跨海大桥预制墩台大体积海工混凝土质量控制关键技术——以厦门翔安大桥为例  

Key Technologies for Quality Control of Large Volume Concrete for Prefabricated Piers and Abutments of Cross Sea Bridges-Taking Xiamen Xiang'an Bridge as an Example

作　　者：蔡秀娟 CAI Xiujuan(Xiamen Hecheng Engineering Testing Co.,Ltd.,Xiamen 361027,China)

机构地区：[1]厦门合诚工程检测有限公司,厦门361027

出　　处：《铁道勘察》2024年第6期108-115,共8页Railway Investigation and Surveying

摘　　要：为提高大型墩台混凝土结构的耐久性,防止混凝土开裂,以厦门翔安大桥工程为依托,从混凝土配合比优化设计、温度控制等方面,研究跨海大桥预制墩台大体积海工混凝土的质量控制技术措施。其中,配合比优化设计方面,综合考虑海工混凝土和大体积混凝土的特点,以耐久性为核心,以各项性能指标均衡发展为目标,遵循抗氯离子渗透性与抗裂性并重原则,采用低热硅酸盐水泥、适中水胶比、较大掺量优质粉煤灰及矿渣粉掺合料以及高性能减水剂,再通过计算、试配、试验和优化调整,从中优选各项技术指标符合要求、综合性能最佳的混凝土配合比等质量控制措施;温度控制方面,综合考虑大体积混凝土在浇筑初期水泥产生大量水化热、易受外界气温变化影响、混凝土硬化后体积收缩变形较大的特点,采取做好原材料降温、严控混凝土入模温度、优化浇筑工艺、加强浇筑后温度控制、注重养护工作等温控防裂措施。室内试验和实体检测结果表明,混凝土工作性能、力学性能、耐久性、密实性、抗裂性及体积稳定性等有关技术指标均符合设计及规范要求,实践证明,大型预制墩台的混凝土配合比优化设计与温度控制措施可行。In order to improve the durability of large pier and abutment concrete structures and prevent concrete cracking,based on the Xiamen Xiang'an Bridge project,this paper analyzed and studied the quality control technical measures of prefabricated pier and abutment large volume marine concrete for cross sea bridges from the aspects of concrete mix proportion optimization design and temperature control.In terms of mix proportion optimization design,the characteristics of marine concrete and large volume concrete were comprehensively considered,with durability as the core and balanced development of various performance indicators as the goal.Following the principle of equal emphasis on resistance to chloride ion penetration and crack resistance,low heat silicate slurry,moderate water cement ratio,high dosage high-quality fly ash and slag powder admixture,and high-performance water reducer were mainly used.Through calculation,trial mixing,testing,and optimization adjustment,the concrete mix proportion that met the requirements and had the best comprehensive performance were selected as the quality control measure.In terms of temperature control,the characteristics of large volume concrete,such as the large amount of hydration heat generated by cement during the initial pouring stage,susceptibility to external temperature changes,and significant volume shrinkage deformation after concrete hardening,were comprehensively considered.The main measures taken included cooling the raw materials,strictly controlling the temperature of concrete entering the mold,optimizing the pouring process,strengthening temperature control after pouring,and paying attention to maintenance work to control temperature and crack prevention.The results of indoor tests and physical inspections show that,the technical indicators related to the workability,mechanical properties,durability,compactness,crack resistance,and volume stability of concrete meet the design and specification requirements.Practice has proved that the optimization design of con

关 键 词：跨海大桥 大型预制墩台 大体积混凝土 混凝土配合比 温控防裂措施 

分 类 号：U448.1[建筑科学—桥梁与隧道工程] U448.3[交通运输工程—道路与铁道工程]