文冲船厂3号坞为重力式结构,最大块体厚约5m。主体工程混凝土量约60000m~3,其实际浇筑期仅有9个月。该坞的块体尺寸,具有仓面及体积大、技术要求高的特点,存在着约束温差应力、收缩应力共同作用的组合应力作用。工程存在着块体产生裂缝和渗、漏的危险。为确保工程质量、如期交付使用,在技术上采取了一系列降低约束应力,提高混凝土结构抗裂能力的措施。降低块体约束,提高结构抗裂能力的措施之一是,在混凝土内掺缓凝减水性外加剂 Wenchong Shipyard No. 3 dock gravity structure, the largest block thickness of about 5m. The main project of concrete about 60000m ~ 3, the actual pouring period of only 9 months. The dock block size, with a large warehouse and large size, high technical requirements, there is constrained temperature stress, shrinkage stress combined role of the combined stress. There is a risk of cracks and seepage and leakage in the block. To ensure the quality of the project, delivered on schedule, technically adopted a series of measures to reduce the constraint stress and improve the cracking resistance of concrete structures. One of the measures to reduce the block constraints and improve the crack resistance of the structure is to mix the retarding water-reducing admixture