An experimental investigation of the behaviour of heat-damaged RC columns confined with CFRP fabrics using photogrammetry

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• 作者：Yaman S. S. Al-Kamaki ; Riadh Al-Mahaidi ; Ian Bennetts
• 刊名：Materials and Structures
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：50
• 期：1
• 全文大小：4,677 KB
• 刊物类别：Engineering
• 刊物主题：Structural Mechanics
  Theoretical and Applied Mechanics
  Mechanical Engineering
  Operating Procedures and Materials Treatment
  Civil Engineering
  Building Materials
  
• 出版者：Springer Netherlands
• ISSN：1871-6873
• 卷排序：50

文摘

This paper describes an experimental study of the behaviour of unheated and heat-damaged reinforced concrete (RC) circular columns wrapped with carbon fibre reinforced polymer (CFRP) fabric. The purpose of the study was to measure the hoop and axial strain variation over the surfaces of unheated and heat-damaged CFRP-confined RC columns using an innovative digital image correlation technique (DICT), which is a photogrammetric technique. Eighteen large-scale (Ø 204 mm × 750 mm) identical columns were fabricated and tested, of which 12 were heated and cooled under 30 % of maximum load at ambient temperature then wrapped with CFRP fabrics after air cooling. The variables considered in these tests included unheated and heat-damaged columns, number of layers of CFRP sheet, level of heat exposure, and strain variation. It was found that the use of CFRP fabric increases both the compressive strength and the ductility of both unheated and heat-damaged columns. The DICT system was successfully used to determine the variation of both axial and hoop strain distributions along the heights of the columns. Strain gauge data from gauges installed on the concrete/CFRP surfaces at mid-height were consistent with the data taken using photogrammetry at those locations, provided the gauges did not debond. The failure strain of columns confined by CFRP does not occur at the ultimate tensile strains determined from coupon tensile tests defined by the strain efficiency factor.KeywordsCarbon fibre reinforced polymer (CFRP)High-temperature propertiesStructural testingPhotogrammetryStrain efficiency