Analysis of the dynamic mechanical properties of marble after high-temperature exposure based on microscopic mechanisms
To study the effect of temperature on the dynamic mechanical properties of marble,dynamic compres-sion tests,XRD,and SEM microscopic tests were conducted on marble samples at room temperature(25℃)and after exposure to high temperatures(200℃,400℃,600℃,and 800℃).The relationship between the dynamic mechani-cal properties of marble and temperature,as well as the microscopic damage mechanisms,were explored.The results show that the dynamic compressive stress-strain curves of marble after high-temperature exposure can be divided into 3 stages:elastic,yield,and failure.The peak stress and failure characteristics of marble exhibit a significant tempera-ture effect:as the temperature increases,the peak stress of marble gradually decreases,and the degree of fragmentation intensifies.The dynamic mechanical properties of marble are closely related to its mineral composition and crystal structure.Between 200℃and 600℃,micro-defects increase,and dolomite undergoes thermal decomposition and transformation.At 800℃,mineral decomposition produces CO2 gas and calcium hydroxide,and the crystal structure undergoes melting damage,leading to severe internal damage and increased plasticity,resulting in a substantial decline in macroscopic mechanical properties.
deep miningmarblehigh-temperature effectmicroscopic damage mechanismdynamic mechanical propertydynamic compression test
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