Title:
Soffit and U-Wrap Fabric-Reinforced Cementitious Matrix Strengthening for Reinforced Concrete Beams
Author(s):
Usama Ebead, Ahmed El Refai, Kshitij Shrestha, and Antonio Nanni
Publication:
Structural Journal
Volume:
116
Issue:
2
Appears on pages(s):
267-278
Keywords:
cementitious materials; composites; ductility; fabric-reinforced cementitious matrix; flexure; repair; strengthening
DOI:
10.14359/51713292
Date:
3/1/2019
Abstract:
The structural performance of reinforced concrete (RC) beams strengthened with fabric-reinforced cementitious matrix (FRCM) was investigated. Fourteen unstrengthened and strengthened beams were tested in flexure under four-point load configuration. Test parameters included the internal reinforcement ratios (0.5% representing flexure-deficient beams and 0.72 or 1.27% representing typical under-reinforced beams), the type of FRCM fabric (carbon and polyparaphenylene benzobisoxazole [PBO]), the number of fabric plies (one and two plies), and the strengthening scheme (straight at soffit or U-wrap). Test results revealed that the gain in flexural strength was inversely proportional to the internal reinforcement ratio of the beams regardless of the fabric type, scheme, or number of plies used. U-wrap strengthening scheme provided an inherent anchorage that limited the premature delamination of the fabric, which was a common mode of failure in the soffit-strengthening scheme. Beams strengthened with U-wrap single-ply of carbon- and PBO-FRCM showed an average gain in strength of 70% and 51%, respectively, compared to 28% and 20% for their counterparts strengthened with the soffit scheme. Moreover, the use of U-wrap double-ply of PBO fabric resulted in an average gain in strength of 72%. The theoretical formulations of ACI 549 satisfactorily predicted the load-carrying capacities of the soffit and U-wrap strengthened beams with an average ratio of Pu/Pu Th of 1.07 and a standard deviation of 11%.
Related References:
1. Tajaddini, A.; Ibell, T.; Darby, A.; Evernden, M.; and Silva, P., “Effect of Fiber-Reinforced Polymer Strengthening on Moment Redistribution in Reinforced Concrete Members,” ACI Structural Journal, V. 115, No. 4, July 2018, pp. 907-916. doi: 10.14359/51702041
2. Garcia, J. E.; Satrom, C. N.; Jirsa, J. O.; and Ghannoum, W. M., “Shear Strengthening of Concrete Girders Using Carbon Fiber-Reinforced Polymer Sheets and Anchors,” ACI Structural Journal, V. 115, No. 4, July 2018, pp. 1165-1173. doi: 10.14359/51702234
3. Ebead, U., and Marzouk, H., “Strengthening of Two-Way Slabs Subjected to Moment and Cyclic Loading,” ACI Structural Journal, V. 99, No. 4, July-Aug. 2002, pp. 435-444.
4. Kim, Y. J.; Kang, J.-Y.; Park, J.-S.; and Jung, W.-T., “Prestress Loss of Post-Tensioned Near-Surface-Mounted Carbon Fiber-Reinforced Polymer for Bridge Strengthening,” ACI Structural Journal, V. 115, No. 5, Sept. 2018, pp. 1496-1506. doi: 10.14359/51702446
5. Kaish, A. B. M. A.; Jamil, M.; Raman, S. N.; Zain, M. F. M.; and Nahar, L., “Ferrocement Composites for Strengthening of Concrete Columns: A Review,” Construction and Building Materials, V. 160, 2018, pp. 326-340. doi: 10.1016/j.conbuildmat.2017.11.054
6. Ebead, U., “Inexpensive Strengthening Technique for Partially Loaded Reinforced Concrete Beams : Experimental Study,” Journal of Materials in Civil Engineering, ASCE, V. 27, No. 10, 2015, pp. 1-11. doi: 10.1061/(ASCE)MT.1943-5533.0001249
7. Takiguchi, K., “Shear Strengthening of Reinforced Concrete Columns Using Ferrocement Jacket,” ACI Structural Journal, V. 98, No. 5, Sept.-Oct. 2001, pp. 696-704.
