Coral sand is one kind of the important building materials in coral reef engineering practice. The use of cement as a stabilizing agent can significantly improve the mechanical properties of coral sands and is widely applied in the subbase engineering construction in coral reef islands. Cement-stabilized coral sand structures may contain high contents of fine coral particles and salinity because of the high crushability of coral sands and the existence of seawater surrounding them. In this study, the effects of coral sand powders and seawater salinity on the dynamic mechanical properties of cemented coral sand (CCS) were investigated through the split Hopkinson pressure bar (SHPB) tests and Scanning Electron Microscope (SEM) analysis. It was found that the strength (i.e., the peak stress) of CCS specimens increased firstly and then decreased with the increase of powder content. The specimens reached the maximum peak stress when 3% powder content was included. The initial improvement of CCS strength was attributed to the pore-filling effect of coral powders, namely, the micro pores of the CCS specimens could be more effectively filled with higher percentages of coral powders being used in the experiments. However, excessive coral powders resulted in the reduction of specimen strength because these powders could easily be cemented into agglomerates by absorbing water from the specimens. These agglomerates could reduce the cementation strength between the coarse coral particles and the cement. Meanwhile, the peak stress of CCS specimens was found to be negatively correlated with the average strain rate and the ultimate strain. The degree of specimen fracture was found to be correlated with the amount of specific energy absorption during the tests. Furthermore, the “sulfate attack” caused by the inclusion of salinity of water had different influences on the CCS specimens with different coral powder contents. The ettringite and gypsum produced in “sulfate attack” could fill the pores and lead to cracking of the specimens, significantly affecting the specimen strength.

珊瑚砂是珊瑚礁工程实践中的一种重要建筑材料。使用水泥作为稳定剂可显着改善珊瑚砂的力学性能，广泛应用于珊瑚礁岛底基层工程建设。 由于珊瑚砂的高破碎性和周围海水的存在，水泥稳定的珊瑚砂结构可能含有高含量的细珊瑚颗粒和盐度。在这项研究中，通过分裂霍普金森压力棒（SHPB）测试和扫描电子显微镜（SEM）分析，研究了珊瑚砂粉末和海水盐度对胶结珊瑚砂（CCS）动态力学性能的影响。发现随着粉末含量的增加，CCS试件的强度（即峰值应力）先增大后减小。当粉末含量为 3% 时，试样达到最大峰值应力。CCS 强度的初步提高归因于珊瑚粉的孔隙填充作用，即，实验中使用更高百分比的珊瑚粉可以更有效地填充 CCS 标本的微孔。然而，过多的珊瑚粉会导致试样强度降低，因为这些粉末很容易通过从试样中吸收水分而粘合成团块。这些附聚物会降低粗珊瑚颗粒与水泥之间的胶结强度。同时，发现CCS试样的峰值应力与平均应变率和极限应变呈负相关。发现试样断裂的程度与测试期间的比能量吸收量相关。此外，水的含盐量引起的“硫酸盐攻击”对不同珊瑚粉含量的CCS标本有不同的影响。