휨 또는 쪼갬인장 반복하중을 받는 콘크리트의 신뢰성 해석과 피로모델 제안

Abstract

This paper compares the fatigue behaviors of concretes subjected to flexural and split-tensional loadings, and proposes the fatigue reliability models based on experimental results and reliability analysis. The fatigue tests were performed for the specimens of split tensional cylinders and flexural beams under constant loadings at three levels (70, 80 and ) with 0.1 stress ratio, 20 Hz loading speed and sine wave. The reliability analysis on fatigue data was based on Weibull distribution of two-parameters. From fatigue test results, two criteria were proposed to reject the experimental fatigue data because of statistical variation of concrete fatigue data. Two parameters (and u) of Weibull distribution were obtained using graphical method, moment method and maximum likelihood method. The probability density function(P.D.F) and cumulative distribution function(C.D.F) of the Weibull distribution for fatigue life of pavement concrete were derived for various stress levels using parameters, and u. The goodness-of-fit test by Kolmogorov-Smirnov test was acceptable at level of significance. Based on reliability analysis, a fatigue model for pavement concrete was proposed and compared from existing models.