Short and long-term properties of silica fume high strength mortar

Silica fume CS.F) is a waste material that is produced during theproduction of silicon and silicon alloys; it is a relatively new constructionmaterial. The use of a new civil engineering material needs one to know itslong-term behavior, or feeling this, to have a reliable way of predicting it, atleast for the anticipated life ofthe structure.General agreement does exist on the short-term behavior of the Silicafume concrete, but most information is needed about its long-term behavior.The main objective of this study is to take pales towards this goal throughthe long-term behavior of silica fume high strength mortar.Nine mixes were used in this study; a plain mortar mix taken as areference mix, four mortar mixes containing Silica fume as a partialreplacement of the cement content, and four mortar mixes containing Silicafume as an addition to the mix proportions. The used percentages of Silicafume as a replacement or addition were 5, 10, IS, and 20 %. In all mixes thewaterlcementitious and sand/cementitious ratios were kept constant of 0.4and 3.0, respectively.Three kinds of tests were used to investigate the Silica fume highstrength mortar mechanical properties; compressive strength, indirect-tensilestrength, and tlexural strength tests.The short-term properties were measured at ages of 7, 28, and 56 days.The short-term specimens were cured in 100% relative humidity at roomtemperature till tested.The long-term properties were obtained by usmg the acceleratedageing procedure. The specimens were cured for 28 days in 100% relativeXfII