Abstract

In this study 25 different types of concrete have been produced. Pumice used as an aggregate and 0, 5, 10, 15 and 20% fly ash and each fly ash ratio has  0, 5, 10, 15 and 20% silica fume was added to replace cement. The physical and mechanical properties of concrete have been investigated. This study shows that, according to the rates of substitution compressive strength has very different characteristics. In terms of workability of concrete, an increase in the amount of silica fume substitution affects fresh concrete workability in a negative manner whereas an increase in the amount of fly ash substitution increases fresh concrete workability. No meaningful relationship is observed in concrete series in terms of surface hardness and ultrasonic transmission rate.

Key words: Lightweight concrete, pumice, silica fume, fly ash.