Book Description
Reinforced and pre-stressed concrete are widely used for the construction of infrastructures such as bridges, industrial structures, buildings, etc. Most of the time, the quality of the concrete mix is assumed to be guaranteed but due to the congestion of reinforcement and the quality control exercised during placing and vibrating, honeycombs and voids are likely to be present in the hardened concrete. The presence of voids leads to the early deterioration of concrete and corrosion also sets in. The corrosion of reinforcement causes damage to the cover concrete and also section loss in the area of steel. In the case of pre-stressed concrete members, the corrosion leads to a catastrophic failure without any warning. Hence, it becomes necessary to evaluate the condition of concrete using Non Destructive Techniques (NDT) and Partially Destructive Techniques (PDT). The Ultrasonic Pulse Velocity (UPV) method which is widely adopted till now gives the relative quality and integrity of concrete and is based on the transit time. The rebound hammer gives the quality of concrete in the cover zone based on the rebound number.