粉煤灰对低水胶比混凝土体积稳定性的影响  

EFFECT OF FLY ASH ON VOLUME STABILITY OF LOW WATER-BINDER RATIO CONCRETE

作　　者：韩宏伟 HAN Hongwei(Heilongjiang Institute of Urban-Rural Development,Harbin 150070,China)

机构地区：[1]黑龙江省城乡建设研究所,哈尔滨150070

出　　处：《低温建筑技术》2020年第8期32-34,52,共4页Low Temperature Architecture Technology

摘　　要：研究粉煤灰用量对低水胶比混凝土早期自收缩、塑性收缩开裂和长期干缩的影响。试验结果表明,粉煤灰的使用有效提高了低水胶比混凝土的体积稳定性,混凝土在塑性阶段裂缝出现的时间随着粉煤灰掺量的增加而延后,塑性收缩裂缝的最大宽度、单位面积的总开裂面积和平均开裂面积均出现明显的降低,说明粉煤灰混凝土的早期抗裂能力提高,自收缩率降低幅度较大,其长期干燥收缩率也有所降低;粉煤灰的掺量达到30%时,混凝土的体积稳定性大幅度提高。This paper mainly studies the effect of the content of fly ash on the early plastic shrinkage cracking,the autogenous shrinkage, and long-term drying shrinkage of low water-binder ratio concrete. The results show that the addition of fly ash can effectively improve the volume stability of low water-binder ratio concrete. Moreover, with the content of fly ash increasing, the initial cracking time of concrete is gradually postponed, and the maximum crack width of concrete, the average cracking area, and the total cracking area per unit are significantly reduced. Furthermore, the early anti-cracking capability of the concrete is improved;The autogenous shrinkage rate of concrete is greatly reduced, and the long-term drying shrinkage rate is also reduced. Finally, the volume stability of concrete is greatly enhanced when the content of fly ash reaches 30%.

关 键 词：粉煤灰 混凝土 体积稳定性 收缩开裂 

分 类 号：TU528.31[建筑科学—建筑技术科学]