混凝土结构的耐久性设计方法

长期以来，我国土建工程设计对结构的使用年限未给予足够重视，混凝土结构设计规范在结构耐久性要求上存在许多不足。环境作用下的混凝土结构耐久性设计应考虑多个方面的因素，包括设计使用年限，结构所处环境对钢筋和混凝土的腐蚀作用，耐久混凝土的材料选择与组成，减轻或延迟材料劣化的结构构造措施，保证结构耐久性的施工质量控制以及使用年限内的定期维修与检测等。对氯盐环境下的重要工程如桥梁和港工，还应选用适宜的计算模型进行使用年限的预测。

DURABILITY DESIGN OF CONCRETE STRUCTURES

Service life provisions in structural design have long been ignored in our country.Insufficiencies for durability requirements in current design codes for concrete structures are illustrated.To make the design adequate for concrete structures against environmental effects,many factors should be considered including the design service life,the environmental agents that cause concrete and rebars deterioration,selection of materials and mix-proportion for durable concrete,structural details to mitigate and delay the material degradation,quality control in construction as well as predetermined measures for structure maintenance and inspection in service.Service life prediction based on degradation model is also needed for those important infra-structures such as highway bridges and harbors subjected to chlorides attack.