In situ techniques for the characterisation of rendering mortars

Abstract

Compressive strength, porosity and two "in situ" techniques (ultrasonic velocity and rebound hardness test) are used for the characterisation of several aerial, hydraulic lime-based and cement-based mortars. Prismatic specimens and mortars applied as a brick render are used for the characterisation. A comparative analysis of the "in situ" test results and compressive strength is performed and the relationship between porosity and ultrasound velocity is analysed. A satisfactory relationship between the porosity and ultrasound velocity values is found and this indicates the possibility of estimating porosity from ultrasound velocity. The relationship between ultrasound velocity, rebound values and compressive strength emphasizes the potential of the "in situ" test methods for characterisation of mechanical properties of mortars. © RILEM 2012.