8. Li, B.; Lam, E. S.-S.; Wu, B.; and Wang, Y., “Effect of High Axial Load on Seismic Behavior of Reinforced Concrete Beam-Column Joints with and without Strengthening,” ACI Structural Journal, V. 112, No. 6, Nov.-Dec. 2015, pp. 713-723. doi: 10.14359/51687938
9. Tetta, Z.; Koutas, L.; and Bournas, D., “Textile-Reinforced Mortar (TRM) versus Fiber-Reinforced Polymers (FRP) in Shear Strengthening of Concrete Beams,” Composites. Part B, Engineering, V. 77, Apr., 2015, pp. 338-348. doi: 10.1016/j.compositesb.2015.03.055
10. Tetta, Z. C.; Koutas, L. N.; and Bournas, D., “Shear Strengthening of Full-Scale RC T-Beams Using Textile-Reinforced Mortar and Textile-Based Anchors,” Composites. Part B, Engineering, V. 95, 2016, pp. 225-239. doi: 10.1016/j.compositesb.2016.03.076
11. D’Ambrisi, A.; Feo, L.; and Focacci, F., “Experimental Analysis on Bond between PBO-FRCM Strengthening Materials and Concrete,” Composites. Part B, Engineering, V. 44, No. 1, 2013, pp. 524-532. doi: 10.1016/j.compositesb.2012.03.011
12. Ombres, L., “Structural Performances of Reinforced Concrete Beams Strengthened in Shear with a Cement Based Fiber Composite Material,” Composite Structures, V. 122, 2015, pp. 316-329. doi: 10.1016/j.compstruct.2014.11.059
13. Elghazy, M.; El Refai, A.; Ebead, U.; and Nanni, A., “Fatigue and Monotonic Behaviors of Corrosion-Damaged Reinforced Concrete Beams Strengthened with FRCM Composites,” Journal of Composites for Construction, ASCE, V. 22, No. 5, 2018, p. 04018040 doi: 10.1061/(ASCE)CC.1943-5614.0000875
14. Shrestha, K. C.; Ebead, U.; and Younis, A., “Effect of Surface Roughening on Concrete/TRM Bond,” ISEC 2017 – 9th International Structural Engineering and Construction Conference: Resilient Structures and Sustainable Construction, Valencia, Spain, 2017, 6 pp.
15. Tran, C. T. M.; Stitmannaithum, B.; and Ueda, T., “Investigation of The Bond Behaviour Between PBO-FRCM Strengthening Material and Concrete,” Journal of Advanced Concrete Technology, V. 12, No. 12, 2014, pp. 545-557. doi: 10.3151/jact.12.545
16. D’Antino, T.; Sneed, L. H.; Carloni, C.; and Pellegrino, C., “Influence of the Substrate Characteristics on the Bond Behavior of PBO FRCM-Concrete Joints,” Construction and Building Materials, V. 101, 2015, pp. 838-850. doi: 10.1016/j.conbuildmat.2015.10.045
17. Bencardino, F., and Condello, A., “Eco-Friendly External Strengthening System for Existing Reinforced Concrete Beams,” Composites. Part B, Engineering, V. 93, 2016, pp. 163-173. doi: 10.1016/j.compositesb.2016.03.022
18. Elghazy, M.; El Refai, A.; Ebead, U.; and Nanni, A., “Corrosion-Damaged RC Beams Repaired with Fabric-Reinforced Cementitious Matrix,” Journal of Composites for Construction, ASCE, V. 22, No. 5, 2018, p. 04018039 doi: 10.1061/(ASCE)CC.1943-5614.0000873
19. International Code Council, “Acceptance Criteria for Masonry and Concrete Strengthening Using Fabric-Reinforced Cementitious Matrix (FRCM) Composite Systems (AC434),” Washington, DC, 2013, 19 pp.
20. ACI Committee 549, “Guide to Design and Construction of Externally Bonded Fabric-Reinforced Cementitious Matrix (FRCM) Systems for Repair and Strengthening Concrete and Masonry Stuctures (ACI 549.4R-13),” American Concrete Institute, Farmington Hills, MI, 2013, 69 pp.
