摘要
为了研究矿物掺合料对超高性能混凝土(UHPC)性能的影响,以及矿物掺合料在超高性能混凝土中应用可行性,将矿物掺合料复配到C120超高性能混凝土体系中替代部分水泥,研究性能影响规律以及得到应用最佳比例。结果表明:(1)最小需水量试验及标准稠度试验得到矿物掺合料最佳占比为水泥∶矿粉∶粉煤灰∶硅灰=0.7∶0.1∶0.1∶0.1。(2)粉煤灰对扩展度的影响较为显著,可使扩展度最大提升62 mm;矿粉能显著增强早期强度,最高可使早期强度增加8 MPa;硅灰则对后期强度有较为明显的作用,后期强度最高可提高5 MPa。(3)经对矿物掺合料复合胶凝材料体系的研究,确定了最优配合比,即水泥、矿粉、粉煤灰、硅灰的比例为0.75∶0.10∶0.05∶0.10,在此配合比下,扩展度可达610 mm,28 d抗压强度为126.77 MPa。(4)SEM表明,掺矿物掺合料的硬化体更密实,钢纤维包裹性更强。
In order to study the effect of mineral admixtures on the performance of ultra-high performance concrete(UHPC)and the feasibility of using mineral admixtures in UHPC,mineral admixtures were compounded into the C120 ultra-high performance concrete system to replace some cement,and the performance influence law was studied to obtain the optimal application ratio.The results showed that(1)The optimal proportion of mineral admixture was obtained through the minimum water demand test and standard consistency test,with cement∶mineral powder∶fly ash∶silica fume=0.7∶0.1∶0.1.(2)The influence of fly ash on the expansion degree is significant,which can increase the maximum expansion degree by 62 mm.Mineral powder can significantly enhance early strength,with a maximum increase of8 MPa in early strength.Silica fume has a significant effect on the later strength,and the highest later strength can be increased by5 MPa.(3)After studying the mineral admixture composite cementitious material system,the optimal ratio was determined,which is 0.75∶0.10∶0.05∶0.10 for cement,mineral powder,fly ash,and silica fume.Under this ratio,the expansion can reach 610 mm and the 28 day compressive strength is 126.77 MPa.(4)SEM shows that the addition of mineral admixtures results in a denser hardened body and stronger steel fiber wrapping.
作者
王青沙
WANG Qingsha(Shanxi Vocational and Technical College,Taiyuan 030006,China)
出处
《混凝土》
北大核心
2025年第2期188-192,共5页
Concrete
关键词
矿物掺合料
超高性能混凝土
最小需水量
标准稠度
扩展度
抗压强度
mineral admixtures
ultra-high performance concrete
minimum water requirement
standard consistency
expansion
compressive strength
