Evaluation of Shear Bond Strength between Repair Materials and Substrate Concrete

Abstract

Nowadays, application of adding a fresh concrete layer (Overlay) to a hardened one (Substrate) has been used widely as a main in mass concrete, concrete replacement, and concrete jacketing. Deterioration of concrete structures usually begins at the surface of structural members, and progresses into the structure. The most common strengthening technique is adding a new concrete layer to increase the member effective size. Bond tests between repair materials and substrate concrete have been developed for several specific applications. Till now there is no consensus among practitioners for evaluating the bond strength under a shear state of stress that is commonly encountered in concrete structures. It is simple to carry out tension bond test in situ or in laboratory than shear bond test. The main aim of this work is to try to find out correlations between tensions and shear bond tests. The main objective of the experimental program is to evaluate the tension and the shear bond strength between substrate concrete and overlay repair materials, and to find correlations between shear bond strength and tension bond strength. Several parameters were adapted to evaluate the bond strength