Packing density measurement and modelling of fine aggregate and mortar

Abstract

A newly developed wet packing method has been applied to measure the packing densities of blended fine aggregates (each a mixture of fine aggregates of different sizes) and mortars (each a mixture of cement and blended fine aggregate) under the wet condition, with or without superplasticizer added, and with or without compaction applied. For the blended fine aggregates, the conventional dry packing method has also been employed to measure their packing densities under the dry condition and the results show that the packing density of fine aggregate is generally higher under wet condition than under dry condition. For both the blended fine aggregates and mortars, the measured packing densities have been compared to the predicted packing densities by two existing packing models. Good agreement between the measured and predicted packing densities has been achieved with the mean absolute error being 2.1% for the blended aggregates and 1.1% for the mortars. This is the first time that the packing densities of mortar samples are directly measured and compared to predictions by packing models to verify the applicability of the wet packing method and the packing models.