STRESS-CONCENTRATION AND FATIGUE OF PROFILED REINFORCING STEELS

Stress concentrations arise from profiles of ribbed reinforcing steel bars and in this study the results of calculated stress concentration factors (SCF), by using finite element method, are related to the fati gue test results. It is apparent that the degree of confinement of a r ibbed bur embedded in concrete not only affects the magnitude of the u ltimate bond stress but also the bond stress-slip relation. Thus the r ib geometry or profile pattern is designed for optimum bond characteri stics and not for fatigue considerations. However the rib geometry inf luences the fatigue performance through the SCFs arising from the root radius, width and flank angles of the profiles. It is shown that thes e latter factors have a significant influence on the fatigue behaviour of reinforcing steel bars. (C) 1998. Published by Elsevier Science Lt d. All rights reserved.