Mariano GONZÁLEZ CORTINA and Luis de VILLANUEVA DOMÍNGUEZ Polytechnic University, Madrid

The aim of this research is to obtain hydraulic mortars, from aired lime activated with chamotte or burnt clay powder. This chamotte comes from the ceramic industry waste. The purpose is to add hydraulic properties to lime, as well as to obtain hydraulic mortars with significantly improved mechanical properties. In order to achieve this, several types of chamotte obtained from clay burnt at different temperatures and with various granulometries have been tried out. Several mortars varying the proportions of lime, sand and water have been tested. For every test, a double series of test pieces have been prepared to be stored and cured at room temperature or water immersed. Shore C, mechanical flexural strength, and compressive strength tests have been performed. Later, X-ray diffraction analysis has been carried out to determine qualitatively the composition of the crystalline structure, as well as the microstructure using stereomicroscopy and electronic microscopic sweeping with X-ray microanalysis. As a conclusion of the research done, several types of mortars with different proportions have been formulated. Those mortars with their characteristics make them valid GRIP mortars for brickwork for restoration work and for new construction work.