Mechanical properties of ecological high ductility cementitious composites produced with recycled crumb rubber and recycled asphalt concrete

Ecological high ductility cementitious composites (ECO-HDCC) produced with recycled crumb rubber (RCR) and recycled asphalt concrete (RAC) were developed for the purpose of achieving highly ductile materials with effective engineering cost and environmental burden. Mechanical performance factors such as tensile, compressive, flexural behaviors and fracture toughness of ECO-HDCC were investigated. In addition, fiber dispersion, scanning electron microscopy and X-ray computed tomography tests were performed to reveal the mechanical performances of ECO-HDCC. Results indicate that the contributions of limited contents for RCR as well as RAC to fiber dispersion are beneficial. Adverse effects on mechanical performances of ECO-HDCC are observed as RCR or RAC content increases. The tensile ductility, flexural deflection and ductility indexes of ECO-HDCC increase as RCR or RAC content increases. Strength loss of ECO-HDCC can be attributed to recycled aggregates with low stiffness, which results in high porosity of ECO-HDCC. In addition, low matrix strength can positively affect the fiber bridging capacity, resulting in higher tensile ductility, flexural strength and fracture toughness.