Calibration of reliability index of RC beams for serviceability limit state of maximum crack width

This paper discusses the calibration of reliability index of RC beams in buildings for serviceability limit state of maximum crack width. Based on a group of tests on RC beams for maximum crack width, model uncertainty in complicated expressions for the limit state stipulated by China code for design of concrete structures for concrete beams was estimated. Formulations of the first-order reliability method for evaluating the reliability indexes for this limit state were developed. Sensitivities of the reliability index to the ratio of variable load to permanent load, ratio of reinforcement, section depth, radius of longitudinal reinforcing steel, nominal cover, concrete cube strength, and allowable width limit were discussed.