21. Sneed, L. H.; D’Antino, T.; Carloni, C.; and Pellegrino, C., “A Comparison of the Bond Behavior of PBO-FRCM Composites Determined by Double-Lap and Single-Lap Shear Tests,” Cement and Concrete Composites, V. 64, 2015, pp. 37-48. doi: 10.1016/j.cemconcomp.2015.07.007
22. Carozzi, F. G., and Poggi, C., “Mechanical Properties and Debonding Strength of Fabric Reinforced Cementitious Matrix (FRCM) Systems for Masonry Strengthening,” Composites. Part B, Engineering, V. 70, 2015, pp. 215-230. doi: 10.1016/j.compositesb.2014.10.056
23. Younis, A., and Ebead, U., “Bond Characteristics of Different FRCM Systems,” Construction and Building Materials, V. 175, 2018, pp. 610-620. doi: 10.1016/j.conbuildmat.2018.04.216
24. Raoof, S. M.; Koutas, L. N.; and Bournas, D., “Bond between Textile-Reinforced Mortar (TRM) and Concrete Substrates: Experimental Investigation,” Composites. Part B, Engineering, V. 98, 2016, pp. 350-361. doi: 10.1016/j.compositesb.2016.05.041
25. Hashemi, S., and Al-Mahaidi, R., “Investigation of Bond Strength and Flexural Behaviour of FRP-Strengthened Reinforced Concrete Beams Using Cement-Based Adhesives,” Australian Journal of Structural Engineering, V. 11, No. 2, 2010, pp. 129-139. doi: 10.1080/13287982.2010.11465061
26. Carloni, C.; D’Antino, T.; Sneed, L.; and Pellegrino, C., “Role of the Matrix Layers in the Stress-Transfer Mechanism of FRCM Composites Bonded to a Concrete Substrate,” Journal of Engineering Mechanics, ASCE, V. 141, No. 6, 2015, p. 04014165 doi: 10.1061/(ASCE)EM.1943-7889.0000883
27. Loreto, G.; Leardini, L.; Arboleda, D.; and Nanni, A., “Performance of RC Slab-Type Elements Strengthened with Fabric-Reinforced Cementitious-Matrix Composites,” Journal of Composites for Construction, ASCE, V. 18, No. 3, 2014, p. A4013003 doi: 10.1061/(ASCE)CC.1943-5614.0000415
28. Brückner, A.; Ortlepp, R.; and Curbach, M., “Textile Reinforced Concrete for Strengthening in Bending and Shear,” Materials and Structures, V. 39, No. 8, 2006, pp. 741-748. doi: 10.1617/s11527-005-9027-2
29. Bournas, D.; Lontou, P. V.; Papanicolaou, C. G.; and Triantafillou, T. C., “Textile-Reinforced Mortar versus Fiber-Reinforced Polymer Confinement in Reinforced Concrete Columns,” ACI Structural Journal, V. 104, No. 6, Nov.-Dec. 2007, pp. 740-748. doi: 10.14359/18956
30. Trapko, T., “Confined Concrete Elements with PBO-FRCM Composites,” Construction and Building Materials, V. 73, 2014, pp. 332-338. doi: 10.1016/j.conbuildmat.2014.09.055
31. Ombres, L., and Verre, S., “Structural Behaviour of Fabric Reinforced Cementitious Matrix (FRCM) Strengthened Concrete Columns under Eccentric Loading,” Composites. Part B, Engineering, V. 75, 2015, pp. 235-249. doi: 10.1016/j.compositesb.2015.01.042
32. Ombres, L., “Flexural Analysis of Reinforced Concrete Beams Strengthened with a Cement Based High Strength Composite Material,” Composite Structures, V. 94, No. 1, 2011, pp. 143-155. doi: 10.1016/j.compstruct.2011.07.008
33. Pellegrino, C., and D’Antino, T., “Experimental Behaviour of Existing Precast Prestressed Reinforced Concrete Elements Strengthened with Cementitious Composites,” Composites. Part B, Engineering, V. 55, 2013, pp. 31-40. doi: 10.1016/j.compositesb.2013.05.053
34. Elsanadedy, H. M.; Almusallam, T. H.; Alsayed, S.; and Al-Salloum, Y., “Flexural Strengthening of RC Beams Using Textile Reinforced Mortar —Experimental and Numerical Study,” Composite Structures, V. 97, 2013, pp. 40-55. doi: 10.1016/j.compstruct.2012.09.053
35. Arboleda, D.; Babaeidarabad, S.; and Nanni, A., “Durability of Fabric Reinforced Cementitious Matrix (FRCM) Composites,” 7th International Conference of FRP Composites in Civil Engineering, International Institute for FRP in Construction, Vancouver, BC, Canada, 2014, pp. 1-6.
