Shrinkage and the development of mechanical properties in rendering mortars

Abstract

This research discusses shrinkage and the development of mechanical properties in mortars made of cement, lime and sand 1:1:6 (volume), and in compositions with varying content of lime. Technology innovation was sought for in what concerns laboratory tests similar to real rendering conditions. The tests have been carried out in plaque specimens 15 and 25 mm thick. Factors such as mortar composition, water absorption through the basis and mortar/basis adherence, have been taken into account when analysing shrinkage in 400 mm x 150 mm specimens, as well as flexural strength and elasticity modulus. The mechanical tests have been carried out in plaques 200 mm x 75 mm, and the displacement in the centre of the specimen has been measured during loading for calculating elasticity modulus. The porosity of mortars has also been observed through the technique of mercury intrusion. The set of tests in the research showed the importance of laboratory simulation of real rendering conditions.