Experimental Study on Full-scale Girders Strengthened with Prestressed NSM Tendons

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Title: Experimental Study on Full-scale Girders Strengthened with Prestressed NSM Tendons

Author(s): Woo-tai Jung, Jong-sup Park, Jae-yoon Kang, and Hee beom Park

Publication: Symposium Paper

Volume: 327

Issue:

Appears on pages(s): 16.1-16.16

Keywords: carbon fiber reinforced polymer (CFRP), girder, near surface mounted (NSM), prestressed, strengthened

DOI: 10.14359/51713337

Date: 11/1/2018

Abstract:
Various techniques have been developed and applied to strengthen deteriorated RC (Reinforced Concrete) structures such as the EBR (Externally Bonded Reinforcements) and NSM (Near Surface Mounted) systems. However, NSM still suffers premature failure like EBR. Recent research tried to prestress the NSM but the prestressed NSM needs a special prestressing system. Accordingly, this study develops a new prestressing system for NSM using CFRP tendons. The field-applicability of the developed prestressing system is evaluated through an application on a full-scale PC girder of 20 m with the objective of improving the girder’s performance by 30%. The girder is strengthened using 5 NSM CFRP tendons with the introduction of a prestressing force of 100 kN in each of them. The test results demonstrated the applicability of the new prestressing system since the flexural capacity of the girder was successfully increased by 30%.

Related References:

1. Rezazadeh, M., Ramezansefat, H., and Barros, J., 2016, “NSM CFRP Prestressing Techniques with Strengthening Potential for Simultaneously Enhancing Load Capacity and Ductility Performance”, Journal of Composites for Construction, vol. 20, no. 5.

2. Jung, W.T., Park, J.S., and Park, Y.H., 2009, “An Experimental Study on Application of New Prestressing System for NSM Strengthening Technique”, Proceedings of the 9th International Symposium on Fiber Reinforced Polymer Reinforcement for Reinforced Concrete Structures (FRPRCS-9).

3. Nordin, H. and Täljsten, B., 2006, "Concrete Beams Strengthened with Prestressed Near Surface Mounted CFRP", Journal of Composite for Construction, Vol. 10, No. 1, pp. 60-68.

4. Badawi, M. A., 2007, "Monotonic and Fatigue Flexural Behaviour of RC Beams Strengthened with Prestressed NSM CFRP Rods", A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Doctor of Philosophy in Civil Engineering, Waterloo, Ontario, Canada.

5. El-Hacha, R. and Soudki, K., 2013, “Prestressed near-surface mounted fibre reinforced polymer reinforcement for concrete structures–a review.” Can. J. Civ. Eng., 40(11), 1127–1139.

6. Ministry of Land, Infrastructure and Transport, 2013, “Yearbook of Road Statistics”

7. Jung, W.T., Park, Y.H., Park, J.S., and Kim, C.Y., 2011, “Strengthening effect of reinforced concrete beams strengthened with NSM CFRP reinforcements and various reinforcement details”, Journal of the Korea Concrete Institute, Vol. 23, No. 6, 2011, pp. 781-790.

8. Park, Y.H., Park, J.S., Jung, W.T., and You, Y.J., 2006, “Development of strengthening methods for deteriorated concrete bridges”, Internal research project KICT 2006-082, Korea Institute of Construction Technology.

9. De-Lorenzis, L., Micelli, F., and La Tagola, A., 2002, "Passive and active near-surface mounted FRP rods for flexural strengthening of RC concrete beams", In Proceedings of the 3rd International Conference on Composites in Infrastructure, San Francisco, USA, CD-ROM.

10. Jung, W.T., Kang, J.Y., Park, J.S., Park, Y.H., Keum, M.S., Kang, S.H., Kim, D.Y., Pyun, S.B., and Kwon, H.C., 2015, “Development of bridge strengthening method using prestressed FRP composites”, Internal research project KICT 2015-089, Korea Institute of Construction Technology.

11. Jung, W.T., Park, Y.H., and Park, J.S., 2011, “An experimental study on improving anchor performance for CFRP tendons”, Proceeding of the 10th international conference on fiber reinforced polymer reinforcement for concrete structures (FRPRCS-10).