Wet packing of blended fine and coarse aggregate

Abstract

All codified methods for measuring the packing density of aggregate are carried out under dry condition. However, these dry packing methods do not account for the effect of water in the concrete mix. In a previous study, a wet packing method for measuring the packing density of fine aggregate under wet condition has been developed and it was found that the packing density of fine aggregate can be substantially higher under wet condition than dry condition. Nevertheless, many researchers still believe that for coarse aggregate, it does not matter much whether the packing density is measured under dry or wet condition. In this study, the wet packing method was extended to measure the packing density of coarse aggregate and blended fine and coarse aggregate. The results revealed that whilst the packing density of coarse aggregate is only slightly higher under wet condition than dry condition, the packing density of blended fine and coarse aggregate is highly dependent on whether the aggregate is dry or wet. Hence, when measuring the packing density of blended aggregate, the wet packing method should always be used. © RILEM 2011.