Question

The ultimate strength of the steel used for prestressing is nearly

• A. $250N/m{m}^2$
• B. $415N/m{m}^2$
• C. $500N/m{m}^2$
• D. $1500N/m{m}^2$

Answer 1

The correct option is D $1500N/m{m}^2$

Loss in prestress is in range of $100N/m{m}^2$ to $250N/m{m}^2.$ Thus high tensile steel having strength in range of $1200-1500N/m{m}^2$ is to be used so that even after there is loss there is sufficient prestress left in the concrete.