关键词: 珊瑚砂水泥胶结体, 细颗粒, 颗粒团聚, 冲击压缩性能, 分离式霍普金森压杆试验

Abstract: This article used a split Hopkinson pressure bar to conduct impact compression tests on cemented coral sand (CCS) at different strain rates, studying the impact compression performance of CCS containing fine particles and the influence of particle agglomeration on material mechanical properties. The experimental results show that, macroscopically, the dynamic compressive strength of CCS increases first and then decreases with the increase of fine particle content, and reaches its maximum value at 3% (mass fraction). As the degree of agglomeration deepens, the dynamic compressive strength of CCS gradually decreases. Microscopic analysis through mercury intrusion porosimetry reveals that the addition of a small amount of fine particles reduces the porosity and harmful pores of CCS, resulting in an increase in the macroscopic compressive strength of CCS. However, excessive fine particles are prone to agglomeration, leading to a decrease in the bonding strength of the interface transition zone, which can easily cause cracks and reduce material toughness and dynamic strength. By analyzing the dynamic growth factor of CCS and the relationship between specific absorption energy and strain rate, it is found that the dynamic growth factor has a significant strain rate effect. A small amount of coral sand particles can enhance the absorption energy of CCS, and there is an approximate linear relationship between specific absorption energy and strain rate.

Key words: cemented coral sand, fine particle, particle agglomeration, impact compression performance, split Hopkinson pressure bar test