Influence of aggregate type on the development of mechanical properties of concrete

In this study, influence of aggregate the development of mechanical properties of concrete was investigated. In the study, lightweight, and natural aggregate, crushed gravel as aggregate, fly ash and silica fume as mineral admixtures were used. Fly ash and silica fume was replaced with portland cement by weight 30 % and 10 % respectively. Splitting tensile and compressive strength, ultrasonic tests of concrete specimens that was prepared at 3, 7, 14 and 28 days were determined in constant slump (6-9 cm). The result of the study, the highest and the lowest performances was obtained in the series of concrete specimens prepared by crushed gravel and lightweight aggregates,respectively. The silica fume used as mineral admixture increased the strength of concrete that prepared using different aggregates. Silica fume increased 14 %, 12.5 %, 7.5 % in 28 days cube compressive strength of concrete as approximately that was prepared using, crushed gravel, natural aggregate and lightweight aggregate respectively. It wasn't obtained any increased in concrete series that was prepared by using 30 % fly ash. Keywords: Concrete, Mechanical properties, Aggregate, Fly ash, Silica fume VIII