Introduction On Prestressed Concrete Pole And Its Advantages
Prestressed of concrete is defined as the application of compressive stresses to concrete member. The zones of the member ultimately required to carry tensile stresses under working load condition are given so that the tensile stresses developed by these working loads are balanced by induced compressive strength. Prestress can be applied in two ways pre-tensioning and post tensioning.
Pre tensioning is the application before casting of the tensile force to high tensile steel tendons around which the concrete is to be cast. When the placed concrete has developed sufficient compressive strength a compressive force is imparted to it by releasing the tendons, so that the concrete member is in a permanent state of prestress.
The use of pre stress concrete offer distinct advantages over ordinary reinforced concrete. These advantages can be briefly listed as followed
Prestressed minimizes the effort of cracks in concrete element by holding the concrete in compression.
Prestressed allows reduce beam depths to be achieved for equivalent design strengths.
Prestressed concrete is resilient and will recover from the effects of a greater degree of over load than any other structure material.
If the member is subject to overload, cracks, which may develop will close up on removal of the overload.
Prestressed enable both entire structure element and structures to be formed from a number of precast units. e.g. segmented and modular construction.
Lighter element permit the use of longer spanning member with higher strength to weight characteristic.
The ability of control deflection in pre-stressed beams and slabs permits longer spans to be achieved.