碱激发矿渣-粉煤灰基再生混凝土抗压强度尺寸效应研究  

Size Effect on Compressive Strength of Alkali-activated Slag/Fly Ash-based Concrete

作　　者：万方雄 蒋国龙 吴峰 李彪 WAN Fangxiong;JIANG Guolong;WU Feng;LI Biao(Wuhan Qingshan North Lake Construction and Installation Engineering Co.,Ltd.,Wuhan,Hubei 420107,China;School of Civil Engineering,Architecture and Environment,Hubei University of Technology,Wuhan,Hubei 430068,China)

机构地区：[1]武汉市青山北湖建筑安装工程有限公司,湖北武汉420107 [2]湖北工业大学土木建筑与环境学院,湖北武汉430068

出　　处：《水利与建筑工程学报》2024年第3期182-188,220,共8页Journal of Water Resources and Architectural Engineering

基　　金：国家自然科学基金项目(202308248);湖北省自然科学基金项目(2023AFB309)。

摘　　要：为研究矿渣-粉煤灰基碱激发再生混凝土(AARAC)的尺寸效应,制备72个不同试件尺寸(70.7 mm、100 mm、150 mm和200 mm)的立方体试块,进行抗压强度试验,分析再生骨料取代率对AARAC抗压强度及其尺寸效应的影响规律。基于Bazant′s尺寸效应律,建立AARAC抗压强度尺寸效应计算方法。在此基础上,提出AARAC的抗压强度尺寸效应转换系数以及临界尺寸与临界强度。结果表明:随着再生骨料取代率增大,AARAC抗压强度不断下降,其降低幅度约为4.0%~30.4%,但其尺寸效应更加显著;规范GB/T 50081—2019中普通混凝土抗压强度尺寸效应换算系数并不完全适用于AARAC。提出的尺寸转换系数及临界尺寸与临界强度能较好预测不同试件尺寸条件下AARAC的抗压强度。In order to analyze the size effect of alkali-activated recycled aggregate concrete(AARAC),a total of 72 AARAC cubes with four specimen sizes of 70.7 mm,100 mm,150 mm and 200 mm were tested to obtain the compressive strength.The effect of recycled aggregate(RA)substitute rate on the compressive strength and its size effect was analyzed.The results show that the compressive strength of AARAC decreases with increasing RA substitute rates due to the increased amount of defects,with the decreasing amplitudes of about 4.0%~30.4%,except that their size effect becomes more apparent.Based on Bazant′s size effect law(SEL),analytical model for SEL of compressive strength of AARAC was established,and the critical size and critical strength of AARAC were further proposed.Finally,conversion factors were suggested for the transformation of the compressive strength measurements of AARAC.

关 键 词：碱激发混凝土 再生骨料取代率 抗压强度 尺寸效应 尺寸效应率 

分 类 号：TU528[建筑科学—建筑技术科学]