Precast concrete consists of concrete (a mixture of cement, water, aggregates and admixtures) that is cast into a specific shape at a location other than its inservice position. The concrete is placed into a form, typically wood or steel, and cured before being stripped from the form, usually the following day. These components are then transported to the construction site for erection into place. Precast concrete can be plant-cast or site-cast, but this book deals specifically with plant-cast concrete.

Precast concrete components are reinforced with either conventional reinforcing bars, strands with high tensile strength, or a combination of both. The strands are retensioned in the form before the concrete is poured. Once the concrete has cured to a specific strength, the strands are cut (detensioned). As the strands, having bonded to the concrete, attempt to regain their original untensioned length, they bond to the concrete and apply a compressive force. This “precompression” increases load-carrying capacity to the components and helps control cracking to specified limits allowed by building codes.

Developers are now adopting precast concrete and engineering homes technology in their projects after encouraging results of these technologies in Europe and the Middle East.

Interior Craft, Alstone, Orris Infrastructure , Amrapali, Supertech, etc, have adopted a new building system that offers speed, quality and value at the same time. The use of such technology helps in saving up to 64% of the total man hours needed using conventional methods. That is, if a building takes one year to raise using brick and mortar method, it can be completed in four months with precast and engineering homes method.

“Design Advantages” and benefits include:

  • Speed of construction, owing to the ability to begin casting components for the superstructure while foundation work is in progress. Precast concrete components can also be cast and erected year-round, without delays caused by harsh weather;
  • Aesthetic flexibility, due to the variety of textures, colors, finishes and inset options that can be provided. Precast is extremely plastic and can mimic granite, limestone, brick, and other masonry products. This allows it to blend economically with nearby buildings finished with more expensive materials;
  • Design flexibility, resulting from the long-span capabilities to provide open interiors;
  • Durability, which allows the material to show minimal wear over time and resist impacts of all types without indicating stress;
  • Energy efficiency, due to the material’s high thermal mass. This is enhanced by the use of insulated panels, which include an insulated core;
  • Environmental friendliness, as seen in its contributions to achieving certification in the Leadership in Energy & Environmental Design (LEED) program from the U.S. Green Building Council (USGBC); and
  • High quality, resulting from the quality control achieved by casting the products in the plant. Plants certified by PCI undergo stringent audits of their quality procedures, ensuring the quality of fabrication in these facilities.