废旧砖再生骨料混凝土配合比设计的试验研究

摘要

以建筑垃圾废旧砖为原材料制作再生粗骨料和再生细骨料部分取代天然粗骨料和天然细骨料,以粉煤灰和矿粉部分取代水泥配制废旧砖再生骨料混凝土,采用正交试验设计方法进行废旧砖再生骨料混凝土的抗压强度试验,采用极差分析和方差分析确定出各因素影响再生黏土砖混凝土强度的显著性.试验结果表明:最佳配合比为A2B2C2D3;四因素对混凝土抗压强度影响主次顺序为再生粗骨料取代率,粉煤灰取代率,再生细骨料取代率,矿粉取代率;各因素不同水平对再生骨料混凝土强度影响的规律为,混凝土抗压强度随再生粗骨料取代率、粉煤灰取代率和再生细骨料取代率的增大而减小;矿粉取代率在25％时,其强度最大.%Constructional waste bricks were taken as raw material to fabricate recycled coarse and fine aggregates,and substitute natural coarse and fine aggregates;and fly ash and mineral powder were taken to substitute partially the cement and fabricate concrete with recycled aggregate of waste bricks.Four-parameter-four-level orthogonal tests were designed and the compressive strength of the waste brick recycled aggregate concrete was tested.The remarkableness of influence of factors on the compressive strength of the waste brick recycled aggregate concrete were determined with range analysis and variance analysis.The test result shows that the optimal mixture ratio will be A2B2C2D3.The priority of the four factors affecting the compressive strength of concrete will be substitution rate of recycled coarse aggregate,substitution rate of fly ash,substitution rate of recycled fine aggregate,and substitution rate of mineral powder.The rule of influence of various levels of every parameters on compressive strength will be as follows:the compressive strength of concrete decreases with the increase of substitution rates of recycled coarse aggregate,fly ash,and fine aggregate;when the substitution rate of mineral powder is under level 3,the compressive strength of concrete reaches its maximum.