ASSESSMENT OF PLATE-END DEBONDING DESIGN PROVISIONS FOR RC BEAMS STRENGTHENED WITH FRP

Abstract

DESPITE THE ENHANCEMENT IN THE FLEXURAL CAPACITY OF REINFORCED CONCRETE (RC) MEMBERS EXTERNALLY STRENGTHENED WITH FIBER REINFORCED POLYMER (FRP) COMPOSITES, DEBONDING OF THE FRP FROM THE CONCRETE SUBSTRATE AT ITS ENDS IS A MAJOR CONCERN. THIS PREMATURE FAILURE MOSTLY OCCURS AT A LOW FRACTION OF THE FRP RUPTURE STRAIN, THUS COMPROMISES THE EFFECTIVENESS OF FRP-STRENGTHENING. THIS PAPER PRESENTS A REVIEW ON PLATE-END (PE) DEBONDING AS A CRITICAL FAILURE MODE IN FRP-STRENGTHENED BEAMS. THE AVAILABLE MODELS FOR PREDICTING THIS MODE OF FAILURE ARE ALSO PRESENTED AND ASSESSED AGAINST EXPERIMENTAL DATABASE ESTABLISHED FROM PREVIOUS STUDIES. THE PRECAUTIONS RECOMMENDED BY THE RELEVANT DESIGN CODES TO PREVENT PE DEBONDING ARE ALSO DISCUSSED AND ASSESSED. BASED ON THE ASSESSMENT, SEVERAL CONCLUSIONS ARE EMPHASIZED, INCLUDING THE INACCURACY IN PREDICTIONS OF PE DEBONDING GIVEN BY MOST AVAILABLE MODELS WHEN COMPARED WITH THE EXPERIMENTAL DATABASE AND THE INCONSISTENCY AMONG THESE MODELS. THE ASSESSMENT ALSO REVEALED THAT THE PRECAUTIONS RECOMMENDED BY MOST OF THE DESIGN CODES ARE NOT ADEQUATE TO PREVENT PE DEBONDING.