Effect of Supplementary Cementitious Materials on the Mechanical and Physical Properties of Lightweight Concrete

Abstract

The effect of different amounts of supplemental cementitious materials (SCMs) on the physical and mechanical characteristics of lightweight concrete is examined in this study. SCMs include Fly Ash, Rice Husk Ash (RHA), Ground Granulated Blast-furnace Slag (GGBS), and Silica Fume. Cube crushing strength, flexural strength, density and water absorption tests were performed on eight mix proportions. The current study also established that, when 20% Fly Ash was incorporated in the concrete as a replacement, the compressive strength was 30 MPa and the flexural strength was 4 MPa, the highest compressive strength of 32 MPa and the flexural strength of 4.2 MPa were however obtained when 20% Silica Fume was incorporated in the concrete as a replacement. In the present study only small increment in water absorption was recorded for mixtures containing GGBS and RHA while Fly Ash and Silica Fume shown relatively less water absorption than the control specimen. So, according to the results obtained Fly Ash and Silica Fume are good additives to lightweight concrete since the material becomes more stronger and durable and at the same time has low density.

Keywords

• lightweight concrete
• fly ash
• rice husk ash
• ggbs
• silica fume
• compressive strength
• flexural strength
• water absorption
• density
• supplementary cementitious materials