Q1: A pre-stressed concrete member

ANS:D - possesses internal stresses.

A pre-stressed concrete member possesses internal stresses, making it distinct from traditional reinforced concrete members. Pre-stressed concrete is a construction material in which internal stresses are deliberately induced in a structure before it is subjected to external loading. These internal stresses are introduced to counteract the tensile stresses that will develop when the member is subjected to external loads, such as bending or axial loads. Pre-stressing is typically achieved by tensioning high-strength steel tendons or cables within the concrete member before it sets and hardens. Once the concrete has hardened, the tendons are anchored, transferring the pre-stress force to the concrete. This process places the concrete in a state of compression, which improves its resistance to tensile stresses. The key characteristics of a pre-stressed concrete member include:

1. Made of concrete: Pre-stressed concrete members are primarily made of concrete, which provides the bulk of the structural capacity.
2. Possesses internal stresses: Pre-stressed concrete members have internal stresses induced by pre-stressing tendons or cables, which are designed to counteract the anticipated tensile stresses resulting from applied loads.
3. May or may not be reinforced: While pre-stressed concrete members may contain reinforcement for additional strength and ductility, the primary load-carrying capacity is provided by the pre-stressing tendons.
4. Stressed after casting: The pre-stressing process typically occurs after the concrete has been cast and has partially hardened, but before it has fully cured. This allows for the tendons to be tensioned and anchored within the member.