Effect of aggregate size and grading on the failure behavior of liquid rubber-based concrete under static tension

The effect of the aggregate size and grading on the tensile strength and fracture behavior of Liquid rubber-based concrete (LRBC) are analyzed by a numerical approach. A 2D FE model was constructed in which the aggregates are represented by random distributed polygon and the interfaces are the areas surrounding each aggregate. The mechanical parameters of the rubber matrix and the bonding properties between the rubber matrix and aggregate were experimentally determined. Compressive testing of the LRBC specimens was first carried out to provide experimental benchmark for calibration of the proposed numerical model. Numerical simulations on static tension were then carried out using 39 generated specimens and the tensile stress-strain curves were obtained. It was found that with the increasing aggregate size, the tensile strength of LRBC increased steadily while the failure strain decreased. The LRBC samples with multi-grading of aggregate exhibit better mechanical properties with the higher tensile strength and larger failure strain. Based on the numerical analysis, the optimized grading design of the LRBC was recommended.