Optimum Rib Design in TMT Rebars to Enhance Fatigue Life While Retaining Bond Strength
Publication: Journal of Materials in Civil Engineering
Volume 30, Issue 3
Abstract
This paper investigates high-cycle fatigue (HCF) failure in thermomechanically treated (TMT) rebars using fractographic analysis. Most fatigue failures are found to initiate at the root of the transverse ribs, irrespective of rebar diameter. Three-dimensional finite-element (FE) analysis is used to study the effect of modifications to the rib geometry on stress concentrations at these critical locations. Modification of the ratio of the radius () of the root of the transverse rib to its height () is found to reduce stress concentrations at the rib root. A procedure combining FE analysis with ideas adapted from notch fatigue is developed to predict the fatigue life of rebars with optimum ratio. The predicted fatigue life of a 16-mm-diameter rebar with optimum ratio is found to be significantly higher than that of the original rebar. Pullout tests reveal that the proposed modification to the rib design does not result in any deterioration in bond strength between rebar and concrete.
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Published In
Journal of Materials in Civil Engineering
Volume 30 • Issue 3 • March 2018
Copyright
©2017 American Society of Civil Engineers.
History
Received: Feb 21, 2017
Accepted: Aug 28, 2017
Published online: Dec 29, 2017
Published in print: Mar 1, 2018
Discussion open until: May 29, 2018
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