Concrete is a building material that consists of aggregate and a binding substance. The compressive and tensile strengths are produced by the aggregate in conjunction with the binding material (cement). The compressive strength of concrete protects it from deformation produced by the structure's compression, whereas the tensile strength protects it from distortion caused by breaking or expansion. The aggregate and binding material used in concrete determine the concrete's compressive strength entirely, but the tensile strength is determined in part by the aggregate and binder, and in part by the reinforced material (steel, fibre, and other metallic cables).
Concrete is classified into numerous categories based on its composition, as shown below:
Plain/ Ordinary Concrete:
This is the most frequent and common sort of concrete. It's made with a 1:2:4 mix of cement, sand, aggregate, and water. In these types of concrete, ordinary cements such as OPC and PPC are commonly employed. This concrete works well for laying floors, paving roofs, and other flat surfaces. It has the same compressive strength as other varieties of concrete, but it has a lesser tensile strength than those that include reinforcing materials such as steel, iron, metal, and cable.
Self Compacting Concrete:
A concrete mix with low yield stress, high deformability, good segregation resistance, and moderate viscosity is known as self-consolidating concrete or self-compacting concrete.
Precast Concrete:
Precast Concrete refers to the construction of a concrete structure that has been completely prepared offsite. Off-site, the appropriate structure is produced, cast, and cured in reusable moulds, usually in a controlled manufacturing environment. To build a full structure, precast concrete elements can be linked to other elements. They're commonly utilized for structural elements like wall panels, beams, columns, floors, stairwells, pipes, and tunnels.
Reinforced Concrete:
Any type of concrete that uses reinforcing materials such as steel bars, cable, mesh, and fibres to provide high tensile strength is known as reinforced concrete. Heavy loads and burdens are supported by this type of concrete.
Prestressed Concrete:
Prestressed concrete is a structural material that allows for the placement of specified engineering stresses in members to counterbalance the stresses that will arise when they are loaded. It combines the great compressive strength of concrete with the high tensile strength of steel in a single material. Stresses are borne by steel reinforcement in reinforced concrete, whereas induced stresses throughout the structural element sustain the load in prestressed concrete.
Floor beams, piles, and railway sleepers, as well as constructions like bridges, water tanks, roofs, and runways, are increasingly often made with it.
High Density Concrete:
Crushed rocks are utilized as the coarse aggregate in this type of concrete, which has a high density. This type of concrete has a higher density and weight than other concretes. The concrete's compressive strength comes from the indestructible crushed stone aggregate, while the tensile strength comes from steel bars. This type of concrete is utilized in the construction of structures that are designed to withstand enormous loads and burdens. Their own dead weight is likewise quite substantial. The beams, as well as the bridge decks and abutments, are made of high-density concrete.
Polymer Concrete:
In place of cement, polymeric materials such as Furan Resins, Acrylics and Styrene-Acrylics, Vinyl Acetate-Ethylene (VAE), Urea Formaldehyde Resin, Polyvinyl Acetate (PVA), Epoxy Resins, Methyl Methacrylate MMA, Styrene and Polyester Styrene, Methanol Resin, Styrene-Butadiene Resin (SBR), Polyurethan, are applied as binding material.
Cellular Concrete:
Cellular concrete is a light-weight concrete. The concrete has a lower viscosity. Its flow-ability enables it to reach the form's corners and level itself. It's commonly used to build floor slabs, window panels, and roofing. Lighter rock aggregates such as pumice, scoria, shale, and clay are used in this form of concrete.
Glass Reinforced Concrete:
Glass Reinforced Concrete is made up of high-strength, alkali-resistant glass fibres that are inserted in a concrete matrix. The structure's tensile strength is provided by the fibres, while the compressive strength is provided by the concrete matrix.
Smart Concrete
In order to adjust an electrical resistance in reaction to stresses or stress, a small amount of carbon fibre is added to the usual concrete mixture. This aids in the detection of potential concrete problems prior to failure.Air-Entrained Concrete:
This is a type of plain concrete that contains small air bubbles ranging in size from a few thousandths of an inch to a few hundredths of an inch in diameter, and which typically make up 4 to 7% of the total volume of the concrete.
When water freezes, the air bubbles create chambers for it to expand into, reducing internal pressure on the concrete. It's made by mixing in air-entraining chemicals during the mixing process, or by employing air-entraining Portland cement.
~~~~~~~~~~~~~~
Author: Rajib Dey
Social Links :
