Monday, November 17, 2014

Increasing the Tensile Strength of Concrete


The aggregate in a concrete mix effectively carries the compression load to make concrete strong in compression.  However concrete is weak in tension as the cement holding the aggregate in place is susceptible to cracking and can result in the structure failing.  To carry the tensile load, concrete is reinforced with steel reinforcing bars (rebar), steel fibers, glass fibers, or plastic fibers.

Both brittle and rigid, concrete may crack or break under high pressure conditions and shear stresses caused by wind, earthquakes, and other forces.  By embedding rebar or other reinforcement into the concrete, it provides a higher tensile strength and ductility to the concrete and gives buildings the required strength to stand up to seismic activity. 

Generally concrete only needs a relatively low percentage of rebar to achieve the maximum performance required for a specific construction project.  In a typical concrete beam, about 1% of rebar is added to the concrete, while in a column, it can be up to 6% rebar.  This formula achieves an economical solution for providing strength, ductility, and durability to the construction project since the cost of steel far exceeds the cost of concrete.

Types of reinforced concrete include precast or cast-in-place and are used in the construction of slabs, walls, foundations, beams, and columns.  Many structures built today would not have been possible without reinforced concrete.   Another type of reinforcement is referred to as post-tensioning.   Wikipedia states, “Bonded post-tensioned concrete is the descriptive term for a method of applying compression after pouring concrete and the curing process (in situ). The concrete is cast around a plastic, steel or aluminum curved duct, to follow the area where otherwise tension would occur in the concrete element.” 

Precision-engineered rebar and post-tension cable is fabricated in state-of-the-art facilities such as the plants owned by The Conco Companies.  We utilize the latest technologies to ensure accuracy and increase productivity.  Our plants are outfitted with modern shear lines, benders and post-tension cable manufacturing equipment to meet the most exacting specifications. 

Source: en.wikipedia.org/wiki/Concrete

When your project demands exceptional services and the best value, Conco can deliver.  We have been offering premium concrete services throughout the Western U.S. since 1959, and have four regional offices serving California, Washington, Oregon, Nevada and Colorado. With state-of-the-art equipment and modern facilities, we work diligently to meet goals and stay within budget.



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