Xie Bing, Yuan Jian, Jiang Cheng-Jin
Department of Civil and Environmental Engineering, Imperial College London, London, SW72AZ, United Kingdom.
Academy of Combat Support, Rocket Force University of Engineering, Xi'an, 710025, China.
Heliyon. 2024 Nov 12;10(22):e40323. doi: 10.1016/j.heliyon.2024.e40323. eCollection 2024 Nov 30.
In order to study the durability of molybdenum tailings concrete after a specific period of wet-dry cycle tests and exposure to high temperatures, this paper investigates the rule of change of the mechanical properties of molybdenum tailings concrete under the coupled influence of sulfate corrosion and high-temperature environmental conditions. A total of five C30 concrete prisms with molybdenum tailings content (0 %, 25 %, 50 %, 75 %, and 100 %) were considered in the tests, with sulfate solution concentrations of 0 g/L, 20 g/L, and 50 g/L, and exposure temperatures of 25° at room temperature and 400° at high temperature, respectively. The test results showed that the mass loss rate of concrete prisms with different molybdenum tailings substitution rates under sulfate corrosion and high temperature environment showed an increasing and then decreasing trend. The specimens with 25 % molybdenum tailings content still maintain high mechanical properties after wet-dry cycle tests of sulfate solution and high temperature, and the reduction of peak stress in this group is only 11 %, and the reduction of elastic modulus is 1 %; the rest of the molybdenum tailings content has a reduction of peak stress of about 25 %, and the reduction of modulus of elasticity is more than 10 %. The plastic deformation capacity of molybdenum tailings concrete decreases under the single-factor effects of wet-dry cycle tests of sulfate solution and high temperature effects, but the plastic deformability capacity of the specimens is enhanced under the combined effects of multiple factors. The stress-strain curve formulas for molybdenum tailings concrete under high temperature, wet-dry cycle tests of sulfate solution, and coupled wet-dry cycle tests of sulfate solution and high temperature were fitted. The results of this study can provide experimental data and valuable references for the engineering application of molybdenum tailings concrete under wet-dry cycle tests of sulfate solution and high temperature conditions, laying a foundation for further research.
为研究钼尾矿混凝土在经历特定干湿循环试验和高温作用后的耐久性，本文研究了在硫酸盐侵蚀与高温环境耦合作用下钼尾矿混凝土力学性能的变化规律。试验共考虑了5个不同钼尾矿掺量（0%、25%、50%、75%和100%）的C30混凝土棱柱体，硫酸盐溶液浓度分别为0 g/L、20 g/L和50 g/L，暴露温度分别为室温25℃和高温400℃。试验结果表明，在硫酸盐侵蚀和高温环境下，不同钼尾矿替代率的混凝土棱柱体质量损失率呈先增加后降低的趋势。钼尾矿掺量为25%的试件在经历硫酸盐溶液干湿循环试验和高温作用后仍保持较高力学性能，该组试件峰值应力降低仅11%，弹性模量降低1%；其余钼尾矿掺量的试件峰值应力降低约25%，弹性模量降低超过10%。在硫酸盐溶液干湿循环试验和高温单因素作用下，钼尾矿混凝土的塑性变形能力降低，但在多因素耦合作用下试件的塑性变形能力增强。拟合得到了高温、硫酸盐溶液干湿循环试验以及硫酸盐溶液与高温耦合干湿循环试验作用下钼尾矿混凝土的应力-应变曲线公式。本研究结果可为钼尾矿混凝土在硫酸盐溶液干湿循环试验和高温条件下的工程应用提供试验数据和有价值的参考，为进一步研究奠定基础。
