人民长江2024，Vol.55Issue(5)：186-195,10.DOI:10.16232/j.cnki.1001-4179.2024.05.025
高温下掺再生骨料及纤维混凝土物理力学性能研究
Experimental study on physical and mechanical properties of ultra-high performance concrete with recycled coarse aggregate and steel fiber under high temperature
摘要
Abstract
At present,the research on the performance of concrete with recycled coarse aggregate and fiber is relatively suffi-cient,but the understanding on its performance changes after high temperature treatment is insufficient.To this end,three types of concrete,namely ultra-high performance concrete(UHPC),50%recycled coarse aggregate UHPC(50%R-UHPC),and 50%recycled coarse aggregate-1.0%steel fiber UHPC(50R-1.0%S-UHPC),were treated under high temperature(200℃,400℃,600℃,800℃).Then the mechanical properties of the concretes,including uniaxial compressive strength,elastic modulus,splitting tensile strength,and flexural strength,as well as impermeability and thermal conductivity were studied.The results indi-cate that the addition of recycled coarse aggregate to the concrete weakens its mechanical properties,impermeability,and thermal conductivity,resulting in a decline in compressive,tensile,and flexural strength,as well as an increase in porosity and permeabili-ty.However,the addition of steel fibers enhances the mechanical properties and thermal conductivity of the concrete,but also re-sults in an increase in porosity and permeability.High temperature treatment weakens the concrete mechanical properties,imper-meability,and thermal conductivity,and there is a threshold temperature of 400℃.Prior to 400℃,the impact of high temperature treatment on these properties is minimal,but once the threshold is exceeded,the properties weaken rapidly.With respect to both UHPC and 50%R-UHPC,the differences in mechanical properties and thermal conductivity gradually diminish with the increase of the treatment temperature.关键词
超高性能混凝土/再生骨料/钢纤维/高温处理/力学性能/抗渗性能/导热性能/经验预测模型Key words
ultra-high performance concrete/recycled aggregate concrete/steel fiber/high temperature treatment/mechan-ics properties/impermeability/thermal conductivity/empirical prediction model分类
建筑与水利引用本文复制引用
刘新伟,任皎龙..高温下掺再生骨料及纤维混凝土物理力学性能研究[J].人民长江,2024,55(5):186-195,10.基金项目
国家自然科学基金项目(51808326) （51808326）
