• Radhey Ramesh Yadkikar
• Prof. Pankaj A. Autade

Structures are assemblies of load carrying members capable of safely transferring the superimposed loads to the foundations. Their main and most looked after property is the strength of the material that they are made of. Concrete, as we all know, is an integral material used for construction purposes. Thus, strength of concrete used, is required to be ‘known’ before starting with any kind of analysis. In the recent past, various methods and techniques, called as Non-Destructive Evaluation (NDE) techniques, are being used for Structural Health Monitoring (SHM). The direct determination of the strength of concrete implies that concretespecimens must be loaded to failure. Therefore, the determination of concrete strength requires special specimens to be taken, shipped, and tested at laboratories. This procedure may result in the actual strength of concrete, but may cause trouble and delay in evaluating existing structures. Because of that, special techniques have been developed in which attempts were made to measure some concrete properties other than strength, and then relate them to strength, durability, or any other property. Some of these properties are hardness, resistance to penetration or projectiles, rebound number, resonance frequency, and ability to allow ultrasonic pulses to propagate through concrete. Concrete electrical properties, its ability to absorb, scatter, and transmit X-rays and gamma rays, its response to nuclear activation, and its acoustic emission allow us to estimate its moisture content, density, thickness, and its cement content. However, the term “nondestructive” is given to any test that does not damage or affect the structuralbehavior of the elements and also leaves the structure in an acceptable condition for the client.

Non Destructive Testing , Structural Audit, Compressive strength ,Structural Health Monitoring., Rebound Hammer ,Ultrasonic Pulse Velocity.

" Structural Audit of Buildings by NDT Methods", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 2, page no.172-176, February-2019, Available :http://www.jetir.org/papers/JETIRAE06039.pdf

" Structural Audit of Buildings by NDT Methods", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 2, page no. pp172-176, February-2019, Available at : http://www.jetir.org/papers/JETIRAE06039.pdf