Implementation and validation of Dewar’s particle packing model for recycled concrete aggregates

Abstract

This paper validates Dewar’s particle packing modelling (PPM) theory for implementing both fine and coarse recycled concrete aggregates (RCAs) from using aggregates with multi-size classes (0/1, 0/4, 2/8, 0/8, 8/20, 0/20). The voids ratios of aggregate mixtures were evaluated experimentally and compared with the predictions. The model shows high predicting accuracy for implementing coarse RCA. A size ratio adjustment factor might be necessary to calibrate the model for implementing fine RCA and all-in fractions (0/8, 0/20). A practical method for evaluating this factor is proposed. The powder within the investigated aggregates has limited impact on the estimation of the voids ratio of aggregate mixtures. However, the powder fraction shall have an effect on the final mix design as well as on the fresh and hardened concrete properties.