西堠门公铁大桥C45桩基混凝土配合比设计及性能研究  

Mix Proportion Design and Performance Study of C45 Pile Foundation Concrete of Xihoumen Rail-cum-Road Bridge

作　　者：彭江华 马立超 李信 PENG Jiang-hua;MA Li-chao;LI Xin(The Fifth Engineering Co,Ltd,China Railway Major Bridge Engineering Group Co,Ltd,Jiujiang 332004,China;China Railway Bridge Research Technology Co,Ltd,Wuhan 430050,China)

机构地区：[1]中铁大桥局集团有限公司第五工程有限公司,九江332004 [2]中铁桥研科技有限公司,武汉430050

出　　处：《建材世界》2025年第1期52-55,共4页The World of Building Materials

基　　金：中国中铁股份有限公司科技研究计划开发项目(2020-重点-29).

摘　　要：对近海环境超大直径桩基础C45混凝土的配合比进行了设计,研究了胶凝材料组成对混凝土工作性能、抗压强度、绝热温升及抗氯离子渗透性能的影响规律,并简要分析了其作用机理。结果表明:C45桩基混凝土中掺入粉煤灰可提高混凝土工作性能,适宜掺量的矿粉可有效提高混凝土的和易性,但粉煤灰掺量不够时,矿粉掺量不宜过大;粉煤灰、矿粉的掺入对C45桩基混凝土早期强度不利,但有助于后期强度的提升,矿粉对早期强度和后期强度的贡献均优于粉煤灰;提高粉煤灰、矿粉的掺量可有效降低混凝土的绝热温升,且粉煤灰的作用效果优于矿粉,粉煤灰和矿粉掺量均为30%的C45桩基混凝土绝热温升仅为45.4℃;粉煤灰和矿粉均能改善混凝土的孔结构,提高混凝土密实度,从而提高混凝土的抗氯离子侵蚀性能,且掺量越高效果越显著。The mix ratio of C45 concrete for super-large diameter pile foundation in offshore environment is designed,and the influence of cementitious material composition on concrete working performance,compressive strength,adiabatic temperature rise and chloride ion erosion resistance is studied,and its mechanism is briefly analyzed.The results show that adding fly ash to C45 pile concrete can improve the working performance of concrete,and the appropriate amount of mineral powder can effectively improve the workability of concrete,but the amount of mineral powder should not be too large when the amount of fly ash is not enough.The addition of fly ash and mineral powder has adverse effect on the early strength of C45 pile concrete,but is helpful to the later strength improvement.The contribution of mineral powder to the early strength and later strength is better than that of fly ash.Increasing the content of fly ash and mineral powder can effectively reduce the adiabatic temperature rise of concrete,and the effect of fly ash is better than that of mineral powder.The adiabatic temperature rise of C45 pile concrete with 30%content of fly ash and mineral powder is only 45.4℃.Both fly ash and mineral powder can improve the pore structure of concrete,improve the compactness of concrete,and thus improve the chloride ion erosion resistance of concrete,and the higher the dosage,the more significant the effect.

关 键 词：工作性能 抗压强度 绝热温升 抗氯离子渗透 

分 类 号：U443.15[建筑科学—桥梁与隧道工程]