DETERMINATION OF ALKALI-SILICA REACTION EFFECTS OF ZEOLITIC TUFF ADDITION ON THE DIFFERENT AGGREGATES

The aim of this study is to determine the alkali-silica reaction (ASR) related characteristics of crushed stones that are produced from rocks of perlite, andesite and limestone when zeolitic tuff (ZT) is used in the mortar mix as cement replacement in different ratios. Accelerated mortar bar experiments in accordance with ASTM C 1260 were carried out on crushed stone aggregate samples to determine the ASR. CEM I 42.5 R type cement was replaced by ZT material in the following ratios: 0, 10, 20, 30 and 40%; in order to investigate the effects of replacement on the ASR pertaining to the aggregate types, 45 mortar bar pieces were produced. The length change values of the samples were measured on the 3, 7, 14, 28, 42, 56 days according to the accelerated mortar bar method. Measured length changes for the control samples on 14(th) day were found to be 0.570% at the level of potentially harmful for perlite, 0.101% at the level of critic for andesite and 0.061% at the level of harmless for limestone. Length changes at the harmful levels were taken under control for perlite at 30 and 40%, for andesite at 20, 30 and 40% ZT replacement ratios. Length change values of all samples decrease as ZT replacement increases. As a result, ZT replacement is effective to suppress the ASR of reactive aggregates.