Assessment of statistical variations in experimental impact resistance and mechanical properties of silica fume concrete

Silica fume as a new supplementary cement has several eects on initialmechanical characteristics and long term improvements. in this paper, the impactresistance and mechanical properties of concrete mixed with silica fume are statisticallyinvestigated by selecting 288 specimens in three mix designs. zero, 7% and 14% ofportland cement by weight were replaced by silica fume in silica-fume mixtures. twenty100  100  100 mm cubic specimens, twenty 100  200 mm cylindrical specimens, twenty60  80  320 mm specimens and thirty-six 150  64-mm discs were cast from each batchto prepare specimens for dierent test purposes. cubic and cylindrical specimens wereused to determine compressive strength, and prismatic specimens were tested to obtaintensile rupturing. also, cylindrical cutting specimens were subjected to a drop-weighttest, following aci committee 544, to determine the impact strength of mixed concrete.experimental data on the mechanical properties of the dierent mixes indicated thatsilica fume improves mechanical properties and impact resistance, while statistical analysisundertaken based on these experimental tests showed a reduction in the coecient ofvariation values. in other words, adding silica fume improves the statistical dispersion ofdata