九江长江公路大桥索塔高性能粉煤灰混凝土的早期抗裂与长期变形性能  

Early-Age Crack Resistance and Long-Term Deformation of High Performance Fly Ash Concrete for Cable Support Tower in Jiujiang Yangtze River Highway Bridge

作　　者：万纯斌[1] 唐凯[2] 何伟兵[1] 李北星[2] 屠柳青 

机构地区：[1]江西省交通运输厅九江长江公路大桥项目建设办公室,九江市332000 [2]武汉理工大学硅酸盐建筑材料国家重点实验室,武汉市430070 [3]中交武汉港湾工程设计研究院有限公司,武汉市430040

出　　处：《公路》2012年第9期168-172,共5页Highway

基　　金：江西省交通运输厅科技项目;项目编号2010C00009

摘　　要：结合九江长江公路大桥索塔工程,对掺粉煤灰的高性能混凝土配合比的早期开裂敏感性与长期变形性能进行了试验。结果显示,与同强度等级未掺粉煤灰的混凝土相比,掺入质量分数22.5%的Ⅰ级粉煤灰等量取代硅酸盐水泥配制的C50混凝土,其不仅具有良好的工作性能和力学性能,且水化热温升和早期自收缩下降、温度应力储备增加、抗塑性收缩开裂能力提高;同时,长期干燥收缩和徐变降低。掺入0.75kg/m3聚丙烯纤维可进一步提高其早期抗裂性能。Combined with the cable support tower engineering practice of Jiujinag Yangtze River Ex- pressway Bridge , the early-age crack sensitivity and long-term deformation of high performance fly ash concrete are investigated. The results show that the C50 concrete with 22.5 % grade Ⅰ fly ash as the sub- stitution of Portland cement has not only better workability and mechanical strength, but also the lower hydration heat, less early-age autogenous shrinkage, higher temperature stress reserve and improved plas- tic shrinkage crack resistance, compared with the reference concrete with the same strength grade but without fly ash. Furthermore, the fly ash concrete has lower drying shrinkage and creep deformation. The incorporation of 0.75 kg/m^3polypropylene fibre further reinforced the crack resistance of the concrete .

关 键 词：索塔 高性能混凝土 粉煤灰 抗裂性 长期变形 

分 类 号：U414.101[交通运输工程—道路与铁道工程]