Concrete

Concrete is the composite construction materials, which collects cement and other cementitious  materials such as fly ash and slag cement, aggregate, water, and chemical admixture.  A concrete is used to make pavements, pipe, architectural structures, foundation, bridges, roadways, overpasses, parking structures, brick/block walls, fences, etc. The concrete is used more than any other any made materials in the world. The mostly used types of concretes are reinforced concrete, prestressed concrete and precast concrete.

Reinforced Concrete

The reinforced concrete is the one which incorporates the, reinforcement bars, reinforcement grids, plates to strengthen the concrete in tension. The concrete that is reinforced with iron or steel is referring to Ferro concrete. Concrete is strong in compression but weak in tension, but adding the reinforcement will increases the strength in tension. The reinforcement should have the following properties for strong, ductile, and durable construction.

• High strength
• High tensile strength
• Good bond to the concrete
• Thermal compatibility

Prestressed Concrete

This is the method for overcoming concrete natural weakness in tension. It is used to produce beams, floors, or bridges with a longer span. Prestessing tendons (generally of high tensile steel cables or rods) are made use to give the  clamping load which produces compressive stress which balances the tensile stress, that the compression member of the concrete would otherwise experience due to bending load. Prestressing can be proficient in these ways: pre tensioned concrete, and bonded or unbounded post tensioned concrete.

Precast Concrete

Precast concrete is a construction product, which is produced by casting concrete in the reusable mold or form. In the controlled environment, it is cured and transported to the construction site. The utility of a precast concrete system offers many potential advantages over site casting of concrete. As the production of precast concrete is performed in the ground level, that helps with safety throughout the project.

The states across the United States wanted a precast plant to be certified by the Architectural precast Association (APA), National Concrete Association (NPCA) or precast prestressed concrete institute (PCI) for a precast producer to supply their product to a construction site sponsored by state and Federal DOTs. There are various types of precat concrete forming system for architectural applications, varying in size, function and cost. This architectural panels are also used to cover all or the part of a building façade free standing walls used for landscaping.

Questions:

• What is concrete?
• Explain precast concrete?