Effect of coarse aggregate blending on short-term mechanical properties of self compacting concrete

This investigation is mainly focused on finding the unit weight, compressive strength, modulus of elasticity (MOE) and splitting tensile strength (STS) of SCC mixes with different coarse aggregate blending (60:40 and 40:60) (20 mm and 10 mm) and coarse aggregate content (28% and 32%) and these properties were compared to a conventional concrete (CC). All SCC mixes had 35% replacement of cement with class F fly ash. The coarse aggregate blending did not affect the compressive strength of SCC mixes, but it affected the unit weight, MOE and STS of SCC mixes. A new parameter called coarse aggregate points (CAPs) has been introduced to study the effect of coarse aggregate blending in a particular coarse aggregate content on mechanical properties of SCC mixes. It is observed that for the given strength, SCC mixes with the same CAP value have shown similar mechanical properties. The measured MOE of all mixes were compared with ACI 363R and AASHTO LRFD/ACI 318 predicted equations. The measured STS of all mixes were compared with ACI 363R and CEB-FIP predicted equations.