砂率对高强再生混凝土的力学及干燥收缩性能影响研究  

Research on the effect of sand ratio on the mechanical and drying shrinkage properties of high strength recycled concrete

作　　者：王欣 WANG Xin(Department of Engineering Management,Shanxi Vocational University of Engineering Science and Technology,Taiyuan 030031,China)

机构地区：[1]山西工程科技职业大学工程管理系,山西太原030031

出　　处：《中国测试》2023年第4期159-164,共6页China Measurement & Test

摘　　要：再生混凝土的综合利用可缓解矿石资源压力,实现低碳循环可持续经济。该研究采用砂率(34%,36%,38%,40%)和再生骨料替代率(0,30%,50%)为控制变量,以抗压强度、抗拉强度、抗折强度及干燥收缩变形为指标,详细探讨砂率和再生骨料替代率对高强再生混凝土的性能影响规律。研究表明:高强再生混凝土的力学强度均随着再生粗骨料的增加而逐渐降低,适量的砂率会产生高强度的再生混凝土坍落度,可以提升再生混凝土的密实度,脆性和塑性变形能力,并提高其力学强度。高强度再生混凝土的干缩率变化率在90 d后逐渐趋于稳定,砂率和干缩率的变化呈良好的线性关系。增加砂的比例能在一定程度上降低再生粗骨料对高强度再生混凝土干缩的影响。The comprehensive utilization of recycled concrete can alleviate the pressure of ore resources and achieve a sustainable economy with a low carbon cycle.In this study,sand rate(34%,36%,38%,40%)and recycled aggregate replacement rate(0,30%,50%)were used as control variables.Compressive strength,tensile strength,flexural strength,and The drying shrinkage deformation is used as an index.The influence of sand rate and recycled aggregate replacement rate on the performance of high-strength recycled concrete is specifically explored.Studies have shown that a moderate amount of sand yields high slump in recycled concrete.With the increase of recycled coarse aggregate,the compressive,tensile and flexural strength of high-strength recycled concrete decreases.Proper sand ratio can improve the compactness,brittleness and plastic deformation ability of high-strength recycled concrete,and increase its mechanical strength.The change rate of dry shrinkage rate of high-strength recycled concrete gradually stabilized after 90 days,and the change of sand speed and dry shrinkage rate showed a good linear relationship.Increasing the proportion of sand may reduce the effect of recycled coarse aggregate on dry shrinkage of high-strength recycled concrete to a certain extent.

关 键 词：高强再生混凝土 砂率 再生粗骨料取代率 力学性能 干燥收缩 

分 类 号：TU528[建筑科学—建筑技术科学] TB9[一般工业技术—计量学]