Investigation of the effect of difference in particle size of some pozzolinic materials used in mortars on alkali-silica reaction and pressure strength

In this research, the effect of the particle size of mineral additive used as some pozzolanic substance on the alkali silica reaction (ASR) of the concrete mortar was investigated. In this context, Soma thermal power plant bottom ash (floor ash) and Gördes zeolite were grinned using five different grinding times (0, 30, 60, 180 and 240 min) and a mineral additive with five different particle size was obtained. Concrete mortars were prepared by substituting respectively 10%, 20 and 30 of cement from each particle size additive. The natural thin aggregate and CEM-I 42.5 cement taken from Doğancık village (Sultandağı / Afyonkarahisar) stream were used as aggregate in the preparation of mortar. Percent expansion values of the mortars resulting from ASR were determined by accelerated mortar bar method according to TS 13517. As a result of the studies, the best results for suppressing alkali silica reaction and preventing expansion for bottom ash, 240 min. (d50:16,79 µm) obtained with a 30% substitution of the product obtained. This product, according to the mortar produced without additive, decreased the rate of expansion by 85,86% and compressive strength did not cause a significant decrease (2.45%). In the studies with zeolite, the best result was obtained with a 10% substitution of the product obtained at the grinding time of 240 min (d50:16,79 µm). The decrease by ~ 98% in the expansion compared to those prepared with mineral additive, but in the pressure strength the decrease by ~29% was determined in the mortars produced with 10% substitution of zeolite.