Strength properties of volcanic slag aggregate lightweight concrete for high performance masonry units

Abstract

The production of lightweight masonry block is in most countries a highly mechanised industry based on great automation and accuracy. This production has to match strict standards that describe properties specified for the products. These may include denotations on sizes, strength, weather resistance, insulating properties and fire resistance. Volcanic slag can be used as aggregates in lightweight concrete that meets all these requirements. In order to produce the high performance masonry units in the civil engineering applications, lightweight concrete mixtures containing the fine volcanic slag aggregate (FVSA) in reddish colour and coarse volcanic slag aggregate (CVSA) from near Manisa City, Aegean Region of Turkey were tested and the research findings were discussed in this paper. To analyse the effects of FVSA and CVSA/cement ratios on the lightweight concrete engineering properties for masonry block making, the range of different volcanic slag aggregate/cement (A/C) ratios of 5/1 to 30/1 by weight and cement contents of 41, 68, 95, 108, 135 and 162 kg/m 3 were used to make volcanic slag aggregate lightweight concrete (VSALC) mixture testing samples with a slump of from 3 mm to 5 mm. Volcanic slag lightweight blocks (VSLB) are made of volcanic slag, cement and water, which are used in construction of non-load bearing infill walls and slabs. One of the most effective ways to reduce the dead load in a multi storey building is to lighten the weight of the structure. VSLB can be manufactured from a density range of 600–1300 kg/m 3 with an average reduction in weight of 30–40% as compared to conventional slabs. They are by enabling reduction in structural cost. The experimental research findings showed that VSALC has strengths comparable to other natural lightweight aggregate concrete, yet is typically 10–20% slightly heavier. The properties, which increase in value and indicate the increasing quality with lower A/C ratios (high cement contents), are compressive strength, density and thermal conductivity. Property, which decreases in value and indicate the increasing quality, with lower A/C ratios is water absorption. In all cases, lowering the A/C ratio (higher cement content) increases quality. The research showed that high performance masonry units can be produced by the use of fine and coarse volcanic slag aggregated lightweight concrete.