Dynamic splitting tensile properties of crumb rubber modified ultra-high performance engineered cementitious composites (UHP-ECC)

Ultra-high performance engineered cementitious composites (UHP-ECC) have been extensively researched as a promising material to evaluate their mechanical properties under quasi-static loads. However, further comprehensive research is necessary on their dynamic mechanical response at high strain rates. This paper systematically investigates the dynamic tensile mechanical properties and failure mechanisms of rubber-modified UHP-ECC. Dynamic mechanical tests were conducted using a split hopkinson pressure bar (SHPB) to obtain crucial dynamic mechanical parameters, including dynamic splitting tensile stress, dynamic increase factor (DIF), and energy absorption capacity for different UHP-ECC samples. It was observed that CR acts as pseudo-pores, enhancing the deformation capacity of the specimens at high strain rates. At high strain rates, CR reduces the stiffness of the matrix and the bond strength of the fibres, making a 5 % CR content more beneficial for improving the splitting toughness and energy absorption capacity of UHP-ECC. The findings of this study are significant for guiding infrastructure construction using CR modified UHP-ECC under high-velocity impact.