侵蚀损伤与高温耦合作用下改性煤矸石混凝土的损伤劣化规律

The law of damage and deterioration of modified coal gangue concrete under the coupling action of erosion damage and high temperature

分别研究冻融侵蚀损伤及硫酸盐侵蚀损伤的改性煤矸石混凝土在200、400、600、800℃高温前后的损伤劣化规律,并从质量损失率、劈裂抗拉强度损失率及抗压强度损失率方面进行探讨分析。结果表明:钢纤维和矿物掺合料的加入显著提高了煤矸石混凝土在侵蚀损伤-高温耦合作用后的力学性能,其中粉煤灰-矿粉-钢纤维三者复合作用效果最优。建立了以抗压强度损失率为损伤变量的侵蚀损伤-高温耦合劣化模型,可以较好地表征冻融侵蚀-高温耦合及硫酸盐侵蚀-高温耦合下的改性煤矸石混凝土的损伤劣化规律。

The damage and deterioration laws of modified coal gangue concrete damaged by freeze-thaw erosion and sulfate erosion before and after 200,400,600 and 800℃were studied respectively,and the mass loss rate,splitting tensile strength loss rate and compressive strength loss rate were discussed and analyzed.The results show that the addition of steel fiber and mineral admixture can significantly improve the mechanical properties of coal gangue concrete under the coupling action of erosion damage and high temperature,and the composite effect of fly ash,mineral powder and steel fiber is the best.The erosion damage-high temperature coupled deterioration model with compressive strength loss rate as damage variable was established.The model can better characterize the damage and deterioration law of modified coal gangue concrete under freeze-thaw erosion-high temperature coupling and sulfate erosion-high temperature coupling.