泵送混凝土不同离析程度的关键性能对比研究  

Comparative Study on Key Properties of Pumped Concrete with Different Degrees of Segregation

作　　者：刘磊 胡承彪 江国富 LIU Lei;HU Chengbiao;JIANG Guofu(Poly Changda Overseas Enineering Co.,Ltd.)

机构地区：[1]保利长大海外工程有限公司

出　　处：《广东建材》2024年第9期21-25,共5页Guangdong Building Materials

摘　　要：泵送混凝土生产与施工中常出现离析不良现象,主要由于外加剂与原材料的适应性不足引起。减水剂作用的过量发挥,时常导致不同程度的离析。本文通过控制外加剂超掺的方式,获得不同离析程度的混凝土,并对其进行拌合物物理性能与强度性能方面进行研究,结果显示外加剂由0超掺至20%,混凝土离析率由7.1%增加至18.9%,超掺10%时,拌合就出现明显浆石分离。尽管混凝土的坍落度和扩展度均增加,但是粘度的增加使倒置坍落度筒排空时间大幅增加,初凝时间也大幅延长,但是混凝土容重增加、含气量减小,因此离析率为18.9%的混凝土7天、28天抗压强度相对正常的组分提高23.8%、19.7%。Segregation is often encountered in the production and construction of pumped concrete,mainly caused by insufficient compatibility between admixtures and raw materials.Excessive reaction of the superplasticizer,which often leads to different degrees of segregation.This paper studies the segregation of concrete by controlling the overdose of admixtures,obtaining concrete with different degrees of segregation.The results show that as the admixture overdose increases from 0%to 20%,the segregation rate of concrete increases from 7.1%to 18.9%.When the overdose is 10%,the mixing process begins to show obvious separation of slurry and stones.Despite the increase in both slump and expan‐sion of the concrete,the increase in viscosity resulted in a substantial increase in the emptying time of the inverted slump cylinder and a substantial increase in the time of initial setting.However,the concrete density increases and the air content decreases,so the 7days and 28days compressive strength of concrete with segregation rate of 18.9%is 23.8%and 19.7%higher than the normal one.

关 键 词：泵送混凝土 离析 拌合物性能 离析率 

分 类 号：TU528.53[建筑科学—建筑技术科学]