Effect of fine aggregate/coarse aggregate ratio on the fresh and hardened properties of self compacting concrete

Abstract

This study examines the effect of the fine-to-coarse aggregate ratios on the fresh properties and mechanical properties of self-compacting concrete (SCC). The mixture design was guided to highlight the changes in the behavior of SCC in terms of; flowability, relative viscosity, stability, compressive strength, splitting strength, and flexural strength. Three ratios of fine-to-coarse aggregate were used: ratio 1; 44%: 56%, ratio 2; 47%: 53%, and ratio 3; 50%: 50%. Results indicate that the slump flow increases with the increase in the coarse aggregate content. Stability, slump flow, are relative viscosity are the key parameters that govern the behavior of fresh concrete. The ratio 47% fine to 53% coarse satisfied those parameters and recorded 680 mm slump flow with t50 equals 3.6 sec. The visual stability index was 0, which indicates the high stability of this mix. An excellent correlation (R2 = 1) was found between the viscosity index (t50) and V-funnel time (tv). The compressive strength of ratio 1 was 79.4 MPa, and slightly increased to 81.5 MPa and 83.4 MPa for ratio 2 and 3, respectively. The splitting tensile strength was found to be 8% of the compressive strength, and the flexural strength was 19% of the compressive strength for all ratios.