再生骨料混凝土配合比设计参数研究

Research on Design Parameters of Mix Proportion for Recycled Aggregate Concrete

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。

The influences of properties of recycled coarse aggregate on the key parameters of mix proportion design for recycled aggregate concrete,including water-cement 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 water-binder 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 significant 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.