Browse > Article
http://dx.doi.org/10.4334/JKCI.2016.28.5.535

Combined Effects of Sustained Load and Temperature on Pull-off Strength and Creep Response between CFRP Sheet and Concrete Using Digital Image Processing  

Jeong, Yo-Seok (Research Institute for Construction Disaster Prevention, Chungnam National University)
Lee, Jae-Ha (Dept. of Civil Engineering, Korea Maritime and Ocean University)
Kim, Woo-Seok (Dept. of Civil Engineering, Chungnam National University)
Publication Information
Journal of the Korea Concrete Institute / v.28, no.5, 2016 , pp. 535-544 More about this Journal
Abstract
This paper aims at examining the effects of sustained load and elevated temperature on the time-dependent deformation of a carbon fiber reinforced polymer (CFRP) sheets bonded to concrete as well as the pull-off strength of single-lap shear specimens after the sustained loading period using digital images. Elevated temperature during the sustained loading period resulted in increased slip of the CFRP composites, whereas increased curing time of the polymer resin prior to the sustained loading period resulted in reduced slip. Pull-off tests conducted after sustained loading period showed that the presence of sustained load resulted in increased pull-off strength and interfacial fracture energy. This beneficial effect decreased with increased creep duration. Based on analysis of digital images, results on strain distributions and fracture surfaces indicated that stress relaxation of the epoxy occurred in the 30 mm closest to the loaded end of the CFRP composites during sustained loading, which increased the pull-off strength provided the failure locus remained mostly in the concrete. For longer sustained loading duration, the failure mode of concrete-CFRP bond region can change from a cohesive failure in the concrete to an interfacial failure along the concrete/epoxy interface, which diminished part of the strength increase due to the stress relaxation of the adhesive.
Keywords
digital image processing; fiber reinforced polymer; pull-off testing; sustained load; temperature;
Citations & Related Records
Times Cited By KSCI : 6  (Citation Analysis)
연도 인용수 순위
1 ACI 440.2R-08, "Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures", ACI, 2008.
2 Park, J., Jung, W., You, Y., and Park, Y., "An Estimate of Flexural Strength for Reinforce Concrete Beams Strengthened with CFRP Sheets", Journal of the Korea Concrete Institute, Vol.17, No.2, 2005, pp.213-220.   DOI
3 Sim, J., Oh, H., Moon, D., and Park, K., "Prediction of the Shear Strength of FRP Strengthened RC Beams (I)-Development and Evaluation of Shear strength model", Journal of the Korea Concrete Institute, Vol.17, No.3, 2005, pp.343-351.   DOI
4 You, Y., Choi, K., and Kim, K., "An Experimental Study to Prevent Debonding Failure of RC Beams Strengthened with GFRP Sheets", Journal of the Korea Concrete Institute, Vol.19, No.6, 2007, pp.677-684.   DOI
5 Chen, J., and Teng, J., "Anchorage strength models for FRP and steel plates bonded to concrete", Journal of Structural Engineering, Vol.127, No.7, 2001, pp.784-791.   DOI
6 Toutanji, H., Saxena, P., Zhao, L., and Ooi, T., "Prediction of Interfacial Bond Failure of FRP-concrete Surface", Journal of Composites for Construction, Vol.11, No.4, 2007, pp.427-436   DOI
7 Ouyang, Z., and Wan, B., "Experimental and Numerical Study of Moisture Rffects on the Bond Fracture Energy of FRP/Concrete Joints", Journal Reinforced Plastics and Composites, Vol.27, No.2, 2008, pp.205-223.   DOI
8 Tuakta, C., and Buyukozturk, O., "Deterioration of FRP/ Concrete Bond System Under Variable Moisture Conditions Quantified by Fracture Mechanics", Composites Part B: Engineering, Vol.42, No.2, 2011, pp.145-154.   DOI
9 Biscaia, H., Silva, M., and Chastre, C., "An Experimental Study of GFRP-to-concrete Interfaces Submitted to Humidity Cycles", Composite Structures, Vol.10, No.1, 2014, pp. 354-368.
