College of Civil Engineering, Taiyuan University of Technology
Saint Petersburg State University

【目的】内部多孔且高温稳定的玻化微珠(glazedhollowbeads,GHB)可在一定程度上减缓混凝土的高温损伤劣化,提升混凝土的抗火性能。为了进一步明确GHB改善混凝土抗火性能的机理,从细观尺度出发,提出一种可考虑初始缺陷和再生骨料(recycledcoarseaggregate,RCA)取代率的再生保温混凝土(recycledaggregateconcretemixedwithglazedhollowbeads,RATIC)细观模型的建模方法。【方法】利用现阶段比较常用的塑性损伤模型,探究了RCA取代率(0,50%,100%)、GHB含量(0,70%,100%)和孔隙率(0,2%,4%)对于高温后RATIC力学性能的影响。【结果】结果表明:随着受火温度的提高,荷载作用下RATIC试件的损伤分布均呈现出逐渐加剧的趋势,且500℃后,试件的损伤分布较400℃之前严重。GHB的加入可在一定程度上缓减混凝土内部的损伤劣化,而RCA的加入会加剧此现象。此外,随着孔隙率增大,RATIC试件的强度逐渐变低。

【Purposes】 The internally porous and highly thermally stable glazed hollow beads (GHB) can reduce the high temperature damage and deterioration of concrete to a certain extent, and improve the fire resistance of concrete. In order to further clarify the mechanism of GHB in improving the fire resistance of concrete, starting from the meso-scale concrete, we proposed a modeling method for RATIC meso-scale model that can take into account the initial defects and the replacement rate of recycled coarse aggregate (RCA). 【Methods】 The effects of RCA replace- ment rates (0, 50%, 100%), GHB contents (0, 70%, 100%), and porosity (0, 2%, 4%) on the mechanical properties of RATIC after high temperature were explored by utilizing the plastic damage model commonly used at curent stage. 【Findings】 The results show that with the in- crease of fire temperature, the damage distributions of the RATIC specimens under load exhibit a gradually increasing trend, and the damage distribution of the specimens after ℃ is more se- rious than that before ℃. The addition of GHB alleviates the damage and deterioration inside the concrete to a certain extent, while the addition of RCA exacerbates this phenomenon. In addi- tion, the strength of RATIC specimens gradually decreases with the increase of porosity.

国家自然科学基金国际合作与交流项目(5201101735);RussianFoundationforBasicResearch(21-51-53008)

刘淑钰,苗艳春,李明厚,等.高温后再生保温混凝土损伤劣化数值分析[J].太原理工大学学报,2024,55(5):892-904.

LIU Shuyu,MIAO Yanchun,LI Minghou,et al.Numerical analysis of damage and deterioration of recycled ag-gregate concrete mixed with glazed hollow beads after high temperature[J].Journal of Taiyuan University of Technology,2024,55(5):892-904.