Ultrasonic pulse velocity testing for monitoring the degradation of infill masonry walls and access their impact on the durability of the envelope of buildings with reinforced concrete structure

Abstract

Buildings with reinforced concrete structure (RCS buildings), including unreinforced masonry (URM) infill walls, can be negatively affected by anomalies in their envelope, such as cracking and water penetration, which worsen the aesthetic aspect and reduce the safety and level of comfort of those buildings. To access the relevance of these anomalies and their evolution along service life, a corresponding survey and monitoring during service life are essential. Non-destructive test methods (NDT), in particular ultrasonic pulse velocity (UPV) testing, are currently used in that survey and monitoring. In the context of monitoring the degradation of the URM infill walls and access their impact on the durability of the RCS building envelope, UPV testing can be a type of NDT method to be used, considering that it can contribute to the evaluation of the state of conservation of the construction elements, such as masonry and concrete. It is intended here to access the potential use of UPV testing in the monitoring of anomalies related to the degradation of building facades due, particularly, to cracking and to water penetration associated with WDR (wind driven-rain). The preliminary assessment of the use of UPV testing is made through the previous analysis of the results of the application of UPV testing for the detection of sub-surface and surface cracking in compression tests of masonry specimens. Following that analysis, an evaluation is made of the conditioning aspects of the use of UPV testing to access durability problems of the building envelope. Particularly, the main characteristics of cracking with interest for the assessment of the potential use of UPV testing are generally discussed. And, finally, an evaluation is made of the risk of water penetration through the cracks, for potential use of UPV testing in monitoring the presence of humidity in the cracks.