Impact of particle packing mix design method on fracture properties of natural and recycled aggregate concrete

Abstract

The fracture properties of four types of concrete prepared using natural coarse aggregate and recycled coarse aggregate and conventional and particle packing method (PPM) of mix design approaches are studied. The three-point bending (TPB) test is performed using three different sizes of single edge notched beam. The fracture energy is calculated from the load-CMOD curve obtained in the TPB test, and in this process the load-CMOD curve is curtailed at 2% of the depth of the beam. Based on CTODc and w1 relationship, appropriate softening function is used to estimate the double-K fracture parameters. The fracture energy and fracture toughness parameters of recycled aggregate concrete (RAC) is inferior to the natural aggregate concrete (NAC). The PPM mix design improves the fracture properties of concrete in comparison to the conventional mix design approach. The fracture properties of PPM mix designed RAC are comparable to that of NAC prepared using conventional method.