Q1: If S_b, is the average bond stress on a bar of diameter d subjected to maximum stress t, the length of the embedment l is given by

ANS:D -

The length of embedment (l) required for a bar subjected to maximum stress (t) and average bond stress (b​) on a bar of diameter (d) can be determined using the relationship derived from bond stress equations. The embedment length is crucial for ensuring proper bond between the reinforcing bar and the surrounding concrete. One commonly used relationship to calculate the embedment length is provided by the following equation: l=Sb​×π×d2​/4*T Where:

• l = Length of embedment
• Sb​ = Average bond stress
• d = Diameter of the reinforcing bar
• t = Maximum stress on the bar

This equation is derived from the equilibrium of forces acting on the bond between the reinforcing bar and the concrete. It ensures that the bond stress exerted on the bar due to the surrounding concrete is sufficient to resist the maximum stress applied to the bar. By using this equation, the proper length of embedment can be calculated to ensure adequate bond strength between the reinforcing bar and the concrete, thereby preventing premature bond failure and ensuring the structural integrity of the reinforced concrete element.