摘要
为探究不同粗骨料取代率对机制砂再生混凝土(RCM)高温性能的影响,以不同粗骨料取代率(0%、20%、40%、60%、80%、100%,质量分数)制备RCM并研究其单面受高温后的表面形貌、质量损失率、抗压强度、荷载变形曲线及微观形貌。结果表明,粗骨料取代率在40%~60%时,在低于600℃的高温试验下RCM表现良好。当温度在200℃时,各组试块表面形貌变化不大,质量损失率较小,抗压强度略微上升;当温度在400℃时,各组试块表面开始出现裂缝,质量损失率为4.35%~6.47%,抗压强度开始下降,此时粗骨料取代率影响不大;当温度达到600℃时,表面形貌变化明显,质量损失率上升到6.42%~8.70%,抗压强度最终降低到基准强度的80%左右,此时粗骨料取代率在40%~60%的试块表现良好;当温度达到800℃时,各组试块表面形貌变化进一步加剧,粗骨料取代率大于60%的试块受影响非常明显,同时各类性能参数表明混凝土已完全丧失工作性能。
To explore the influences of different coarse aggregate replacement ratios on the high-temperature performance of recycled concrete with manufactured sand(RCM),RCM specimens were prepared with varying coarse aggregate replacement ratios(0%,20%,40%,60%,80%,100%,mass fraction).The surface morphology,mass loss rate,compressive strength,load-deformation curve,and microscopic morphology of RCM were investigated after exposure to high temperatures.Results indicate that the RCM performs well in high-temperature tests below 600℃when the coarse aggregate replacement ratio is between 40%and 60%.At 200℃,the specimens in each group show minimal morphological changes,small mass loss rate,and a slight increase in compressive strength.At 400℃,cracks begin to appear on the surface of the specimens,with mass loss rate ranging from 4.35%to 6.47%,and compressive strength starts to decline.At this point,the coarse aggregate replacement ratio has a minor impact.At 600℃,significant changes in surface morphology are observed,with mass loss rate increasing to 6.42%~8.70%,and compressive strength eventually decreasing to around 80%of the baseline strength.Specimens with coarse aggregate replacement ratio of 40%~60%perform well under these conditions.At 800℃,the surface morphology of specimens in all groups intensifies further.The impact becomes particularly pronounced for coarse aggregate replacement ratio exceeding 60%.Simultaneously,various performance parameters indicate that the concrete has experienced a complete loss of effectiveness at this temperature.
作者
王发静
王新杰
朱平华
刘啸林
WANG Fajing;WANG Xinjie;ZHU Pinghua;LIU Xiaolin(School of Urban Construction,Changzhou University,Changzhou 213164,China)
出处
《硅酸盐通报》
CAS
北大核心
2024年第6期2084-2092,共9页
Bulletin of the Chinese Ceramic Society
基金
江苏省研究生科研创新计划(KYCX23_3096)。
关键词
机制砂再生混凝土
粗骨料取代率
高温性能
抗压强度
荷载变形曲线
recycled concrete with manufactured sand
coarse aggregate replacement ratio
high-temperature performance
compressive strength
load-deformation curve
