Next Article in Journal
Molecularly Imprinted Polymers Based Electrochemical Sensor for 2,4-Dichlorophenol Determination
Next Article in Special Issue
Dynamic and Static Behavior of Hollow-Core FRP-Concrete-Steel and Reinforced Concrete Bridge Columns under Vehicle Collision
Previous Article in Journal
Influence of Carbon Nanotube Coatings on Carbon Fiber by Ultrasonically Assisted Electrophoretic Deposition on Its Composite Interfacial Property
Previous Article in Special Issue
Fiber Reinforced Polymer Strengthening of Structures by Near-Surface Mounting Method
Article Menu
Issue 8 (August) cover image

Export Article

Open AccessArticle
Polymers 2016, 8(8), 308; doi:10.3390/polym8080308

A Retrofit Theory to Prevent Fatigue Crack Initiation in Aging Riveted Bridges Using Carbon Fiber-Reinforced Polymer Materials

1
Empa, Swiss Federal Laboratories for Materials Science and Technology, Structural Engineering Research Laboratory, Überlandstrasse 129, Dübendorf 8600, Switzerland
2
School of Civil Engineering, University of Tehran, Tehran 1417466191, Iran
*
Author to whom correspondence should be addressed.
Academic Editor: Russell E. Gorga
Received: 8 June 2016 / Revised: 25 July 2016 / Accepted: 11 August 2016 / Published: 18 August 2016
(This article belongs to the Special Issue Selected Papers from “SMAR 2015”)
View Full-Text   |   Download PDF [5772 KB, uploaded 18 August 2016]   |  

Abstract

Most research on fatigue strengthening of steel has focused on carbon fiber-reinforced polymer (CFRP) strengthening of steel members with existing cracks. However, in many practical cases, aging steel members do not yet have existing cracks but rather are nearing the end of their designed fatigue life. Therefore, there is a need to develop a “proactive” retrofit solution that can prevent fatigue crack initiation in aging bridge members. Such a proactive retrofit approach can be applied to bridge members that have been identified to be deficient, based on structural standards, to enhance their safety margins by extending the design service life. This paper explains a proactive retrofit design approach based on constant life diagram (CLD) methodology. The CLD approach is a method that can take into account the combined effect of alternating and mean stress magnitudes to predict the high-cycle fatigue life of a material. To validate the retrofit model, a series of new fatigue tests on steel I-beams retrofitted by the non-prestressed un-bonded CFRP plates have been conducted. Furthermore, this paper attempts to provide a better understanding of the behavior of un-bonded retrofit (UR) and bonded retrofit (BR) systems. Retrofitting the steel beams using the UR system took less than half of the time that was needed for strengthening with the BR system. The results show that the non-prestressed un-bonded ultra-high modulus (UHM) CFRP plates can be effective in preventing fatigue crack initiation in steel members. View Full-Text
Keywords: carbon fiber-reinforced polymer; bonded; unbonded; high-cycle fatigue life; prevention of crack initiation; rehabilitation; old steel members; riveted metallic bridges; constant life diagram; strengthening carbon fiber-reinforced polymer; bonded; unbonded; high-cycle fatigue life; prevention of crack initiation; rehabilitation; old steel members; riveted metallic bridges; constant life diagram; strengthening
Figures

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Ghafoori, E.; Motavalli, M. A Retrofit Theory to Prevent Fatigue Crack Initiation in Aging Riveted Bridges Using Carbon Fiber-Reinforced Polymer Materials. Polymers 2016, 8, 308.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Polymers EISSN 2073-4360 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top