再生混凝土轴心抗压强度与变形性能试验研究

Experimental study on axial compression strength and deformation performance of recycled aggregate concrete

摘要：为了研究再生混凝土的轴心抗压强度与变形性能，利用压碎后的立方体试块作为再生粗骨料原料，配制了4种不同粗骨料替代率的再生混凝土，替代率从0-100％变化，共计12个棱柱体试块在电液伺服试验机上加载，观察了其破坏过程和破坏形态，并获取了其荷载-位移全过程曲线，并对各种骨料替代率再生混凝土的荷载-位移全过程曲线进行分析。结果表明：再生骨料混凝土与天然骨料混凝土的破坏过程和形态相似，随着再生粗骨料取代率的增加，再生混凝土的峰值应力和峰值应变分别呈现出二次函数和三次函数的关系。再生粗骨料取代率对再生混凝土的应力-应变全曲线有较大影响，随着再生粗骨料取代率的增加，再生混凝土的弹性模量逐渐变大，再生混凝土的延性和耗能总体上越来越好。随着再生粗骨料取代率的增加，无量纲化的应力-应变曲线上升段越来越陡，当再生粗骨料的取代率为100％时，无量纲化曲线下降段非常平缓，试件的后期变形性能非常良好。

In order to study axial compression strength and deformation performance of recycled aggregate concrete, four recycled aggregate concrete of different replacement ratios was prepared using crushed cube block as recycled coarse aggregate.Replacement ra- tios varied from 0 to 100%, and a total of 12 prismatic blocks were loaded on the electro-hydraulic servo testing machine.The destruc- tion process and failure mode were observed,the load-displacement curves of the whole process were obtained and analyzed.It is shown that destruction process and failure mode of recycled aggregate concrete and natural aggregate concrete are similar to each oth- er.With the increase of recycled coarse aggregate replacement ratio, peak stress and peak strain of recycled aggregate concrete show the relations of quadratic function and cubic function respectively.Replacement ratio of recycled coarse aggregate makes a greater im- pact on stress-strain curves of recycled aggregate concrete, with the increase of recycled coarse aggregate replacement ratio, elastic modulus of recycled aggregate concrete gradually become larger, ductility and energy performance of recycled aggregate concrete get better on the whole.With the increase of recycled coarse aggregate replacement ratio, the ascent of dimensionless stress-strain curve get more steep, when replacement ratio is 100%, the falling section of the dimensionless curve is very gentle, and deformation proper- ties of late stage is very good.