اثر دوده سيليسي بر مقاومت و نفوذپذيري مخلوطهاي بتن غلتكي سدسازي با خمير سيمان كم تا متوسط

The Effect of Silica Fume on Strength and Permeability of RCC Mixes with Low and Medium Paste Content

Non production of PFA and the non uniform quality of natural pozzolans is a potential obstical in production of concrete mixes for RCC dam construction in Iran. Another option that can be considered is utilization of a super pozzolan called silica fume, which is available in the country as a byproduct offerrosilicon industries. A laboratory investigation to evaluate the effect of incorporating various dosages of silica fume on enhancing the quality of RCC mixes of low to medium pastes (80 and 110 Kg/m^3 cementitious materials contents), was carried out. The results show that incorporation of silica fume causes significant improvements in compressive and tensile strength of RCC mixes. The improvements observed in strength, Ranged from 25 to 60 percent for 5 td 15 percent cement replacement by silica fume. Permeability tests carried out also show that, a significant reduction in permeability is achieved by utilization of silica fume in RCC mixes.