Strengthening and shape modification of fire-damaged concrete with expansive cement concrete and CFRP wrap

Document Type : Article

Authors

1 Department of Civil Engineering, Faculty of Engineering, Eastern Mediterranean University, Famagust, North Cyprus, via Mersin 10 Turkey

2 Department of Civil Engineering, University of Mazandaran, Babolsar, Iran

Abstract

This paper reports the results of an experimental study where the axial capacity of fire-damaged specimens repaired by expansive cement concrete and CFRP wrap were investigated. Specimens were subjected to axial compressive loading and their resulting stress-strain curves were recorded. Since the flat sides of the square samples remained unconfined then the cross sections of the tested specimens largely remained unconfined. The FRP jacket was effective only along the two diagonals of the cross-section. Confinement is generally more effective in specimens with circular cross-section than those with square cross-section. The change in cross section for some of the specimens from square to circle was implemented. To modify the shape, expansive cement concrete has been utilized to fill the gap between the circular and the square cross sections. The test results indicated that heating up to 500 °C caused a severe decline in compressive strength and the elastic modulus of concrete.  Two layers of CFRP wrap around the concrete not only compensated the drop in compressive strength but furthermore it increased the strength beyond that of unheated specimen. However, the effect of wrapping alone on the stiffness and the elastic modulus is negligible. The heated square specimens that were first subjected to shape modification and then wrapped by CFRP sheet, experienced increase in the strength and the elastic modulus. Therefore, the stiffness and the compression strength of fire-damaged square concrete specimens could be compensated fully by the use of shape modification and CFRP wrapping of the cross section.

