采用PF-UHPC制备钢混组合梁桥面板施工关键技术  

Key Construction Technology for Steel-concrete Composite Beam Bridge Decking Prepared with PF-UHPC

作　　者：杨元海 王斌 黄卿维[3] YANG Yuan-hai;WANG Bin;HUANG Qing-wei(China Communications Road and Bridge Construction Co.,Ltd.,Beijing 100027,China;China Communications Road and Bridge South China Engineering Co.,Ltd.,Zhongshan,Guangdong,528403,China;College of Civil Engineering,Fuzhou University,Fuzhou,Fujian 350100,China)

机构地区：[1]中交路桥建设有限公司,北京100027 [2]中交路桥华南工程有限公司,广东中山528403 [3]福州大学土木工程学院,福建福州350100

出　　处：《公路交通科技》2024年第4期120-131,共12页Journal of Highway and Transportation Research and Development

摘　　要：为探明不同技术指标对钢混组合梁UHPC桥面板性能的影响,完善超高性能混凝土预混料(PF-UHPC)的制备技术工艺,制造出性能稳定、满足施工要求的钢混组合梁UHPC桥面板,通过试验对比分析了不同工艺技术指标对PF-UHPC工作性能及力学性能的影响。确定最佳工艺技术指标,形成一套关于PF-UHPC预制和现浇钢混组合梁桥面板施工的关键技术。结果表明:PF-UHPC基准配合比的强度、工作性能均满足要求,且增加减水剂掺量0.3%能显著改善材料工作性能而不影响力学性能;采用大搅拌机搅拌时长为8 min时,混合料各项性能最佳;材料凝结时间受室内外环境因素影响大;钢纤维的投料先后对材料工作性能和力学性能影响较小,但后加钢纤维的混合料其钢纤维均匀性偏差较大;试件抗折强度受钢纤维取向影响,而钢纤维取向主要取决于布料方向,布料方向与UHPC流动方向的角度越大,试验板的抗折强度越低;振捣频率对UHPC抗折强度影响较大,对抗压强度和钢纤维含量偏差影响较小,80 Hz振捣频率最有利;UHPC湿养护后水化热温度基本在40~50℃,内部初始温度随板厚增加升高,蒸养过程中UHPC板中心升温较外部慢,内外温差较大;蒸养棚内恒温温度宜控制在90℃以上,且应适当延长自然降温时间,25 cm厚板底部在70℃以上恒温30 h,其强度满足设计要求。In order to investigate the influence of different technical indicators on the performance of UHPC bridge decking in steel-concrete composite beams,to improve the preparation technology of premix for UHPC(PF-UHPC),and to produce steel-concrete composite beams with stable performance and meeting construction requirements,the influences of different technical indicators on the working performance and mechanical properties of PF-UHPC are compared and analyzed through experiments.The optimal technical indicators are determined,and a set of key technologies is developed for the construction of prefabricated and cast-in-place steel-concrete composite beam bridge decking with PF-UHPC.The result shows that the strength and working performance of the PF-UHPC base mix proportion meet the requirements,and increasing 0.3%dosage of water reducer can significantly improve the material’s working performance without affecting its mechanical properties.When using a large mixer with a mixing time of 8 min,the best performance of the mixture is achieved.The setting time of materials is greatly influenced by indoor and outdoor environmental factors.The feeding sequence of steel fibers has a relatively small influence on the working performance and mechanical properties of the material,but the mixture with added steel fibers has a significant deviation in the uniformity of steel fibers.The flexural strength of the specimen is influenced by the orientation of steel fibers,which mainly depends on the direction of fabric.The greater the angle between the fabric direction and the flow direction of UHPC,the lower the flexural strength of the test decking.The vibration frequency has a significant influence on the flexural strength of UHPC,but has a smaller influence on the deviation of compressive strength and steel fiber content,and the 80 Hz vibration frequency is the most favorable.The hydration heat temperature of UHPC after wet curing is basically between 40℃and 50℃,and the initial internal temperature increases with the increas

关 键 词：桥梁工程 施工技术 控制变量法 UHPC桥面板 工作性能及力学性能 

分 类 号：U445[建筑科学—桥梁与隧道工程]