Crack Control in Reinforced Concrete Structures Based on Serviceability Limit States

In order to respond to the international demands that require application of the reliability based limit states design, The Korea Highway Bridge Design Code(Limit States Design) has been applied since 2015. This paper presents the design practice of the crack control specifications, which plays a key role in the critical condition verification and durability evaluation, which are important factors, along with the ultimate strength limit state aimed at the safety of the reinforced concrete structures. Maximum crack spacing derived from the formulation using the allowable crack width to satisfy the service condition and the direct crack control to calculate the crack width from the multiplication of the difference between the average strain difference of reinforcing steel and concrete derived from the crack spacing and tension stiffening effect considering the bond characteristics. Indirect crack control, defined as the maximum reinforcing steel diameters and spacings, were also reviewed. In addition, this paper compares with the direct calculation of crack width and indirect crack control specification of the 2012 revised KCI structural concrete design code based on the ultimate strength design method, which is different from the limit states design method.