【摘要】 为研究人工砂再生混凝土的剪切性能,制作36根具有不同强度等级(C35、C45)、不同人工砂取代率(0%、30%、50%、70%、100%)的四点受力等高变宽梁,通过连续加载方式进行试验,研究其破坏形态、剪切强度和峰值应变等,并与人工砂天然粗骨料混凝土(以下称天然混凝土)试件进行性能对比,分析人工砂取代率对试件剪切性能的影响。试验结果表明,人工砂再生混凝土和天然混凝土有一致的脆性剪切破坏形态,但人工砂再生混凝土的抗剪强度低于天然混凝土的结果,降低幅度一般约在20%以内,且其抗剪强度随人工砂取代率的改变呈现出低、高取代率时相对较高,中间范围的取代率时相对较低的分布趋势,即两头高中间低;人工砂再生混凝土剪应力—剪应变曲线形态与天然混凝土相似,其峰值应变亦随抗剪强度的增加而呈增大的趋势,但曲线斜率低于天然混凝土的情况。更多还原

【Abstract】 In order to study the shear behavior of RACAS(recycled aggregate concrete with artificial sand),36 uniform depth beams were designed in the experiment.Two strength grades(C35 and C45) and different artificial sand replacement rates(0%,30%,50%,70% and 100%) were considered.The failure pattern,shear strength and peak strain of the specimens were analyzed under continuous vertical loading.The experimental results were compared with those of the natural concrete(with natural coarse aggregate and artificial sand fine aggregate) specimens,so the influence of the artificial sand replacement rates on shear performance could be found.Experimental results showed that the shear strengths of the RACAS were lower than those of the nature ones,and the decreasing extents were about less than 20%.Replacement rates of artificial sand had a certain influence on the shear strength.When artificial sand replacement ratios ranged from 30% to 70%,the cube compressive and shear strength were lower than those of other replacement ratios.The relationship of shear force and shear strain or shear force-shear strain curve of the RACAS was similar to that of the nature concrete,and the peak strain of the RACAS raised with the increase of the shear strength,but the slope of the curves was lower.Typical brittle fracture failure was observed in the RACAS specimens,shared a similar failure pattern with the nature concrete.更多还原