高性能再生骨料混凝土试验研究

Experimental Study on High Performance Recycled Aggregate Concrete

目的采用再生骨料配制高性能再生骨料混凝土,研究其单轴受压应力-应变行为,为再生骨料混凝土结构的数值分析提供理论基础.方法通过改变再生骨料的取代量,研究再生骨料对高性能再生骨料混凝土的强度、渗透性、抗冻耐久性及单轴受压应力-应变行为的影响.结果试验配制的高性能再生骨料混凝土28 d抗压强度超过70 MPa,抗冻等级达F300,得出单轴受压应力-应变曲线,并对其进行数值模拟,两者吻合较好.结论采用再生骨料能够配制出高性能再生骨料混凝土,其单轴受压应力-应变曲线与普通混凝土具有相似的规律,随着再生骨料取代量的增加,高性能再生骨料混凝土延展性得到提高,且数值拟合单轴受压应力-应变曲线相关性高,可用于分析混凝土的本构关系.

In this testing research, we prepared a series of High Performance Recycled Aggregate Concrete （HPRAC） with recycled aggregate and tested their uniaxial compressive stress-strain behavior, which will provide theoretical foundation for numerical analysis of Recycled Aggregate Concrete （RAC） structure. We studied the influence of the replacement of recycled aggregate on the strength, permeability, frost resistance and uniaxial compressive stress-strain behavior of HPRAC by changing replacement ratio of recycled aggregate. Testing results show that the compressive strength of HPRAC is higher than 70MPa at 28d and their frost resistance gradation reached F300, and the fitted regression curve approaches measured curve. In brief, we can prepare HPRAC with recycled aggregate. The uniaxial compressive stress-strain curve is similar to that of ordinary concrete and the ductibility of HPRAC is improved with the increase of the content of recycled aggregate. There is high relativity between the fitted regression curve and measured curve, and that can be used in constitutive relations analysis for Concrete.