高丹盈+张丽娟+芦静云+闫兆强

摘要：通过再生骨料混凝土配合比试验，研究再生粗骨料材料性质对再生骨料混凝土配合比设计中水灰比、单方用水量和砂率等参数的影响；通过对试验结果的统计分析，建立了考虑再生骨料取代率影响的水胶比计算公式，考虑再生骨料吸水率和取代率影响的再生混凝土单方用水量计算公式，以及考虑再生骨料空隙率、取代率和表观密度影响的再生混凝土砂率计算公式。结果表明：再生骨料取代率、空隙率和吸水率对再生骨料混凝土配合比设计参数的影响较大；所得公式形式简单，反映了再生粗骨料的特点，提高了再生骨料混凝土配合比设计的精度，为再生混凝土配合比设计提供依据和参考。

关键词：再生骨料混凝土；配合比；水灰比；单方用水量；砂率

中图分类号：TU528文献标志码：A

Research on Design Parameters of Mix Proportion for Recycled

Aggregate ConcreteGAO Danying， ZHANG Lijuan， LU Jingyun， YAN Zhaoqiang

（Research Center of New Style Building Material & Structure， Zhengzhou University，

Zhengzhou 450002， Henan， China）Abstract： The influences of properties of recycled coarse aggregate on the key parameters of mix proportion design for recycled aggregate concrete， including watercement ratio， unit water content and sand ratio， were discussed through the mixture proportion tests. The formulas for calculating the key parameters of mix proportion for recycled aggregate concrete were established through the statistical analysis of test results， which considered the influences of replacement ratio of recycled aggregates in the waterbinder ratio formula， water absorption and replacement ratio in the unit water content formula， and void fraction， apparent density and replacement ratio in the sand ratio formula. The results indicate that the replacement ratio， void fraction and water absorption of recycled aggregates have significantly effect on the mix proportion of recycled aggregate concrete. The obtained formulas have simple forms， and reflect the characteristics of recycled aggregate， enhance the mix proportion design accuracy， and can provide reference for mix proportion design of recycled concrete.

Key words： recycled aggregate concrete； mix proportion； watercement ratio； unit water content； sand ratio

0引言

据估算，到2020年中国将新增建筑面积3×1010 m2，由此产生的废弃混凝土等建筑垃圾约为134×108 t，若单纯堆存将占地2.33×109 m2[1]，中国建筑垃圾的再生利用任重道远。再生骨料混凝土（Recycled Aggregate Concrete，RAC）是指以破碎加工后的废弃混凝土为骨料的混凝土。利用废弃混凝土做骨料可节省石灰石资源61%，减少15%～20%的CO2排放量[2]，从根本上解决废弃混凝土的处理问题，还能节约天然骨料，具有显著的经济、社会和环境效益。由废弃混凝土破碎得到的再生骨料表面往往包裹一层水泥砂浆，棱角多，针状物材料所占比例大，且破碎过程中会使再生骨料产生大量的内部横向裂纹。……