烧结砖粗骨料取代率对再生混凝土柱轴压性能的影响

Experimental investigation on axial compression performance of recycled clay brick aggregate concrete columns

研究烧结砖再生粗骨料取代率对再生混凝土抗压强度和再生混凝土柱轴压性能的影响.以烧结砖再生粗骨料取代率为变量,设计并完成15个标准立方体试块和15个棱柱体试块的抗压试验,10根取代率分别为0%、25%、50%、75%和100%的再生混凝土柱进行轴心受压试验.结果表明:随着取代率的增加,再生混凝土的立方体抗压强度、棱柱体抗压强度和柱极限承载力呈下降趋势,柱极限承载力时的裂缝最大宽度和柱端轴向相对位移呈上升趋势;采用现行规范计算柱极限承载力时,试验值比计算值略小,可对混凝土强度进行系数折减,折减系数与取代率有关.

In order to study the effects of the replacement ratio of clay brick recycled coarse aggregate(CBRCA)on the mechanical properties of recycled concrete and recycled reinforced concrete columns under axial compression,the measured strength tests of 15 cube and 15 prism CBRCA concrete as well as the axial compression tests of 10 concrete columns incorporating 0%,25%,50%,75%,and 100%level of CBRCA,were conducted.The experimental results show that higher replacement ratio of CBRCA will lead to smaller cubic and prismatic compressive strength and lower axial compression bearing capacity of the columns.Meanwhile,when the columns are loaded to their bearing capacity,higher CBRCA level tends to result in wider crack and larger axial relative displacement at the end of the column.Besides,the axial compression bearing capacity measured by experiments is slightly smaller than the one calculated by current standard relevant formula,and the coefficient reduction of the concrete strength can be carried out according to the formula proposed in this paper.