Concrete

As apart of a Structures, Materials and Spaces module. This blog will talk about the material concrete, it's uses and it's enrollment through generations.

Concrete is a material made up of limestone. In construction it is commonly used as a base or as the foundations of a building. 

Concrete is characterised by the type of aggregate or cement used, by the specific qualities. In ordinary structural concrete, the character of the concrete is largely determined by a water-to-cement ratio. The lower the water content, all else being equal, the stronger the concrete. The mixture must have just enough water to ensure that each aggregate particle is completely surrounded by the cement paste, that the spaces between the aggregate are filled, and that the concrete is liquid enough to be poured and spread effectively. Another durability factor is the amount of cement in relation to the aggregate. Where especially strong concrete is needed, there will be relatively less aggregate.

The strength of concrete is measured in pounds kilograms per square centimetre of force needed to crush a sample of a given age or hardness. Concrete’s strength is affected by environmental factors, especially temperature and moisture. If it is allowed to dry prematurely, it can experience unequal tensile stresses that in an imperfectly hardened state cannot be resisted. In the process known as curing, the concrete is kept damp for some time after pouring to slow the shrinkage that occurs as it hardens. Low temperatures also adversely affect its strength. To compensate for this, an additive such as calcium chloride is mixed in with the cement. This accelerates the setting process, which in turn generates heat sufficient to counteract moderately low temperatures. Large concrete forms that cannot be adequately covered are not poured in freezing temperatures.

Concrete is used in the frame work of buildings also A concrete frame is a common form of structure, comprising a network of columns and connecting beams that forms the structural ‘skeleton’ of a building. This grid of beams and columns is typically constructed on a concrete foundation and is used to support the building’s floors, roof, walls, claddingetc.

Concrete frames can be precast which means they are manufactured off site, or can be cast on site.

Precast concrete frames are typically used for single-storey and low-rise structures. The concrete members are transported to site where a crane then lifts and places them into position to construct the frame.