IR thermography for interface analysis of FRP laminates externally bonded to RC beams

Non-destructive (ND) evaluation by thermographic analysis was applied to reinforced concrete (RC) beams strengthened with CFRP laminates, to assess the quality of the interface between reinforcement and substrate before and under loading, during laboratory bending tests. The proper algorithm for processing data acquired from the thermographic system was first selected by testing reduced-scale fiber reinforced polymer (FRP)-strengthened concrete slabs with artificial defects and anomalies, deliberately placed at the interface. Portable heating equipment was purposely set-up to allow continuous scanning along the loaded beams. Results showed that infrared thermography (IRT) can supply significant qualitative and quantitative information on bonding of FRP materials applied to structural substrates, for both preliminary and in-situ investigations, by means of a reliable low-time-consuming procedure. Cross-evaluation of crack patterns during bending tests and thermographic results are also presented.

[1]  Matthew B. Blaschko,et al.  Externally bonded FRP reinforcement for RC structures , 2001 .

[2]  L. Lorenzis,et al.  BOND OF FRP LAMINATES TO CONCRETE , 2001 .

[3]  Claudio Modena,et al.  FRP Shear Strengthening of RC Beams with Transverse Steel Reinforcement , 2002 .

[4]  Jian fei Chen,et al.  Anchorage strength models for FRP and steel plates bonded to concrete , 2001 .

[5]  V. M. Malhotra,et al.  CRC Handbook on Nondestructive Testing of Concrete , 1990 .

[6]  Paolo Cielo,et al.  Pulsed photothermal modeling of layered materials , 1986 .

[7]  Stephanie L. Walkup,et al.  Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures (ACI 440.2R-02) , 2005 .

[8]  Ermanno G. Grinzato,et al.  Statistical analysis of IR thermographic sequences by PCA , 2004 .

[9]  S. Marinetti,et al.  Non Destructive Defect Characterization in Civil Structures Reinforced By Means Of FRP , 2006 .

[10]  S. Marinetti,et al.  Pulse phase infrared thermography , 1996 .

[11]  Zhishen Wu,et al.  Fracturing behaviors of FRP-strengthened concrete structures , 2003 .

[12]  Darryl P Almond,et al.  Defect sizing by transient thermography. I. An analytical treatment , 1994 .

[13]  Scott T Smith,et al.  FRP-strengthened RC beams. I: review of debonding strength models , 2002 .

[14]  Jeff R. Brown,et al.  NDE of fiber-reinforced polymer composites bonded to concrete using IR thermography , 2004, SPIE Defense + Commercial Sensing.

[15]  Kypros Pilakoutas,et al.  Concrete beams with externally bonded flexural FRP-reinforcement: analytical investigation of debonding failure , 2003 .

[16]  Ermanno G. Grinzato,et al.  Some new ideas in dynamic thermal tomography , 1992 .

[17]  Xavier Maldague,et al.  Theory and Practice of Infrared Technology for Nondestructive Testing , 2001 .

[18]  Umberto Galietti,et al.  Non-destructive defect characterization of concrete structures reinforced by means of FRP , 2007 .

[19]  Carlo Pellegrino,et al.  Fiber-Reinforced Polymer Shear Strengthening of Reinforced Concrete Beams: Experimental Study and Analytical Modeling , 2006 .

[20]  Carlo Pellegrino,et al.  Fiber-Reinforced Polymer Shear Strengthening of Reinforced Concrete Beams with Transverse Steel Reinforcement , 2002 .

[21]  S. Marinetti,et al.  Thermal NdE of FRP applied to civil structures , 2006 .

[22]  Kasumassa Nakaba,et al.  BOND BEHAVIOR BETWEEN FIBER-REINFORCED POLYMER LAMINATES AND CONCRETE , 2001 .

[23]  R. C. Mcmaster.  Nondestructive testing handbook , 1959 .

[24]  L. Lorenzis,et al.  Bond of Fiber-Reinforced Polymer Laminates to Concrete , 2001 .

[25]  Claudio Modena,et al.  Experimental Study on Bond Behavior between Concrete and FRP Reinforcement , 2008 .

[26]  Nicholas J. Carino,et al.  Preliminary Thermography Studies for Quality Control of Concrete Structures Strengthened with Fiber-Reinforced Polymer Composites , 2003 .

[27]  D. Marshall,et al.  Review of progress in quantitative non-destructive evaluation: edited by D. O. Thompson and D. E. Chimenti; published by Plenum, New York, 1983; 1853 pp.; price, U.S. $225.00 , 1985 .

[28]  Ermanno G. Grinzato,et al.  Fresco Thermograph IC Inspection by Convective Heating Technique , 1998 .

[29]  H. Kliger,et al.  Effect of Sheet Bonding Condition on Concrete Members Having Externally Bonded Carbon Fiber Sheet , 1996 .