Abstract: Red sandstone is widely distributed in China, and its disintegration is very significant due to changes in water content. The red sandstone samples from Zhuzhou area of Hunan Province were used to conduct laboratory static and disturbed disintegration tests. Then, an evolution model of gradation curve of particle disintegration of red sandstone was established based on the Weibull distribution, and the model parameters λ and k were analyzed, the value and change rate of the two parameters reflect the evolutionary process of particle disintegration and breakage of red sandstone. Moreover, on the basis of established model, the calculation formula of the relative disintegration ratio was obtained, and the correctness of the formula was verified. Furthermore, according to the test results and the values of model calculation, the similarities and differences between the slaking durability index and the disintegration ratio, and the effects of different test methods on the test results were discussed. Finally, the feasibility of application of Weibull distribution model to the evolution of rock particle disintegration is verified based on the existing researches.

Key words: red sandstone, disintegration, breakage, Weibull distribution, drying and wetting cycle