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Metal Mine ›› 2020, Vol. 49 ›› Issue (11): 1-10.

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Study on the Influence of Water-cement Ratio on the Physico-mechanical Properties of Rock-like Materials under Freeze-thaw

LIU Yanzhang,WANG Jin,HUANG Shibing,LU Zexin,LIU Yatian,GUO Yunlin   

  1. 1. College of Resource and Environmental Engineering,Wuhan University of Science and Technology,Wuhan 430081,China;2. Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources,Wuhan 430081,China
  • Online:2020-11-15 Published:2020-12-22

Abstract: The rock mass of the mine slope in the alpine region will experience the freeze-thaw cycle, causing damage and weakening of the rock mass structure, which will pose a hazard to the stability of the mine slope. Cement mortar is a commonly used rock-like material to simulate fractured rock mass, and its mixing ratio has great influence on the frost resistance of this kind of rock material. In order to investigate the influence of water cement ratio on the physical and mechanical properties of rock-like materials under freeze-thaw, rock-like standard specimens with seven different water cement ratios were prepared. Freeze-thaw cycles and uniaxial compression tests after 0~50 cycles were carried out. The results show that: ① In the absence of freezing-thawing, increasing water cement ratio, the porosities and densities of the specimens increase while the P-wave velocities decrease. During freezing-thawing, the P-wave velocity decreases with the increase of freezing-thawing cycles, and it reduces faster as the water cement ratio increase. ② With the increase of water-cement ratio,the uniaxial compressive strength and elastic modulus of rock-like materials increase firstly and then decrease. When water cement ratio is 0.325~0.35, the uniaxial compressive strength of rock-like materials is the highest and the frost resistance is the best. ③ With the increase of freeze-thaw cycles, the stress-strain curves of these specimens tend to be flat, which illustrates they transform from brittleness to ductility. Besides, a larger deformation of the pore compaction stage arises for higher water cement ratio. The study results can provide a reference in the proportion design of freeze-thaw damage experiment of mine slope and related rock mass engineering.

Key words: rock-like materials, water cement ratio(w/c), freeze-thaw cycle, uniaxial compressive strength, modulus of elasticity