Keywords

Main Subjects

References

References:
1. Yaqub, M. and Bailey, C.G. "Repair of fire damaged circular reinforced concrete columns with CFRP composites", Construction and Building Materials, 25, pp. 359-370 (2011).
2. Concrete Society Assessment "Design and repair of fire-damaged concrete structures", Technical Report, 68, Camberley, Surrey, UK (2008).
3. Bastami, M., Chaboki-Khiabani, A., Baghbadrani, M., and Kordi, M. "Performance of high strength concretes at elevated temperatures", Scientia Iranica, 18(5), pp. 1028-1036 (2011).
4. Mehta, P.K. and Monteiro, P.J.M., Concrete: Microstructure, Properties, and Materials, McGraw-Hill, New York, NY, USA (2006).
5. Chen, G.M., He, Y.H., Yang, H., Chen, J.F., and Guo, Y.C. "Compressive behavior of steel fiber reinforced recycled aggregate concrete after exposure to elevated temperatures", Construction and Building Materials, 71, pp. 1-15 (2014).
6. Gupta, T., Siddique, S., Sharma, R.K., and Chaudhary, S. "Effect of elevated temperature and cooling regimes on mechanical and durability properties of concrete containing waste rubber fiber", Construction and Building Materials, 137, pp. 35-45 (2017).
7. Huang, Z., Liew, J.Y.R., and Li, W. "Evaluation of compressive behavior of ultra-lightweight cement composite after elevated temperature exposure", Construction and Building Materials, 148, pp. 579-589 (2017).
8. Baradaran-Nasiri, A. and Nematzadeh, M. "The effect of elevated temperatures on the mechanical properties of concrete with fine recycled refractory brick aggregate and aluminate cement", Construction and Building Materials, 147, pp. 865-875 (2017).
9. Xiong, M.X. and Liew, J.Y.R. "Mechanical behaviour of ultra-high strength concrete at elevated temperatures and fire resistance of ultra-high strength concrete filled steel tubes", Materials and Design, 104, pp. 414-427 (2016).
10. Li, L., Jia, P., Dong, J., Shi, L., Zhang, G., and Wang, Q. "Effects of cement dosage and cooling regimes on the compressive strength of concrete after post- fire-curing from 800C", Construction and Building Materials, 142, pp. 208-220 (2017).
11. Xiao, J., Li, Zh., Xie, Q., and Shen, L. "Effect of strain rate on compressive behaviour of high-strength concrete after exposure to elevated temperatures", Fire Safety Journal, 83, pp. 25-37 (2016).
12. Choi, E., Kim, Y.W., Chung, Y.S., and Yang, K.T. "Bond strength of concrete confined by SMA wire jackets", Phys Proc, 10, pp. 210-215 (2010).
13. Choi, E., Chung, Y.S., Kim, Y.W., Kim, J.W. "Monotonic and cyclic bond behavior of confined concrete using NiTiNb SMA Wires", Smart Mater Struct, 20(7), pp. 1-11 (2011).
14. Calderon, P.A., Adam, J.M., Ivorra, S., Pallares, S.F., and Gimenez, E. "Design strength of axially loaded RC columns strengthened by steel caging", Materials & Design, 30(10), pp. 4069-4080 (2009).
15. Turgay, T., Polat, Z., Koksal, H.O., Doran, B., and Karakoc, C. "Compressive behavior of largescale square reinforced concrete columns confined with carbon fiber reinforced polymer jackets", Materials & Design, 31(1), pp. 357-364 (2010).
16. Bisby, L.A., Green, M.F., and Kodur, V.K.R. "Fire endurance of fiber-reinforced polymerconfined concrete columns", ACI Struct. J., 102(6), pp. 883-891 (2005).
17. Chowdhury, E.U., Bisby, L.A., Green, M.F., and Kodur, V.K.R. "Investigation of insulated CFRP wrapped reinforced concrete columns in fire", Fire Safety J., 42(6), pp. 452-460 (2007).
18. Maghsoudi, A.A. and Akbarzadeh Bengar, H. "Acceptable lower bound of the ductility index and serviceability state of RC continuous beams strengthened with CFRP sheets", Scientia Iranica, 18(1), pp. 36-44 (2011).
19. Ghasemi, S., Maghsoudi, A.A., Akbarzadeh Bengar, H., and Ronagh, H.R. "Sagging and hogging strengthening of continuous unbonded posttensioned HSC beams by NSM and EBR", J. Compos. Constr, 20(2), pp. 1-13 (2016).
20. Balaguru, P., Nanni, A., and Giancaspro, J., CFRP Composites for Reinforced and Prestressed Concrete Structures, Taylor and Francis, New York (2009).
21. Yan, Z. "Shape modification of rectangular columns confined with CFRP composites", PhD Thesis, Salt Lake City (UT), Dept. Civil and Environmental Eng., University of Utah (2005).
22. Behzard, P., Sharbatdar, M.K., and Kheyroddin, A. "Different NSM CFRP technique for strengthening of RC two-way slabs with low clear cover thickness", Scientia Iranica, 23(2), pp. 520-534 (2016).
23. Shin, J., Scott, D.W., Stewart, L.K., Yang, Ch., Wright, T.R., and Roches, R.D. "Dynamic response of a full-scale reinforced concrete building frame retrofitted with CFRP column jackets", Engineering Structures, 125, pp. 244-253 (2016).
