再生骨料及再生骨料混凝土的性能分析与评价

本文对国内外再生骨料和再生骨料混凝土的研究现状进行了分析,总结了再生骨料和再生骨料混凝土的基本性能.发现再生骨料的表观密度和堆积密度分别在231kg/m^3～2.62kg/m^3和1.29kg/m^3～1.47kg/m^3之间,其吸水率处于4%～10%之间,压碎指标在14.2%～23.1%之间.再生骨料混凝土抗压强度随再生骨料替代率增加而降低,随水灰比增大而降低.再生骨料混凝土的抗拉强度受替代率影响比较小.随着再生骨料替代率的增大,再生骨料混凝土的坍落度急剧下降、弹性模量降低、收缩值显著增大、抗冻性基本不变、渗透性增大、碳化速度略有增加、抗硫酸盐侵蚀性略有降低.基于众多文献研究成果,经回归分析提出了再生骨料混凝土抗压强度和弹性模量计算公式,最后讨论了再生骨料混凝土的应用状况.

Analyses and evaluation of the behaviour of recycled aggregate and recycled concrete

The obtained results about the present research of the recycled aggregate and recycled concrete were analyzed and the basic behaviour was summarized in this article. It was found that apparent density and stacking density are between 2.31-2.62(kg/m3)and 1.29-1.47(kg/m3), water absorption is 4%-10%, crush index is 14.2%-23.1%. The compressive strength of recycled concrete reduces with the increase of recycled aggregate substituting ratio and water/cement ratio. Its tensile strength was less affected by substituting ratio. With the increase of recycled aggregate substituting ratio, the slump of recycled concrete rapidly reduce, its elastic model reduce, its shrinkage markedly increase, its frost resistance is less infected, its permeability increase, its carbonization speed slightly increase, its sulphate resistance slightly reduce. Based on the previous experiments from large amount of investigation, the calculation formulas of compressive strength and elasticity modulus were proposed. And the application of recycled concrete was discussed in the end.