NaOH浓度对地聚物再生骨料混凝土尺寸效应的影响  

Influence of NaOH concentration on size effect of geopolymer recycled aggregate concrete

作　　者：周静海[1] 苏群 丁兆洋 ZHOU Jinghai;SU Qun;DING Zhaoyang(School of Civil Engineering,Shenyang Jianzhu University,Shenyang 110168,China)

机构地区：[1]沈阳建筑大学土木工程学院,辽宁沈阳110168

出　　处：《混凝土》2024年第9期1-5,共5页Concrete

基　　金：国家自然科学基金面上项目(51678374);住房和城乡建设部科技计划项目(2019-K-48);硅酸盐建筑材料国家重点实验室(武汉理工大学)开放基金(SYSJJ2020-15)。

摘　　要：设计了4种不同立方体尺寸(70 mm、100 mm、150 mm和200 mm)和5种不同NaOH浓度(3 mol/L、5 mol/L、7 mol/L、9 mol/L、11 mol/L)的地聚物再生骨料混凝土试块,研究了不同NaOH浓度条件下的地聚物再生骨料混凝土抗压强度的尺寸效应。通过试验发现:GB/T 50081-2002《普通混凝土力学性能试验方法标准》中规定的换算系数并不适用于地聚物再生骨料混凝土,给出2种方法来进行地聚物再生骨料混凝土尺寸换算系数的取值,第一种是平均数方法:α_(200)=0.93、α_(100)=1.13、α_(70)=0.70,第二种方法采用线性拟合:α_(200)=0.9735-0.0065ε、α_(100)=1.0445+0.0125ε、α_(70)=0.718-0.002ε;尺寸为200 mm、150 mm和100 mm的地聚物再生骨料混凝土抗压强度均符合Bazant的尺寸效应理论曲线,采用无量纲的方法可以得到地聚物再生骨料混凝土抗压强度与NaOH浓度和尺寸参数耦合作用影响的预测方程,所提出的方程具有更好的适用性,并且得出了不同NaOH浓度条件下地聚物再生骨料混凝土的临界尺寸和临界强度值。The effect ofNaOH concentration(3 mol/L,5 mol/L,7 mol/L,9 mol/L,and 11 mol/L)on the size effect of geopolymer recycled aggregate concrete was studied by 4 different size specimens(70 mm,100 mm,150 mm and 200 mm).The results show that the conversion coefficient of geopolymer recycled aggregate concrete cannot be used as specified in GB/T 50081-2002 Standard for Testing Methods for Mechanical Properties of Ordinary Concrete.Two methods were used to evaluate the size conversion coefficient of regenerated aggregate concrete.The first method was the mean method:α_(200)=0.93,α_(100)=1.13,α_(70)=0.70.The second method was linear fitting:α_(200)=0.9735-0.0065ε,α_(100)=1.0445+0.0125ε,α_(70)=0.718-0.002ε.The compressive strength of recycled aggregate concrete of 200 mm,150 mm and 100 mm are in line with the Bazant's theory of size effect curve,adopt the method of dimensionless can get polymer compressive strength of recycled aggregate concrete and NaOH concentration and size parameters of the prediction equation of coupling effect,the applicabilty of the proposed equation has better,and it is concluded that the different conditions of recycled aggregate beneath gathered the strength of recycled aggregate concrete critical size and critical value.

关 键 词：地聚物再生骨料混凝土 抗压强度 尺寸效应 NaOH浓度 

分 类 号：TU528.01[建筑科学—建筑技术科学]