24. Hadi, M.N.S. "Behaviour of eccentric loading of CFRP confined fibre steel reinforced concrete columns", Constr Build Mater, 23(2), pp. 1102-1108 (2009).
25. Parvin, A., Altay, S., Yalcin, C., and Kaya, O. "CFRP rehabilitation of concrete frame joints with inadequate shear and anchorage details", J. Compos Constr, 14(1), pp. 72-82 (2010).
26. Teng, J.G., Chen, J.F., Smith, S.T., and Lam, L., CFRP Strengthened RC Structures, Wiley Chichester (2002).
27. Debaiky, S.A. Green, M.F., and Hope, B.B. "Carbon fibre-reinforced polymer wraps for corrosion control and rehabilitation of reinforced concrete columns", ACI Mater J., 99(2), pp. 129-137 (2002).
28. Ilia, E., Mostofinejad, D., and Moghaddas, A. "Performance of corner strips in CFRP confinement of rectilinear RC columns", Scientia Iranica, 22(6), pp. 2024-2032 (2015).
29. Issa, M.A., and Rajai, Z.A. "Experimental and parametric study of circular short columns confined with CFRP composites", J. Compos Constr, 13(2), pp. 135- 147 (2009).
30. Maaddawy, T. "Post-repair performance of eccentrically loaded RC columns wrapped with CFRP composites", Cement Concr Compos, 30(9), pp. 822-830 (2008).
31. Toutanji, H., Han, M., Gilbert, J., and Matthys, S. "Behaviour of large scale rectangular columns confined with CFRP composites", J. Compos Constr, (ASCE), 29, pp. 62-71 (2009).
32. Chowdhury, E.U., Bisby, L.A., Green, M.F., and Kodur, V.K.R. "Residual behaviour of fire exposed reinforced concrete beams prestrengthened in flexure with fibre reinforced polymer sheets", J. Compos Constr, 12(1), pp. 44-52 (2008).
33. Haddad, R.H., Shannag, M.J., and Hamad, R.J. "Repair of heat damaged reinforced concrete T-beams using FRC jackets", J. Mag. Concr. Res., 59(3), pp. 223-231 (2007).
34. Yan, Z. and Zhisheng, X.U., Experimental Study on Safety Test for Reinforced Concrete Columns Strengthened with Carbon Fibre Reinforced Polymers After Fire, Disaster Prevention Science and Safety Technology Institute, Central South University, Changsha, China (2005).
35. Zhong, T. and Lin-Hai, H. "Behaviour of fire-exposed concrete-filled steel tubular beam columns repaired with CFRP wraps", J. Thin-walled Struct, 45(1), pp. 63-76 (2007).
36. Zhong, T., Lin-Hai, H., and Ling-Ling, W. "Compressive and  flexural behavior of CFRP-repaired concrete- filled steel tubes after exposure to fire", J. Constr Steel Res, 63(8), pp. 1116-1126 (2007).
37. Karbhari, V.M. and Gao, Y. "Composite jacketed concrete under uniaxial compression verification of simple design equations", J. Mater Civil Eng., ASCE, 9(4), pp. 185-193 (1997).
38. Rochette, P. and Labossiere, P. "Axial testing of rectangular column models confined with composites", J. Compos Constr ASCE, 4(3), pp. 129-136 (2000).
39. Maaddawy, T.E., Sayed, M.E., and Abdel-Magid, B. "The effects of cross-sectional shape and loading condition on performance of reinforced concrete members confined with carbon fiber-reinforced polymers", Materials & Design, 31, pp. 2330-2341 (2010).
40. Yan, Z. and Pantelides, C.P. "Concrete column shape modification with FRP shells and expansive cement concrete", Construction and Building Materials, 25, pp. 396-405 (2011).
41. Ma, Ch., Apandi, N., Yung, S., Hau, Ng., Haur, L., Awang, A., and Omar, W. "Repair and rehabilitation of concrete structures using confinement: A review", Construction and Building Materials, 133, pp. 502-515 (2017).
42. Shin, J., Scott, D.W., Stewart, L.K., Yang, C.S., and DesRoches, R. "Dynamic response of a full-scale reinforced concrete building frame retrofitted with FRP column jackets", Engineering Structures, 125, pp. 244-253 (2016).
43. Molhotra, H.L. "The effect of temperature on the compressive strength of concrete", Mag. Concr. Res, 8(22), pp. 85-94 (1956).
44. Wu, B., Ma, Z.C., and Ou, J.P. "Experimental research on deformation and constitutive relationship of concrete under axial loading and high temperature", J. Build. Struct, 20(5), pp. 42-49 (1999).
45. Chang, Y.F., Chen, Y.H., Sheu, M.S., and Yao, G.C. "Residual stress strain relationship for concrete after exposure to high temperatures", Cement and Concrete Research, 36, pp. 1999-2005 (2006).
46. The Concrete Society, "Repair of concrete structures with reference to BS EN 1504", Technical Report No. 69 (2009).
Scientia Iranica
Volume 26, Issue 2 - Serial Number 2
Transactions on Civil Engineering (A)
March and April 2019
Pages 699-708

Files

History

  • Receive Date: 18 March 2017
  • Revise Date: 26 June 2017
  • Accept Date: 13 November 2017

Share

How to cite

Statistics