Experimental investigation on the high-volume fly ash ecological self-compacting concrete

As an innovative high-performance concrete, high cementitious material content of Self-compacting concrete (SCC) results in high cost and environmental burden, which limits its application. This paper proposed an innovated mix proportion design method to prepare an ecological self-compacting concrete (Eco-SCC) with more coarse aggregates and higher fly ash (FA) content to reduce the environmental impacts of SCC. The packing ratio (P-R) of coarse aggregate, FA content and sand volume ratio of Eco-SCC were optimized, and their influences on the permeability and drying shrinkage ratio were investigated. The optimal mix proportion of Eco-SCC was determined with coarse aggregate P-R of 0.6, FA content of 30% and sand volume ratio of 0.48, which has better mechanical properties, lower shrinkage ratio and lower porosity compared to conventional SCC. The high-volume FA Eco-SCC, of which the cement amount was 285 kg/m(3) (cementitious materials amount was 475 kg/m(3)) can reach a higher strength grade with less cementitious materials than conventional SCC, and its 28d and 90d compressive strength are 64 MPa and 74.9 MPa, respectively. Comparing with conventional SCC, the high-volume FA Eco-SCC costs less on raw materials and construction with less environmental impact, which makes it a promising widely used high-performance concrete.