再生混凝土弹性模量变化规律试验研究

Experimental Study on the Variation Law of Elastic Modulus of Recycled Aggregate Concrete

结合不同工程领域对混凝土结构弹性模量高低的要求有所不同的实际情况,针对C20、C30、C40等中低强度等级再生混凝土,进行了不同再生粗骨料取代率情况下的弹性模量变化规律试验研究。试验结果分析表明:再生混凝土中骨料、水泥浆基体、过渡区等因素对混凝土结构的影响与普通基准混凝土存在差异,导致在同强度等级的再生混凝土中,其弹性模量随着再生粗骨料取代率的增加而呈明显下降的趋势。试验所建立的再生混凝土的弹性模量ER与基准混凝土弹性模量E0、再生粗骨料取代率R之间的相关关系式ER=E0(1+0.127 8R-1.802 3R2+2.458 5R3-1.05R4),可以在实际工程中结合对再生混凝土弹性模量的不同要求,为再生粗骨料的合理取代率做出估计。

For meeting the different requirements of actual conditions in the various engineering field,the paper study the variation law of the elastic modulus of various strength recycled aggregate concrete from C20 to C40 with the different replacement rate of recycled coarse aggregate.Experimental results show that some factors such as aggregate,cement matrix,interfacial transition zone and so on have different influence on concrete structure between recycled aggregate concrete and base concrete.Moreover,these factors lead to the elastic modulus of the same strength recycled aggregate concrete is obviously decreased with the increasing of the replacement rate of recycled coarse aggregate.According to the experimental data and theoretical analyses,the relational expression is obtained between the elastic modulus of recycled aggregate concrete,the elastic modulus of base concrete and the replacement rate of recycled coarse aggregate.Combined with the different requirements of elastic modulus of recycled aggregate concrete of the actual projects,it can make an estimate of the replacement rate of recycled coarse aggregate.