再生粗骨料品质和掺量对再生混凝土力学性能的影响

Effect of Recycled Coarse Aggregate Quality and Content on Mechanical Properties of Recycled Concrete

采用两种再生粗骨料(RAⅠ、RAⅡ)分别替代30%、50%、70%、100%的天然粗骨料,以及将两种再生粗骨料以不同质量比(m_(RAⅠ)∶m_(RAⅡ)=1∶3、1∶1、3∶1)混合后替代30%、50%、70%、100%的天然粗骨料制备了再生混凝土,研究了不同再生粗骨料的品质和掺量对再生混凝土抗压强度、劈裂抗拉强度和轴心抗压强度的影响。结果表明:再生混凝土的抗压强度、劈裂抗拉强度和轴心抗压强度均随着再生粗骨料掺量的增加而降低;当再生粗骨料掺量一定时,再生混凝土的力学强度随着m_(RAⅠ)∶m_(RAⅡ)的增大而增大;参考GB 50010—2010《混凝土结构设计规范》建立的再生混凝土轴心抗压强度与立方体抗压强度关系式的拟合效果较好。

Recycled concrete was prepared by using two kinds of recycled coarse aggregate(RAⅠ,RAⅡ)to replace 0,30%,50%,70%and 100%natural coarse aggregate respectively,and using mixed recycled coarse aggregate(m_(RAⅠ)∶m_(RAⅡ)=1∶3,1∶1,3∶1)to replace 0,30%,50%,70%and 100%natural coarse aggregate.The effects of different quality and content of recycled coarse aggregate on the compressive strength,splitting tensile strength and axial compressive strength of recycled concrete were studied.The results show that the compressive strength,splitting tensile strength and axial compressive strength of recycled concrete decrease with the increase of recycled coarse aggregate content.When the content of recycled coarse aggregate is constant,the mechanical properties of recycled concrete increase with the increase of m_(RAⅠ)∶m_(RAⅡ).The relationship between the axial compressive strength and the cubic compressive strength of recycled concrete established by referring to GB 50010—2010 Code for Design of Concrete Structures has a good fitting effect.