Microstructural characterization of aged mortar by destructive and non-destructive testing

Abstract

Degradation of concrete structures located in high humidity atmospheres or under flowing water is a very important problem. In this study, microstructure of several samples of aged mortars has been characterized. For this purpose, destructive and non-destructive testing has been used, and results obtained with both methods correlated. Mortar ageing has been accelerated by immersing the samples in ammonium nitrate solution. Destructive tests of porosity, thermal analysis, scanning electron microscopy and x-ray diffraction have been done, in order to characterize the microstructure of aged mortar and the degradation of cement matrix. Furthermore, non destructive characterization was done, using ultrasonic velocity measures. With both characterization methods, cement matrix degradation has been characterized and promising results have been obtained with a view to obtain a non-destructive method to characterize mortar degradation.