Research and statistical analysis on the impact resistance of glass fiber reinforced cement mortar containing supplementary cementitious materials

To study the failure law of supplementary cementitious material - glass fiber cement mortar (SCM-GFCM), a total of 216 specimens measuring ø75 mm × 37.5 mm were prepared with water-binder (W/B) ratios of 0.3, 0.4 and 0.5 and glass fiber (GF) volume fractions of 0%, 0.5%, 1.0% and 1.5%. In this study, the term “supplementary cementitious materials (SCMs)” specifically refers to micro-silica (MS) and expansion agent (EA) used as partial replacements for ordinary Portland cement. Dynamic impact tests were conducted using a Split Hopkinson Pressure Bar (SHPB) device at air gun pressures (P g ) of 0.2 MPa, 0.3 MPa and 0.4 MPa. The dynamic mechanical properties of SCM-GFCM specimens with different W/B ratios and GF contents were studied, and the experimental data were analyzed using a two-parameter Weibull distribution to establish the corresponding impact resistance equation. The results indicate that the failure characteristics of SCM-GFCM exhibit a pronounced strain rate effect, with the degree of fragmentation increasing with strain rate. The dynamic stress-strain curve comprises four stages, namely the elastic stage, crack expansion stage, plastic deformation stage and failure stage. As strain rate increases, the plastic deformation stage becomes correspondingly more prominent. At a given GF volume fraction, the SCM-GFCM with a W/B ratio of 0.5 is more effective in absorbing stress wave energy and thus exhibits better impact resistance. When the GF volume fraction is 1.5%, the fibers are uniformly distributed in the SCM-GFCM and demonstrate enhanced ability to resist impact damage. Furthermore, the impact resistance of SCM-GFCM can be well described by the two-parameter Weibull distribution. These findings provide valuable guidance for improving the impact resistance of mortar materials.