杭州湾跨海大桥桥墩混凝土耐久性设计方法研究

Research on design method of concrete durability for Hangzhou bay sea bridge

海港混凝土工程因其受海洋环境、气候条件的影响,其结构物需具备良好的工作性和耐腐蚀能力,本文在优选原材料的基础上,通过正交设计方法提出了水化热低、强度高、抗氯离子渗透性好的杭州湾跨海大桥桥墩高耐久性混凝土配合比,并对其影响因素进行了分析。研究结果表明,大掺量优质粉煤灰可以明显降低混凝土的水化温升;复合矿粉与粉煤灰,因其水化热峰值出现时间比单一同量矿物材料水化热峰值出现时间迟一些,有利于防止因水化热引起的混凝土早期开裂,能够提高混凝土的综合耐久性能。

The structure of reinforced concrete for maritime works need have a good workability and corrosion-resistant performance,because of marine environment,climate conditions and so on.Basing on the optimization of raw materials and through the orthogonal method,this paper designed a high durability concrete mix proportion of Hangzhou Bay Sea Bridge pier which is low hydration heat,high strength,good resistance-chloride ion penetration,and analyzed its influencing factors.The results show that high fly-ash concrete can significantly reduce the concrete hydration temperature .Composite slag and fly ash can prevent early concrete cracking cause by concrete hydration and increased the concrete durability,because its hydration peak-appearing time later than the single mineral materials’.