Reinforced concrete is a combination of steel bars and cement joined together. By combining the two different materials, the best building material is created. There are many advantages of reinforced concrete, such as increased compressive strength, more durable than any other building procedure, and it is a fire and water resistant material. Reinforced concrete can also withstand other forceful weather events.
Reinforced concrete can be made even better with post-tensioning. This term basically means pre-stressing. Special equipment is used to stress the concrete before it is brought into use in a load bearing capacity. Steel cables are placed in a plastic sleeve. They are then positioned in the concrete forms. When the concrete is poured and has set some but not all the way, the cables are pulled, or tensioned, and then anchored on the outer edges of the concrete.
What are the advantages and applications of using this post-tension method?
Floor joists and beams can span longer lengths that usual when reinforced concrete is post-tensioned. Engineers use post-tensioned beams and joist to provide greater variety with their building methods and practices.
Concrete cracks due to shrinkage or uneven drying are reduced. This means there are less joints to fill, but it also means a structure can be built more efficiently. Tennis courts are a good candidate for post-tension concrete construction. The courts will be far less likely to crack. Concrete driveways are another good application for post-tensioned concrete.
Concrete slabs can be made thinner. Because the rebar has been post-tensioned, the concrete is stronger even though it is thinner. Post-tensioning greatly reduces the brittleness inherent to concrete, especially when used in thinner applications. Thinner concrete provides more design freedom and aesthetic options. For example, concrete countertops can be fashioned out of thinner sheets of concrete without concern they will become brittle and break. Concrete can be dyed or stamped and patterned to look like more expensive natural materials. Slabs that have post-tensioned steel cables can be built on softer ground. The ability to use a thinner slab reduces the load bearing weight on the soil. This allows a slab to "float" over the area better rather than sinking into it. Expansive soil, or soil that is likely to move and shift, can be risky to build on. But with post-tensioned concrete, builders can construct homes on slabs-on-ground without a problem. Other unique applications include cement walls, cement water tanks, and cement retaining walls.
