Passing ability and segregation stability of self-consolidating concrete with different aggregate proportions

Abstract

An extensive experimental programme has been carried out to study the effects of fine:10 mm:20 mm aggregate proportions on the passing ability and segregation stability of self-consolidating concrete. A total of 18 trial concrete mixes with water/cementitious materials ratios ranging from 0·30 to 0·36 and different combinations of fine and coarse aggregates were produced. In each mix, the paste volume was set at 35%, and pulverised fuel ash, condensed silica fume and a third-generation superplasticiser were added at dosages of 25%, 5% and 3% respectively. All the mixes were tested to have slump flow well above 700 mm. However, not all have satisfactory passing ability and segregation stability, as revealed by J-ring, U-box and sieve segregation tests. The cohesiveness and coarse aggregate content appeared to be the major factors as the passing ability and segregation stability were generally better for mixes with higher cohesiveness and lower coarse aggregate content. Nevertheless, some of the mixes may be considered for making high-strength, self-consolidating concrete. They have the common characteristics of 20 mm aggregate content ≤ 10 mm aggregate content and coarse aggregate content ≤ fine aggregate content.