Design of Prestressed Concrete Storage tank

Prestressed concrete, or rather more properly, 'pre-compressed' Concrete, is a latest development of reinforced concrete. Under full working load in reinforced concrete structures, the concrete is fractured and its tensile zone does not contribute to the strength of the structure, its resistance to tension being only about 1/10th to 1/15th of that in compression. Further the elongation of the reinforcement, both for mild steel and for high tensile steel, when stressed to 18,000 lbs/sqin is 0.06% (e=t : Es=18×10³ : 30×10⁶=0.06%). The surrounding concrete cannot bear the strain, and long before this working load is reached, the concrete is fractured.