摘要
为研究替代率对再生混凝土抗压强度影响的微观机理,本文对6种不同替代率的再生混凝土进行抗压试验、骨料分布试验,探究了其抗压强度随替代率变化的基本规律,同时利用Fourier变换红外光谱(FTIR)、电镜(SEM)和压汞法(MIP)分析该变化规律的微观机理。结果表明,随着替代率的增加,再生混凝土抗压强度呈现逐渐下降的规律。再生混凝土水化产物C-S-H凝胶和Ca(OH)2逐渐减少,阻碍了其水化发展。再生混凝土内部孔洞数量及有害孔累计孔体积百分比增大,且孔隙率升高,进而导致其抗压强度降低。基于试验结果建立了适用此类再生混凝土在不同替代率下抗压强度的计算公式。
In order to study the microcosmic mechanism for the influence of substitution rate on the compressive strength of recycled concrete,this paper carries out compressive tests and aggregate distribution tests on six recycled concrete at different substitution rates,and explores the basic law of the change of its compressive strength at the substitution rate.At the same time,the microcosmic mechanism for the change law is analyzed by the Fourier transform infrared spectroscopy(FTIR),the electron microscopy(SEM)and the mercury intrusion method(MIP).The results show that the compressive strength of recycled concrete decreases gradually with the increase of replacement rate.The hydration products of recycled concrete,C-S-H gel and Ca(OH)2,decreased gradually,hindering its hydration development.The number of holes in recycled concrete and the cumulative percentage of harmful holes increase,and the porosity increases,leading to the decrease of its compressive strength.Based on the test results,a formula for calculating the compressive strength of this kind of recycled concrete at different replacement rates is established.
作者
魏康
李犇
孙峤
WEI Kang;LI Ben;SUN Qiao(College of Civil Engineering and Architecture,Dalian University,Dalian 116622,China;School of Transportation and Civil Architecture,Foshan University,Foshan 528000,China)
出处
《西安理工大学学报》
CAS
北大核心
2023年第1期110-117,共8页
Journal of Xi'an University of Technology
基金
广东省教育厅高校科研资助项目(2021KQNCX083)
广东省科技研发专项资助项目(GDKTP2020032800)
大连大学大学生创新创业训练计划资助项目(202111258422)。
关键词
再生混凝土
抗压强度
微观机理
孔结构
水化产物
recycled concrete
compressive strength
microscopic mechanism
pore structure
hydration products
