What is Pre-cast Concrete?
The main difference between pre-cast concrete and cast-in-situ concrete is that the former is a factory-made product while the latter is made in the workplace. It is possible to manufacture well-made pre-cast products while maintaining a high level of finishes. Pre-cast products vary from simple structures such as fencing posts, pipes, paving slabs to elaborate and complex artificial concrete blocks.
The procedure for preparing pre-cast products:
(I) Wood, steel, or sand molds are made to shape the product.
(2) Reinforcement, if any, is put up in the molds as per design.
(3) The concrete is mixed in the desired quantities and placed in the mold.
( 4) Then the products are finished. Common products, such as fence-posts, sleepers, etc., are left in place, while products such as spinning tubes are finished.
(5) The products are then cured enough in specially built tanks.
(6) The products are then sent to use in the workplace. They can be mounted and positioned by light overhead cranes and small mobile cranes.
Advantages of pre-cast concrete:
( 1) High-quality concrete is produced.
(2) It is not necessary to provide hinges on pre-cast construction.
(3)Necessary labor can be easily trained in the production process of pre-cast components.
( 4) The molds used to make the pre-cast components are of steel with precise dimensions in all directions. These molds are more durable and can be used several times.
( 5)Pre-cast articles can give the desired shape and finish with precision.
(6) The pre-cast structures can be dismantled, when required and they can then be suitably used elsewhere.
(7) The transport and storage of various components of concrete for cast-in-situ work are eliminated when pre-cast members are adopted.
(8) The work can be completed in a short time when pre-cast units are adopted.
(9) For pre-cast structures the less amount of scaffolding is required.
Disadvantages of pre-cast concrete:
( 1) If not properly handled, the pre-cast units may be damaged during transport.
(2) Making satisfactory connections between pre-cast members becomes difficult.
(3) It is necessary to arrange special equipment for lifting and moving pre-cast components.
( 4) The economy achieved in pre-cast construction is partially offset by the amount to be spent on the transportation and maintenance of pre-cast members. It is, therefore, necessary to find the pre-cast factory in such a place, with transport and handling charges are being brought down to a minimum possible extent.
I hope you understand what is pre-cast concrete. For improving the knowledge in the civil word you may also read our articles like Manufacturing of cement etc.