Mechanical and fiber/matrix interfacial behavior of ultra-high-strength and high-ductility cementitious composites incorporating waste glass powder

Most of the waste glass is landfilled, which is not conducive to the sustainability of the environment. However, waste glass powder (WGP) with sufficient fineness and high alkali reactivity exhibits excellent pozzolanic behavior, promoting its potential application in the concrete industry. This work evaluated the feasibility of replacing cement with WGP ranging from 0 to 30% to produce Ultra-High-Strength and High-Ductility Cementitious Composites (UHS-HDCC). The influences of WGP on the fresh flowability, mechanical properties, and fiber/matrix interfacial behavior of UHS-HDCC were investigated. The introduction of WGP enhanced the flowability of fresh UHS-HDCC mixtures. UHS-HDCC incorporating 10% WGP achieved incredible compressive strength, ultimate four-point bending stress, and ultimate uniaxial tensile stress, reaching around 158.4 MPa, 43.22 MPa, and 12.47 MPa, respectively. Moreover, all UHS-HDCCs exhibited strain-hardening features and multiple cracking behaviors. The maximum mid-span deflection and ultimate tensile strain capacity of UHS-HDCCs with WGP were distributed in 9.84 mm–13.83 mm and 5.88%–7.47%, respectively. Compared with WGP0, WGP10 and WGP20, the crack distribution in the WGP30 was more saturated and the number of narrow cracks was the largest. The results of the single-fiber pullout test indicated that the interface frictional bonding stress of WGP10 was reached 2.22 MPa, which represented a high ultimate four-point bending stress and ultimate uniaxial tensile stress. Furthermore, the average slip hardening coefficient of UHS-HDCCs ranged from 0.0032 to 0.0041. Based on the micromechanical model, the fiber ruptured fraction of WGP10 in the development of crack opening was calculated to reach 31.5%, which explained the decrease in maximum mid-span deflection and tensile strain capacity. Therefore, the experimental research will provide preliminary data for the scientific and efficient use of waste glass in engineering construction.