冷却方式对高温后再生混凝土力学性能的影响

发布时间：2018-05-13 05:37

本文选题：再生混凝土 + 冷却方式　；参考：《建筑材料学报》2017年05期

【摘要】：为了研究冷却方式对高温后再生混凝土力学性能的影响,以再生粗骨料取代率、受热温度、冷却方式为参数,设计了111块再生混凝土立方体标准试块,进行高温后力学性能试验,考察了不同冷却方式下试块的表观变化、破坏形态以及性能指标,分析其残余强度影响规律,并给出了相应强度计算方法.结果表明:随着受热温度的升高,试块表面颜色变浅、裂缝增多、破损程度加重;质量烧失率增大,且其增大趋势在自然冷却条件下先快后慢,在喷水冷却条件下倾向于线性变化;试块残余强度随着温度的升高而逐渐降低,与自然冷却相比,喷水冷却后的残余强度呈现先高后低、再高再低的变化趋势;在试验基础上提出的不同冷却方式下残余强度计算公式计算结果与已有试验数据吻合良好.
[Abstract]:In order to study the effect of cooling method on mechanical properties of recycled concrete after high temperature, 111 recycled concrete cubic standard test blocks were designed with the parameters of recycled coarse aggregate replacement rate, heating temperature and cooling mode. The mechanical properties after high temperature were tested, and the apparent changes, failure patterns and performance indexes of the test blocks under different cooling methods were investigated. The influence law of the residual strength was analyzed, and the corresponding strength calculation method was given. The results show that with the increase of heating temperature, the surface color of the specimen becomes lighter, the cracks increase, the degree of damage increases, the mass loss rate increases, and the increasing trend of mass loss increases at first and then slowly under the natural cooling condition. The residual strength of the sample decreases gradually with the increase of temperature. Compared with the natural cooling, the residual strength of the spray cooling tends to be higher then lower, then higher and lower. The calculated results of the formula for calculating residual strength under different cooling methods are in good agreement with the existing experimental data.
【作者单位】：广西大学土木建筑工程学院;广西大学工程防灾与结构安全教育部重点实验室;广西大学广西防灾减灾与工程安全重点实验室;
【基金】：国家自然科学基金资助项目(51508112,51668007,51468003) 广西自然科学基金资助项目(2015GXNSFBA139210) 广西教育厅中青年教师基础能力提升项目(KY2016YB027,KY2016YB666) 广西重点实验室系统性研究项目(2016ZDX02)
【分类号】：TU528

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