Characteristics of self-consolidating concrete using two types of lightweight coarse aggregates

This paper presents the development of lightweight aggregate self-consolidating concrete (SCC) using two types of lightweight aggregates having different densities. Lightweight aggregate SCC properties have been evaluated in terms of flowability, segregation resistance and filling capacity of fresh concrete as per the standards of the Japanese Society of Civil Engineering (JSCE). The measurement of the mechanical properties of hardened lightweight aggregate SCC, including compressive strength, splitting tensile strength, elastic moduli and density, as well as its specific strength were also carried out. The characteristics of lightweight aggregate SCC at the fresh state showed that as the density of the lightweight coarse aggregate decreases, the flowability improves but the segregation resistance tends to decrease. The 28-days compressive strength of the lightweight SCC was found to be 32 MPa or higher. The relationship between the compressive strength and the splitting tensile strength was found to be similar to the expression presented by CEB-FIP, and the relationship between the compressive strength and the elastic moduli was found to be similar to the expression suggested by ACI 318-05 which takes into consideration the density of concrete. The density of the lightweight aggregate SCC decreased by up to 14% compared to that of the control SCC, and the specific strength decreased by up to 20%.