Effect of hydrophobisation on durability related properties of ceramic brick

The article describes the issues of resistance hydrophobised ceramic bricks. The purpose of the research was to evaluate the possibility to apply organosilicone based hydrophobising preparations for impregnation of ceramic building materials. Within the experiment the efficiency of three preparations which differed in hydrolytic polycondensation grade, viscosity and product concentration was checked main factors influencing the final effect of the hydrophobising procedure. The capillary-porous structure of bricks makes them sensitive to water influence. Therefore, a detailed analysis of heat parameters in relation to moisture was required. The following laboratory tests were performed: the basic physical properties, water flow due to capillary forces, water permeability, contact angle and surface free energy, thermal conductivity, resistance to salt crystallization, frost resistance, silicon resin distribution in the micro-structure of a ceramic bricks. The moisture changes influence on thermal conductivity coefficient in non-impregnated and hydrophobised bricks were analysed and verified. The analysis of moisture parameters and moisture transport was executed using a constant monitoring time domain reflectometry (TDR) method. The fine molecule compounds of alkyl-alkoxy-silanes provide the highest resistance of ceramic brick.