An Empirical Method for Achieving Appropriate Aggregates Grading for Self-Consolidating Concrete by using Soil Classifying Parameters

Recently، self-compacted concrete (SCC) is extensively used in civil projects because of their special fresh and hardened properties. These properties result from numerous parameters such as the paste content، the chemical composition of paste، the aggregate volume and aggregate grading. Although aggregates are inexpensive material but they can play an important role in concrete production. An increase in the proportion of aggregate particles directly result in decreasing cement paste content that is commonly used in filling up the voids and therefore، promote the efficiency of concrete particularly its mechanical strength and durability. This work attempts to introduce a method for approaching the proper aggregate grading with lesser void volume، by determining the influence of packing density of aggregates on the properties of SCC and by using uniformity coefficient together with coefficient of gradation in soil mechanics. The obtained results indicate that there is a logic correlation between packing density، uniformity coefficient، coefficient of gradation and void volume. Also، the results verify the effect of aggregate packing density on fresh and hardened properties of SCC.