Title:
Experimental and Analytical Evaluation of Reinforced Concrete Girders under Low-Cycle Shear Fatigue
Author(s):
Richard W. B. Forrest, Christopher Higgins, and A. Ekin Senturk
Publication:
Structural Journal
Volume:
107
Issue:
2
Appears on pages(s):
199-207
Keywords:
bridge; fatigue; girder; reinforcement steel; shear.
DOI:
10.14359/51663536
Date:
3/1/2010
Abstract:
Increasing load magnitudes and volume over time, the coincidence of multiple permit loads, and the advent of modern superloads motivated by socioeconomic and political considerations creates the potential for low-cycle fatigue in conventionally reinforced concrete bridge girders lightly reinforced for shear. Six full-scale reinforced concrete girder specimens representative of those found in 1950s vintage reinforced concrete deck-girder bridges were tested under low-cycle fatigue conditions. The specimens were tested in both T and inverted-T (IT) configurations. Other test variables included stirrup spacing, flexural reinforcing details, and spacing of supports. Low-cycle fatigue produced bond deterioration and cumulative plasticity of stirrups. Progressive fracture of stirrup reinforcement under low-cycle fatigue led to eventual specimen failure. A methodology for the analysis of low-cycle fatigue in girders is proposed using the finite element method (FEM) to approximate stirrup stress ranges and a linear damage model to estimate the life of a conventionally reinforced concrete girder under repeated overloads.