DIAGNOSIS OF THE CONDITION OF A CONCRETE BY NDT TECHNIQUES

Abstract

Before any repair, we must a deep diagnosis with non-destructive techniques, to we can repair a concrete element(the substrate) in order to choose the most compatiblematerial and have a durable repair. In our work we areinterested in determining the physical and mechanicalcharacteristics (compressive strength, modulus of elastic-ity) of an old concrete, these characteristics are deter-mined by using both sclerometer and ultrasounds. We usedseveral steps in order to characterize 10 cylindrical speci-mens of a (16x32) cm aged over 2 years, where 6 preparedon site and 4 in the laboratory. The compressive strength isdetermined by a combined method of sclerometer andultrasounds, based on 3 different mathematical formulascombining sclerometer and U.S. The modulus of elasticityis calculated using the speed of sound, density and BAEL91 rules. After analyzing and comparing the resultsobtained from different values of compressive strength,modulus of elasticity and density, it was observed a signif-icant difference between the values of modulus of elasticitycalculated from ultrasounds and those determined byBAEL 91 rules.