Effect of freezing temperature on Brazilian splitting characteristics of frozen soil-rock mixture with different particle sizes

Abstract

In order to study the Brazilian splitting characteristics of the frozen stone mixture under the coupling effect of freezing temperature and size effect, Brazilian splitting experiments were conducted on 5-10, 10-15, 15-20, and 5-20 mm particle size frozen soil-rock mixture samples after freezing at −10, −15, −20, −25, −30, −35, and −40 ℃ to investigate the effects of freezing temperature and different particle sizes on the splitting tensile strength of the samples. The effects of freezing temperature and different particle sizes on the splitting tensile strength of the samples were investigated, and the strain field evolution of the frozen soil-rock mixture during the Brazilian splitting experiments was further reproduced by digital imagine correlation (DIC). The experimental results show that the tensile strain is concentrated in the sample center with initial crack produced and the splitting damage pattern of the samples is curved and folded, and the larger the particle size is, the more curved the crack is; frozen soil-rock mixture goes through the linear elastic deformation stage when it breaks, and goes through the plastic-brittle damage stage with the increase of tensile stress and the decrease of freezing temperature; the splitting tensile strength has strong temperature sensitivity and increases approximately linearly with the decrease of freezing temperature; the size effect leads to the variability of sample strength, and the splitting tensile strengths are in the order of 5-10, 5-20, 10-15, and 15-20 mm particle size samples.

Keywords

• frozen soil-rock mixture
• particle size
• splitting tensile strength
• damage pattern
• digital image correlation technique