site of construction.
Structures created with precast technology have been known to have superior quality and durability. Pre-cast technology has a huge list of benefits for those using this structures or technology.