Tensile response of ultra-high performance lightweight fiber-reinforced cementitious composite containing hollow glass microspheres at high strain rates

초록

This study investigated the effects of high strain rates on the direct tensile behavior of ultra-high-performance lightweight fiber-reinforced cementitious composites (UHP-LFRCCs) containing hollow glass microspheres (HGMs) and 1.5 % steel fibers by volume at strain rates between 0.00033 and 203 s-1. The UHP-LFRCCs with a density of 1899.5 kg/m3 and a compressive strength of 107.1 MPa demonstrated a tensile strain hardening response accompanied by multiple microcracks, even at high strain rates (184 s-1). The UHP-LFRCCs exhibited favorable rate-sensitive tensile responses, higher tensile strengths, and structural efficiencies at higher strain rates. The tensile strength and structural efficiency of the UHP-LFRCCs were measured as 10.99 MPa and 5.79 MPa/(tonf/m3) at static strain rate (0.00033 s-1) and 21.24 MPa and 11.19 MPa/(tonf/m3) at high strain rate (150 s-1), respectively. Compared with the ultra-high-performance fiber-reinforced concrete, UHP-LFRCCs produced slightly lower post-cracking tensile strength, peak toughness, and number of cracks at both static and high strain rates. The addition of HGMs significantly improved the workability, strain capacity, and tensile structural efficiency of UHP-LFRCCs.

키워드