36. Escrig, C.; Gil, L.; and Bernat-Maso, E., “Experimental Comparison of Reinforced Concrete Beams Strengthened against Bending with Different Types of Cementitious-Matrix Composite Materials,” Construction and Building Materials, V. 137, 2017, pp. 317-329. doi: 10.1016/j.conbuildmat.2017.01.106
37. Younis, A.; Ebead, U.; and Shrestha, K. C., “Different FRCM Systems for Shear-Strengthening of Reinforced Concrete Beams,” Construction and Building Materials, V. 153, 2017, pp. 514-526. doi: 10.1016/j.conbuildmat.2017.07.132
38. Wakjira, T., and Ebead, U., “Hybrid NSE/EB Technique for Shear Strengthening of Reinforced Concrete Beams Using FRCM: Experimental Study,” Construction and Building Materials, V. 164, 2018, pp. 164-177. doi: 10.1016/j.conbuildmat.2017.12.224
39. D’Ambrisi, A., and Focacci, F., “Flexural Strengthening of RC Beams with Cement-Based Composites,” Journal of Composites for Construction, ASCE, V. 15, No. 5, 2011, pp. 707-720. doi: 10.1061/(ASCE)CC.1943-5614.0000218
40. Babaeidarabad, S.; Loreto, G.; and Nanni, A., “Flexural Strengthening of RC Beams with an Externally Bonded Fabric-Reinforced Cementitious Matrix,” Journal of Composites for Construction, ASCE, V. 18, No. 5, 2014, p. 04014009 doi: 10.1061/(ASCE)CC.1943-5614.0000473
41. Yin, S.; Xu, S.; and Lv, H., “Flexural Behavior of Reinforced Concrete Beams with TRC Tension Zone Cover,” Journal of Materials in Civil Engineering, ASCE, V. 26, No. 2, 2014, pp. 320-330. doi: 10.1061/(ASCE)MT.1943-5533.0000811
42. Ebead, U.; Shrestha, K.; Afzal, M.; El Refai, A.; and Nanni, A., “Effectiveness of Fabric-Reinforced Cementitious Matrix in Strengthening Reinforced Concrete Beams,” Journal of Composites for Construction, ASCE, V. 21, No. 2, 2017, p. 04016084 doi: 10.1061/(ASCE)CC.1943-5614.0000741
43. Al-Salloum, Y.; Elsanadedy, H. M.; Alsayed, S.; and Iqbal, R. A., “Experimental and Numerical Study for the Shear Strengthening of Reinforced Concrete Beams Using Textile-Reinforced Mortar,” Journal of Composites for Construction, ASCE, V. 16, No. 1, 2012, pp. 74-90. doi: 10.1061/(ASCE)CC.1943-5614.0000239
44. Elghazy, M.; El Refai, A.; Ebead, U.; and Nanni, A., “Experimental Results and Modelling of Corrosion-Damaged Concrete Beams Strengthened with Externally-Bonded Composites,” Engineering Structures, V. 172, 2018, pp. 172-186. doi: 10.1016/j.engstruct.2018.06.037
45. ASTM C39/C39M-16b, “Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens,” ASTM International, West Conshohocken, PA, 2016, 7 pp.
46. ASTM C1609/C1609M-12, “Standard Test Method for Flexural Performance of Fiber-Reinforced Concrete (Using Beam With Third-Point Loading),” ASTM International, West Conshohocken, PA, 2012, 9 pp.
47. ISE/104 Committee, “BS 4449:2005: Steel for the Reinforcement of Concrete. Weldable Reinforcing Steel. Bar, Coil and Decoiled Product,” British Standards Institution, London, UK, 2005.
48. ASTM C109/C109M-05, “Standard Test Method for Compressive Strength of Hydraulic Cement Mortars,” ASTM International, West Conshohocken, PA, 2005, 9 pp.
49. Elghazy, M.; El Refai, A.; Ebead, U.; and Nanni, A., “Effect of Corrosion Damage on the Flexural Performance of RC Beams Strengthened with FRCM Composites,” Composite Structures, V. 180, 2017, pp. 994-1006. doi: 10.1016/j.compstruct.2017.08.069