Effects of Fines Content and Type, and Coarse Aggregate Size on the Workability Properties of Self-Compacting Concretes

Abstract

Self-compacting concretes (SCC) were prepared with 10 mm and 16 mm coarse aggregate sizes and using limestone powder (LS) and fly ash (FA) as fine material. The amount of fines in concrete, where the amount of cement and the water / cement ratio were kept constant, was increased in 36 dm3 increments up to 108 dm3 . The effect of the type and amount of fines and coarse aggregate size on flowing, passing, segregation and blocking properties of SCCs were examined. Experimental results indicated that slump flow increases with increasing fines content. Opposite to this, V-funnel times increased with increasing fines content, however, they were shorter for FA than those of LS, which can be attributed the balling and lubrication effect of the former and arching effect of the latter particles. For both fines, higher segregation was obtained for SCCs with 16 mm than those of 10 mm. The SCCs with low amount of fines displayed higher blocking step in general and FA-added concretes had higher segregation than those of LS. The difference in the behaviors of LS and UK added concretes is most probably due to the differences in the particle shape and surface properties.