Investigation of Pore Characteristics in Coral Sand Particles

The pore structure of coral sand is closely related to the breakage characteristics and strength of coral sand particles. Investigating the pore structure of coral sand is helpful to explore the mechanical and deformation characteristics of coral sand. However, the research on the internal pores of coral sand particles is still insufficient and further research is needed. In this paper, the nitrogen gas adsorption method and fractal theory are used to determine the internal pore characteristics and the surface fractal dimension D of coral sand particles. The test results showed that the isotherm adsorption and desorption curve of coral sand is an IV type curve with a H3 type hysteresis loop. The pores on the sand surface are relatively developed, the pore shape is long and narrow, and the average specific surface area is 1.217 m2/g. The width of mesoporous pores is distributed in the range of 2–37 nm, but the pore width is mainly distributed between 5 and 35 nm, and most of the pore volume is less than 0.001 cm3/g. The calculation result of fractal dimension showed that the surface of coral sand is relatively rough, and the average fractal dimension D = 2.39. The above research results can be used as a reference for the study of the mechanical properties of coral sand.