Influence of Mixture Proportions on Fresh and Mechanical Properties of Self-consolidating Concrete

Abstract

Self-consolidating concrete (SCC) is a concrete that able to flow and consolidate under its own weight, and it is cohesive enough to fill spaces of almost any size and shape without segregation or bleeding. In this study, workability and strength characteristics of seven SCC mixes were examined and compared with two additional vibrated mixes of normal and high strength. For this purpose, the flowability, deformability, and passing ability of fresh concrete mixes were tested through slump test, slump flow, T500, and the J-ring tests. Furthermore, the hardened concrete specimens were tested for mechanical properties with the variation in shape and size of the specimens at six different ages. The results revealed that addition of micro-silica is more effective in improving concrete workability and strength than blended micro-silica and fly ash. A well-designed SCC could have an excellent flow (730 mm) and passing ability (ΔH = 4 mm), without sacrificing the early strength (22.3 MPa in 1 day), or long-term strength (107.7 MPa in 90 days). Results also showed that the compressive strength and the tensile strength of SCC mixes were less affected by specimen shape and size compared to conventional concrete mixes.