10 Hong, H., and Shin, Y., "Structural Performance Evaluation of Reinforced Concrete Beams with Externally Bonded FRP Sheets", Journal of the Korea Concrete Institute, Vol.15, No.1, 2003, pp.78-86.   DOI
11 Gullapalli, A., Lee, J., Lopez, M., and Bakis, C., "Sustained Loading and Temperature Response of Fiber-reinforced Polymer-concrete Bond", Transportation Research Record, Vol.2131, 2009, pp.155-162.   DOI
12 Tartar, J., and Hamilton, H., "Bond Durability Factor for Externally Bonded CFRP Systems in Concrete", Journal of Composites for Construction, Vol.20, No.1, 2016.
13 Kim, S., Kim, K., Han, K., Song, S., and Park, S., "A Prediction of the Long-Term Deflection of RC Beams Externally Bonded with CFRP and GFRP", Journal of the Korea Concrete Institute, Vol.20, No.6, 2008, pp.765-771.   DOI
14 You, Y., Choi, K., and Kim, K., "Long-Term Behavior of CFRP Strips under Sustained Loads", Journal of the Korea Concrete Institute, Vol.21, No.2, 2009, pp.139-146.   DOI
15 Jia, J., Boothby, T., Bakis, C., and Brown, T., "Durability Evaluation of Glass Fiber Reinforced-polymer-concrete Bonded Interfaces", Journal of Composites for Construction, Vol.9, No.4, 2005, pp.348-359.   DOI
16 Diab, H., and Wu, Z., "Nonlinear Constitutive Model for Time-dependent Behavior of FRP-concrete Interface", Composites Science and Technology, Vol.67, No.11-12, 2007, pp.2323-2333.   DOI
17 Ferrier, E., Michel, L., Jurkiewiez, B., and Hamelin, P., "Creep Behavior of Adhesives used for External FRP Strengthening of RC Structures", Construction and Building Materials, Vol.25, No.2, 2011, pp.461-467.   DOI
18 Hamed, E., and Bradford, M., "Flexural Time-dependent Cracking and Post-cracking Behaviour of FRP Strengthened Concrete Beams", International Journal of Solids and Structures, Vol.49, No.13, 2012, pp.1595-1607.   DOI
19 Zhang, C., and Wang, J., "Interface Stress Redistribution in FRP-strengthened Reinforced Concrete Beams Using a Three-parameter Viscoelastic Foundation Model", Composites Part B: Engineering, Vol.43, No.9, 2012, pp.3009-3019.   DOI
20 Jaipuriar, A., Characterization and modeling of creep behavior in ambient temperature cured thermoset resin, Master's dissertation, Pennsylvania State University, 2011.
21 Jaipuriar, A., Bakis, C., and Lopez, M.. "Cure Kinetics and Physical Aging of an Ambient-curing Epoxy Resin". In Proc. of the 6th Intl. Conf on Composite FRP in Civil Engineering 2012, CICE 2012, Rome, Italy.
22 Peters, W., and Ranson, W., "Digital Imaging Techniques in Experimental Stress Analysis", Optical Engineering, Vol.21, No.3, 1982, pp.427-431.
23 Lee, J., and Lopez, M.. "Non-contact measuring techniques to characterize deformation on FRP Uwrap anchors", Proc. 10th International Symposium on Fiber-Reinforced Polymer Reinforcement for Concrete Structures 2011, FRPRCS-10, ACI, Tampa, FL, United States, pp.245-258.
24 Jeong, Y., Effects of temperature and sustained loading on the response of FRP-strengthened concrete elements, Doctoral Thesis, Pennsylvania State University, U.S., 2014.
25 Ruocci, G., Argoul, P., Benzarti, K., and Freddi, F., "An Improved Damage Modelling To Deal With The Variability Of Fracture Mechanisms In FRP Reinforced Concrete Structures", International Journal of Adhesion and Adhesives, Vol.45, 2013, pp.7-20.   DOI
26 Mazzotti, C., and Savoia, M., "Stress Redistribution Along the Interface Between Concrete and FRP Subject to Longterm Loading", Advances in Structural Engineering, Vol.12, No.5, 2009, pp.651-661.   DOI
27 Dai, J., Ueda, T., and Sato, Y., "Development of the Nonlinear Bond Stress-Slip Model of Fiber Reinforced Plastics Sheet-concrete Interfaces With a Simple Method", Journal of Composites for Construction, Vol.9, No.1, 2005, pp.52-62.   DOI
28 Dai, J., Gao, W., and Teng, J., "Bond-slip Model for FRP Laminates Externally Bonded to Concrete at Elevated Temperature", Journal of Composites for Construction, Vol.17, No.2, 2013, pp.217-228.   DOI