摘要
粗骨料母材混凝土强度是影响再生混凝土强度的主要因素,但实际工程中使用的商品再生粗骨料的母材混凝土来源及强度未知。为用易测量参数为指标建立混合来源粗骨料再生混凝土抗压强度预测模型,本工作收集制备了五种不同来源的再生粗骨料和一种商品再生粗骨料,按照不同的比例混合制备再生混凝土并进行强度测量。通过分析母材混凝土原始强度与设计强度之比(η)和再生粗骨料表观密度(ρ)、吸水率(ω)的关系,将母材混凝土强度对再生混凝土强度的影响转化为ρ及ω对其的影响,建立了混合再生混凝土抗压强度预测公式。结果表明,混合再生混凝土破坏形式取决于所含低强度粗骨料的比例,当低强度骨料比例由低变高时,破坏从骨料破坏转换为骨料-砂浆界面破坏;将公式计算强度与试验中不同比例粗骨料混合的再生混凝土强度及商品粗骨料混合再生混凝土强度进行对比得出,建立的仅考虑单一因子ρ影响的公式的计算误差在10%以内,同时考虑ρ和ω双因子影响的公式的计算误差在6%以内。
The original concrete strength of recycled coarse aggregate is the main factor affecting the strength of recycled concrete. However, it is difficult to confirm the source and strength of original concrete of commercial recycled coarse aggregate used in actual engineering. In order to establish a compressive strength prediction model of concrete with recycled coarse aggregate from various sources using easily measured parameters, five types of recycled coarse aggregate from different sources and one type of commercial recycled coarse aggregate were collected and prepared. The recycled concrete samples with different coarse aggregate mixing ratios were prepared and their strength test were carried out. The relationships between apparent density ( ρ ), water absorption ( ω ) and the ratio of original concrete strength to design strength ( η ) were analyzed. Based on the analysis, the influence of original concrete strength on mixed recycled concrete strength can be converted to ρ and ω , and then the prediction formula of compressive strength of mixed recycled concrete was proposed. The results show that the failure forms of mixed recycled concrete depend on the proportion of coarse aggregate containing with low strength. When the proportion of low-strength recycled aggregate changes from low to high, the failure form is transformed from aggregate failure to aggregate-mortar interface failure. By comparing the calculated strength by the formula and the strength of commercial coarse aggregate mixed recycled concrete by the test, the calculation error of the formula considering only the influence of a single factor ρ is within 10%, and the calculation error of the formula considering the influence of ρ and ω factors is within 6%.
作者
许开成
王文鹏
张立卿
XU Kaicheng;WANG Wenpeng;ZHANG Liqing(State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure,East China Jiaotong University,Nanchang 330013,China;School of Civil Engineering and Architecture,East China Jiaotong University,Nanchang 330013,China)
出处
《材料导报》
北大核心
2025年第12期86-94,共9页
Materials Reports
基金
国家自然科学基金(51968021,52368031)
中国博士后科学基金(2022M713497)
江西省自然科学基金(20224BAB204067)
轨道交通基础设施性能监测与保障国家重点实验室资助(HJGZ2022201)。
关键词
不同来源
母材混凝土强度
混合粗骨料再生混凝土
抗压强度
预测模型
different sources
original concrete strength
recycled concrete mixed with coarse aggregate
compressive strength
prediction model
