Advance repairing technique for enhancement of stiffness of post-heated concrete cylinders
Tóm tắt
The present study investigates the effectiveness of epoxy injection on the performance of post-heated concrete cylinders confined with carbon fiber-reinforced polymer composites (CFRP). A total of 42 standard dimensions (diameter of 150 mm × 300 mm) were tested under uniaxial compression. These cylinders were divided into two groups regarding the heating, i.e., un-heated and post-heated. Furthermore, the post-heated concrete specimens were further divided into four specimen groups with respect to various temperatures, i.e., 400 °C, 600 °C, 700 °C, and 800 °C, and then cooled to room temperature. The axial compressive behavior of un-heated unconfined (UHUC), un-heated CFRP confined (UHC), post-heated unconfined (PHUC), post-heated CFRP confined (PHC), and epoxy-injected post-heated CFRP confined concrete cylinders (PHEC) were investigated in terms of axial compressive strength (fc′), stiffness (k), energy dissipation capacity (EDC), and restorability. The test results showed that CFRP confinement significantly enhances the fc′ and EDC of the PHC subjected to the mentioned temperatures. Furthermore, the CFRP confinement effectiveness was increased with increasing the level of fire damage (i.e., at a higher temperature). It was found that the fc′ of PHEC at 400 °C was restored up to the design value of UHUC. However, the PHEC was unsuccessful in restoring the design value for temperatures higher than 400 °C.
Tài liệu tham khảo
Al-Nimry, H. S., & Ghanem, A. M. (2017). FRP confinement of heat-damaged circular RC columns. International Journal of Concrete Structures Materials, 11, 115–133.
Al-Nimry, H., Haddad, R., Afram, S., & Abdel-Halim, M. (2013). Effectiveness of advanced composites in repairing heat-damaged RC columns. Materials & Structures, 46, 1843–1860.
Al-Nimry, H., & Jawarneh, M. (2017). Effects of increased slenderness in short heat-damaged RC columns confined with FRP composites. Materials & Structures, 50, 95.
Bailey, C., & Yaqub, M. (2012). Seismic strengthening of shear critical post-heated circular concrete columns wrapped with FRP composite jackets. Composite Structures, 94, 851–864.
Bisby, L., Chen, J., Li, S., Stratford, T., Cueva, N., & Crossling, K. (2011). Strengthening fire-damaged concrete by confinement with fibre-reinforced polymer wraps. Engineering Structures, 33, 3381–3391.
Chaallal, O., Shahawy, M., & Hassan, M. (2003). Performance of axially loaded short rectangular columns strengthened with carbon fiber-reinforced polymer wrapping. Journal of Composites for Construction, 7, 200–208.
Chen, Y.-H., Chang, Y.-F., Yao, G. C., & Sheu, M.-S. (2009). Experimental research on post-fire behaviour of reinforced concrete columns. Fire Safety Journal, 44, 741–748.
Duff, R. A. 1976. Reinforced concrete construction. Google Patents.
Fakharifar, M., & Chen, G. (2016). Compressive behavior of FRP-confined concrete-filled PVC tubular columns. Composite Structures, 141, 91–109.
Guo, Y., Xie, J., Xie, Z., & Zhong, J. (2016). Experimental study on compressive behavior of damaged normal-and high-strength concrete confined with CFRP laminates. Construction Building Materials, 107, 411–425.
Hassan, W., Hodhod, O., Hilal, M., & Bahnasaway, H. (2017). Behavior of eccentrically loaded high strength concrete columns jacketed with FRP laminates. Construction Building Materials, 138, 508–527.
Issa, M. A., Alrousan, R. Z., & Issa, M. A. (2009). Experimental and parametric study of circular short columns confined with CFRP composites. Journal of Composites for Construction, 13, 135–147.
Karam, E. C., Hawileh, R. A., el Maaddawy, T., & Abdalla, J. A. (2017). Experimental investigations of repair of pre-damaged steel-concrete composite beams using CFRP laminates and mechanical anchors. Thin-Walled Structures, 112, 107–117.
Kim, Y. J., & Ji, Y. (2017). Axial load-bearing concrete confined with carbon fiber-reinforced polymer sheets in acidic environment. ACI Structural Journal, 114, 775.
Lenwari, A., Rungamornrat, J., & Woonprasert, S. (2016). Axial compression behavior of fire-damaged concrete cylinders confined with CFRP sheets. Journal of Composites for Construction, 20, 04016027.
Ma, C.-K., Apandi, N. M., Sofrie, C. S. Y., Ng, J. H., Lo, W. H., Awang, A. Z., & Omar, W. (2017). Repair and rehabilitation of concrete structures using confinement: A review. Construction Building and Materials, 133, 502–515.
Pino, V., Nanni, A., Arboleda, D., Roberts-Wollmann, C., & Cousins, T. (2016). Repair of damaged prestressed concrete girders with FRP and FRCM composites. Journal of Composites for Construction, 21, 04016111.
Roy, A., Sharma, U., & Bhargava, P. (2014). Strengthening of heat damaged reinforced concrete short columns. Journal of Structural Fire Engineering, 5, 381–398.
Roy, A. B. D., Sharma, U. K., & Bhargava, P. (2015). Confinement strengthening of heat-damaged reinforced concrete columns. Magazine of Concrete Research, 68, 291–304.
Saljoughian, A., & Mostofinejad, D. (2017). Rectangular reinforced concrete columns strengthened with carbon fiber-reinforced polymer sheets using corner strip-batten method. ACI Structural Journal, 114, 659.
Vogel, H., Davoudi, S., Noël, M., Svecova, D. & Stdt, U. Evaluation of properties of high strength concrete for prestressed concrete prisms. In Proceedings of the second international symposium on ultra high performance concrete, 2008. 287–294.
Yaqub, M., & Bailey, C. (2011a). Cross sectional shape effects on the performance of post-heated reinforced concrete columns wrapped with FRP composites. Composite Structures, 93, 1103–1117.
Yaqub, M., & Bailey, C. (2011b). Repair of fire damaged circular reinforced concrete columns with FRP composites. Construction Building and Materials, 25, 359–370.
Yaqub, M., & Bailey, C. (2012). Seismic performance of shear critical post-heated reinforced concrete square columns wrapped with FRP composites. Construction Building Materials, 34, 457–469.
Yaqub, M., Bailey, C., & Nedwell, P. (2011). Axial capacity of post-heated square columns wrapped with FRP composites. Cement Concrete Composites, 33, 694–701.
Yaqub, M., Bailey, C., Nedwell, P., Khan, Q., & Javed, I. (2013). Strength and stiffness of post-heated columns repaired with ferrocement and fibre reinforced polymer jackets. Composites Part B: Engineering, 44, 200–211.