Mechanical Properties and Crushing Mechanism of Reef Coral–Sand Mixture

Abstract

Wang, W.; Li, W.; Yao, Z.; Zhang, Z., and Zhou, L., 2020. Mechanical properties and crushing mechanism of reef coral–sand mixture. In: Yang, D.F. and Wang, H. (eds.), Recent Advances in Marine Geology and Environmental Oceanography. Journal of Coastal Research, Special Issue No. 108, pp. 16–21. Coconut Creek (Florida), ISSN 0749-0208.The coral sand used in engineering is often mixed with silica particles and other impurities to form a coral-sand mixture. To explore the mechanical properties of this mixture and the crushing mechanism of the particles, standard sand particles of diameters 0.3–0.5 mm and 0.5–0.85 mm replaced the corresponding sizes of coral sand with equal mass. Under the same relative compactness condition, the water content and vertical load were set, and direct shear tests were performed. The results show that the incorporation of standard sand reduces the shear strength of coral sand, and the effect is most apparent when the 0.3–0.5 mm particles are replaced. As the water content increases, the cohesion of the coral sand mixture decreases, whereas the internal friction angle first increases and then decreases. The particle breakage of coral sand increases as the vertical load increases and decreases as the water content increases. Therefore, replacement of standard sand can reduce the particle breakage rate of coral sand.