Abstract
This paper presents the results of fatigue crack growth rate measurements for three commonly used bridge steels under conditions that simulate those occurring in highway bridges. three different typesof loading were investigated to eliminate any effect of crack closure on the measurements. it was found that the rate of crack propagation is dependent on the dead load stresses present in a structure. one equation should be used for fatigue life prediction in locations experiencing low dead loads, and another for locations with high dead loads. this paper appears in transportation research record no. 1290, third bridge engineering conference, march 10-13, 1991, denver, colorado, volume 1.