Evaluation of Concrete Core Testing & Pile Rafts and Compensated Pile Rafts

Abstract

Concrete, being the most widely used material in modern structures worldwide. It performs a very significant role in givingstrength tostructure when combined with reinforcement. However, poor workmanship, workability & material may cause adverse effect to the concrete & strength may not pertain to the design specifications. Therefore, forensic investigation is carried out to quantify the deterioration in concrete for which Non-Destructive Testing (NDT) in combination with core extraction may be carried out. For the aforementioned reason, cores are extracted from the suspected members of the structure without damaging the reinforcement & results are compared with their respective design strength obtained from cylinders casted at the time of pouringof concrete. During extraction & testing process of the cores, it might not depict the actual strength of concrete due to the stresses developed in concrete while thecore is extracted, core’s diameter, length to diameter proportion, direction of core extraction etc. An objective of this research is to establish a model to correlate the actual strength of cores with cylinder casted at 28days & cores extracted from the respective specimens with variation in diameter, aggregate size & strength of concrete. But there is anunreliability factor as different Codes have different guideline & provisionsfor the different correction factors. We’ll take a deep look into different codes provisions.