Fig. 11 shows the average strength vs. water cement ratio for the different aggregate types, collated and averaged disregarding the proportion of fine aggregate to total aggregate content. From the average results of strength vs. water cement ratio for different aggregate type it is clear that quarry dust record higher strength compared to other aggregate types. Quarry dust recording higher strength than all other aggregate types is further confirmation of the less sensitivity of particle size distribution and packing on the properties of SCC. Fig. 12 shows strength vs. w/c ratio for the three aggregate types for normal concrete and self-compacting concrete (Alluthwatta AGHD et. al (2011)). Results indicate that SCC has always produced higher strength than normal concrete. It is also seen that, unlike in the case of normal concrete where offshore sand produced higher strength,in SCC, quarry dust has produced the highest strength. It is also seen the margins of differences of the recorded strength between different aggregate types have narrowed down considerably for the SCC. For normal concrete, it is evident from the higher water demand that mixes with quarry dust as fine aggregate
is most difficult to workwith (Rajapaksha RWCN et.al (2009). However, there is marked contrast of its performance as fine aggregate of SCC. Lower water demand for quarry dust compared with river sand mixes and the highest recorded compressive strength for quarry dust mixes are indications that viscosity modified self-compacting concrete have largely eliminated the influence of fine aggregate due to particle size distribution and aggregate packing.