The effect of chemical and mineralogical composition of aggregates on tensile adhesion strength of tiles

The fundamental requirement of the tile adhesive mortar is its adherence and durability. The properties of adhesives are affected by the chemical and mineralogical composition of the aggregates. The aggregates are obtained from the leading 10 companies that sell adhesives. First, chemical compositions of aggregates are determined from chemical analysis by XRF. Then, exact mineral compositions of aggregates determined from the chemical compositions by using CIPW norms. Aggregate size and granulometry is determined by microscope analysis. Ten different groups of dry-mixed adhesive samples are prepared for testing from the 10 different aggregate mixtures that are obtained from producing companies. Dry, wet, hot and freezing-thawing adhesive strengths are determined according to European EN 1348 and EN 12004 standards. The mineral and chemical composition of aggregate type that gives the highest adhesive strength is determined. It is found that the highest pull-out adhesive strength was obtained on samples those aggregates have high content (80-95%) of SiO2 and with small amount (0.5-3.4%) of CaCO3.