The construction of coral island reef project is of great strategic significance to protect national marine rights and interests. With the development and construction of marine resources, the preparation of concrete with coral aggregate has been widely used in island and reef engineering. The research on its basic mechanical properties and engineering application has also become one of the current hot topics. In order to explore the influence of sand binder ratio on the dynamic mechanical properties of seawater mixed full coral aggregate concrete, the variation laws of failure mode, dynamic compressive strength, dynamic elastic modulus and toughness index of specimens with different sand binder ratio (0.8—1.2) under different strain rates were analyzed based on Hopkinson compression bar test. The results showed that the dynamic compressive strength increased with the increase of sand binder ratio. When the strain rate was 120 s-1, the increase proportion of dynamic compressive strength was 6.7%. The variation law of dynamic elastic modulus was consistent with the change of strength, which increased with the increase of sand binder ratio. When the strain rate was greater than 80 s-1, the increase proportion reached 24.1%. The toughness index and relative toughness index increased with the increase of sand binder ratio. When the sand binder ratio increased to 1.2, the increase proportion was 13.4% and 37.8% respectively. In addition, through the analysis of specimen failure mode, when seawater mixed all coral aggregate concrete was subjected to the same impact load, there was little difference in specimen failure at low strain rate. Under high strain rate, the higher the sand binder ratio, the lower the damage degree of concrete. It can be seen that the increase of sand binder ratio will certainly improve the impact resistance of seawater mixed all coral aggregate concrete, resulting in the improvement of impact resistance, ductility and compressive strength. © 2023 Cailiao Daobaoshe/ Materials Review. All rights reserved.
