Experimental and Numerical Investigation of Fracture Behaviors of Steel Fiber–Reinforced Rubber Self-Compacting Concrete

Abstract

This paper presents the experimental and numerical studies of flexural-fracture behaviors of steel fiber–reinforced rubber self-compacting concrete (SRSCC) materials. The scrap-tires rubber aggregate was used to partially (10%, 15%, and 25%) replace the fine aggregate based on its volume for SRSCC samples, and the microsteel fiber was introduced with an addition ratio of 0.2% based on the entire mixture volume. The plain self-compacting concrete (SCC) and the rubberized SCC specimens were produced for comparison. The three-point bending test on the single-edge notched beam showed the increased flexural strength and total fracture energy of SRSCC samples by adding steel fiber and rubber. The critical fracture parameters including initial fracture energy (Gf) and fracture toughness (KІc) were determined based on the Load-CMOD curves and two parameters fracture model. With these properties, the bilinear tension-softening model (aggregate interlock effect) and trilinear tension-softening model (aggregate interlock and fiber-bridging effects) were calibrated for normal SCC and SRSCC, respectively. The tension-softening functions were utilized in the FEM model to predict the flexural-fracture behaviors of corresponding specimens, and the numerical simulation results showed reasonable agreement with experiments. Overall, the experimental testing data and numerical simulation model can reveal the detailed fracture behavior of SRSCC for future improved material design.