Influence of fineness of volcanic ash and its blends with quarry dust and slag on compressive strength of mortar under different curing temperatures.

In this study researchers investigated the influence of fineness of locally available basaltic volcanic ash (VA) and its blend with other potential supplementary cementitious materials (SCMs) on compressive strength of mortar. Local quarry sites and steel making industries in the eastern province of Saudi Arabia produces tons of wastes commonly known as quarry dust (QD) and electric arc furnace slag (EAFS), respectively. Including the CM, a total of 19 mortar mixtures were prepared by substituting cement with various SCMs (VA, FA, QD, EAFS), their different percentages in binary mixes, fineness of VA, and blends of ultra-fine VA with other SCMs (ternary and quaternary). After casting, specimens were subjected to different curing temperature (20, 40, and 60 °C) and moisture conditions (continuous and partially moist). Compressive strength was measured according to ASTM C 109 at ages 7, 28, and 91 days and an average value of three identical 50-mm 3 specimens was reported. The test results indicated that improved fineness of VA up to 30% mass replacement of cement demonstrated compressive strength comparable to control and reference FA mortars at all ages particularly under high curing temperatures. Moreover, a quaternary blend of ultra-fine VA (20%) with EAFS (10%) and QD (10%) produced strength higher than all other ternary and quaternary blends at all ages and comparable 91 days strength to control mortar. [ABSTRACT FROM AUTHOR]