Precast concrete is the construction product that is formed by casting the concrete in the moulds of the desired size which is then cured and transported to the site for assembling.
Fencing posts, pipes, paving slabs, artificial concrete blocks, etc are the products of the precast concrete.
The precast products are prepared as follows:
a. Preparation of moulds of steel, sand or timber is done according to the shape of the product required.
b. As per the design, the reinforcement, if any, is placed in the moulds.
c. The concrete is mixed in the desired proportion and then placed in the mould; the
finishing of the products is then carried out.
d. The products are then adequately cured in specially constructed tanks.
e. Dispatching of products is then done for use.
Uses of Precast Concrete
a. Used in the structural components such as beams, columns, floors, etc.
b. Used in various utilities such as tunnels, septic tanks, water tanks, etc.
c. Used in the preparation of concrete pipes, concrete blocks, etc.
Advantages of Precast Concrete:
1. There is no necessity of provision of joints in the precast construction.
2. Required labour manpower can be trained easily.
3. Desired finish and shape can be given with high accuracy.
4. Quality of produced concrete is superior (due to better control on the concrete production in factory).
5. The precast concrete structures can be dismantled and reused according to needs.
6. The moulds used are more durable and accurate and can be used multiple times.
7. Reduced amount of scaffolding and framework.
8. Less time is required for the completion of the work.
Disadvantages of Precast Concrete:
1. Improper handling may lead to the damage of precast units during the transporting process.
2. For the purpose of lifting and moving of the precast units; special types of equipment are required.
3. It is quite difficult to produce satisfactory connections between the members of precast.