Crack Propagation and Material Characteristics of Rocklike Specimens Subject to Different Loading Rates

Abstract

This paper evaluates the cracking mechanism and material characteristics of rocklike specimens under five loading rates (0.02, 0.06, 0.10, 0.14, and 0.18 mm/s). The rocklike cylinder specimens were prepared and mixed using river sand (as aggregate sources) and cement, gypsum, and starch (as binders). Uniaxial compression tests associate with binarization imaging processing were carried out using the five loading rates to evaluate the cracking propagations and characteristics of rocklike specimens. The results show that with the increase in the loading rate, the peak tensile and compressive strengths of the rocklike specimen increases. The relationship between the ratio of stress to peak stress, and the five loading rates of the rocklike specimen can be expressed as a natural logarithm model while the relationship between the initial crack length of the rocklike specimen and the five loading rates can be represented by as an exponential function. The average rate of crack propagations increases exponentially as the loading rate increases. Based on all test and analysis results and, the paper concludes that the characteristics of cracking mechanism, propagations, and characteristics of rocklike materials show the similar mechanical behaviors as compared with other rock specimens.