Analysis and comparison on crack width limit of standards and specifications for concrete bridge members in China and overseas

Crack of concrete is an influential factor to the durability, and it is an evaluation index of concrete bridge durability status. The concrete bridge member's crack width limit on the design stage and operation stage in the specification and standard of China, Japan, the United States of America, New Zealand, UK and other countries are analyzed and compared, characteristics and connotation of the standard limit value are given. The crack width of durability limit value should be consider the environmental effect, steel bar's stress characteristic, component types, crack's position, tectonic characteristics and other related factors. The crack width limit of reinforced concrete structure and prestressed concrete members under general atmospheric environment (alternation of wetting and drying), the general atmosphere environment (no alternation of wetting and drying) and corrosion environment are present. The crack width limit in view of durability are proposed.