Influence of interface inclination angle and load impact velocity on dynamic splitting tensile behavior and dissipated energy of geopolymer-concrete composites

Abstract

The application of geopolymer has great potential in repairing damaged concrete. In engineering construction, the repaired structure is often affected by dynamic loading. Experimental research on the dynamic mechanical behavior and energy dissipation of geopolymer-concrete composites (GCC) is of great significance for understanding the bonding performance between geopolymer and concrete. In this paper, dynamic splitting experiment was performed on GCC under different interface inclination angles and load impact velocities by using the split Hopkinson pressure bar (SHPB). Then, the influence of interface inclination angle and load impact velocity on dynamic splitting tensile behavior and dissipated energy of GCC were discussed. Finally, the failure modes and strain field were analyzed based on digital image correlation (DIC) technique. The results indicate that the static peak load of GCC is roughly distributed around 26.0 kN and the dynamic peak load is 263.0 kN. The dynamic peak load measured by GCC is more than 10 times the static peak load. As the interface inclination angle increases from 0° to 90°, the dynamic peak load, static peak load and energy dissipation rate increase linearly, while the tensile sensitivity coefficient decreases. The energy dissipation ratio of GCC is kept between 0.30 and 0.40. In addition, the dynamic peak load, tensile sensitivity coefficient and dissipated energy increase gradually as the load impact velocity increases. A transition from interface failure to tensile failure can be found in GCC with the inclination angle increases.