Study on Fuzzy Reliability of FRP-Reinforced Concrete Under Serviceability Limit State in Chinese Code

The cracks and deflection of the structure should not affect the normal use of the structure, which was required in the code for the design of reinforced concrete (GB 50010-2010). Though the Code stipulates the limit values of cracks and deflection of components under different control levels, there is a certain fuzziness in this provision for it is difficult to find a clear limit value to distinguish whether the components are normal or not in practical engineering. In addition, according to the JCSS combination rule, in the reliability analysis of the serviceability limit state, when frequent combination and quasi-permanent combination are involved, the corresponding sequence value should be used, instead of the maximum load value multiplied by the combination value coefficient adopted in the unified standard for reliability design of building structures (GB 50068-2001). In addition, for reinforced concrete flexural members, the research on the reliability control level under the serviceability limit state has been quite perfect, but for FRP concrete flexural members, the calculation formula follows the reinforced concrete code, and most of the research is devoted to the parameter research in the calculation formula, and the research on the reliability control level is less. Considering the above shortcomings, the fuzzy theory with the random process theory to analyze the reliability of cracks was combined in this paper. The calculation results of the example indicate that the reliability analysis method considering fuzzy factors and random process theory is reasonable.