Title:
Alkaline Attack on Cement or Lime Mortar and Glass Fiber-Reinforced Polymer Rods
Author(s):
Manuel A. G. Silva and Miguel Estêvão
Publication:
Materials Journal
Volume:
117
Issue:
1
Appears on pages(s):
97-106
Keywords:
environmental degradation; glass fibers; porosity; resin; strength
DOI:
10.14359/51719071
Date:
1/1/2020
Abstract:
Glass fiber-reinforced polymer rods, both bare and embedded in concrete or lime mortar, were immersed in an alkaline solution at 20°C for up to 6 months and tested to find the influence of the protective covers on the degradation of the rods. Diffusion and porosimetry studies were used to interpret the results. Reduction of the proportion of larger pores in the mortar cylinders altered the transport of contaminant to the reinforcing bars. Accelerated effects due to immersion in solution at 60°C caused marked degradation of the rods. SEM images revealed damage to the matrix and the interface fiber-resin, mostly noticeable on the resin matrix and in the peripheral region of the rods. Severe loss of capacity of energy absorption was found in low-velocity impact tests after exposure to solution at 20°C for more than 5000 hours. Globally, results showed that the embedment delayed the initiation of damage but did not shield the rods against the maximum intensity of degradation by the alkaline contaminant.
Related References:
1. Aiello, M. A., and Ombres, L., “Environmental Effects on the Mechanical Properties of Glass-FRP and Aramid-FRP Rebars,” Mechanics of Composite Materials, V. 36, No. 5, 2000.
2. Dejke, V., “Durability of FRP Reinforcement in Concrete,” thesis for licentiate in engineering, Chalmers University of Technology, Gothenburg, Sweden, 2001.
3. Chen, Y., and Julio, F., “Durability Prediction for GFRP Reinforcing Bars Using Short-Term Data of Accelerated Aging Tests,” Journal of Composites for Construction, ASCE, V. 10, No. 4, 2006, p. 1 doi: 10.1061/(ASCE)1090-0268(2006)10:4(279)
4. Masmoudi, R. B.; Nkurunziza, G. C.; Benmokrane, B.; and Cousin, D., “Durability of Glass FRP Composite Bars for Concrete Structure Reinforcement under Tensile Sustained Load in Wet and Bare Rods Environments,” Congrès annuel de la Société Canadienne de Génie Civil, Moncton, NB, Canada, GCA400-1/9, 2003.
5. Chen, Y., and Julio, F., “Accelerated Aging Tests for Evaluations of Durability Performance of FRP Reinforcing Bars for Concrete Structures,” Composite Structures, V. 78, No. 1, 2007, pp. 101-111. doi: 10.1016/j.compstruct.2005.08.015
6. Micelli, F., and Nanni, A., “Durability of FRP Rods for Concrete Structures,” Construction and Building Materials, V. 18, No. 7, 2004, pp. 491-503. doi: 10.1016/j.conbuildmat.2004.04.012
7. Ceroni, F.; Cosenza, E.; Gaetano, M.; and Pecce, M., “Durability Issues of FRP Rebars in Reinforced Concrete Members,” Cement and Concrete Composites, V. 28, No. 10, 2006, pp. 857-868. doi: 10.1016/j.cemconcomp.2006.07.004
8. Robert, M., and Benmokrane, B., “Effect of Aging on Bond of GFRP Bars Embedded in Concrete,” Cement and Concrete Composites, V. 32, No. 6, 2010, pp. 461-467. doi: 10.1016/j.cemconcomp.2010.02.010
9. “Technical Specification 2/10 Tyfo Fibr Re-Bar GRB,” Fyfe Co., LLC, 2005, pp. 7-10.
10. NP EN 197-1, “Cimento – Parte 1: Composição, Especificação e Critérios de Conformidade para Cimentos Correntes,” 2012. (in Portuguese)
11. Kim, Y.-Y.; Lee, K.-M.; Bang, J.-W.; and Kwon, S.-J., “Effect of W/C Ratio on Durability and Porosity in Cement Mortar with Constant Cement Amount,” Advances in Materials Science and Engineering, V. 2014, 2014.
12. Vikrant, B. S., “Strength Degradation of GFRP Bars,” MSc thesis, Virginia Polytechnic and State University, Blacksburg, VA, Sept. 2002.
13. Stakgold, I., Boundary Value Problems of Mathematical Physics, SIAM, MacMillan, 1968.
14. Micelli, F., and Nanni, A., Mechanical Properties and Durability of FRP Rod, CIES 00-22, University of Missouri–Rolla, Rolla, MO, 2001.
15. Chin, J. W.; Nguyen, T.; and Aouadi, K., “Effects of Environmental Exposure on Fiber-Reinforced Plastic (FRP) Materials Used in Construction,” Journal of Composites Technology and Research, 1997, pp. 205-213.
16. Sawpan, M. A., “Effects of Alkaline Conditioning and Temperature on the Properties of Glass Fiber Polymer Composite Rebar,” Polymer Composites, V. 37, No. 11, 2015, pp. 3181-3190.
17. Apicella, A.; Migliaresi, C.; Nicolais, L.; Iaccarino, L.; and Roccotelli, S., “The Water Ageing of Unsaturated Polyester-Based Composites: Influence of Resin Chemical Structure,” Composites, V. 14, No 4, Oct. 1983.
18. Joannie, W., “Sorption and Diffusion of Water, Salt Water, and Concrete Pore Solution in Composite Matrices,” Journal of Applied Polymer Science, V. 71, No. 3, 1999, pp. 483-492. doi: 10.1002/(SICI)1097-4628(19990118)71:33.0.CO;2-S
19. ISO 1172, “Textile-Glass-Reinforced Plastics: Determination of the Textile-Glass and Mineral-Filler Content—Calcination Methods,” International Organization for Standardization, London, UK, 1996.
20. Papayianni, I., and Stefanidou, M., “Strength-Porosity Relationships in Lime-Pozzolan Mortars. Construction and Building Materials,” Construction and Building Materials, V. 20, No. 9, Nov. 2006, pp. 700-705.
21. Kumar, R., and Bhattacharjee, B., “Porosity, Pore Size Distribution and In Situ Strength of Concrete,” Cement and Concrete Research, V. 33, No. 1, 2003, pp. 155-164. doi: 10.1016/S0008-8846(02)00942-0
22. Mindess, S.; Young, J. F.; and Darwin, D., Concrete, Prentice Hall, Englewood Cliffs, NJ, 1981.
23. Zhao, H.; Xiao, Q.; Huang, D.; and Zhang, S., “Influence of Pore Structure on Compressive Strength of Cement Mortar,” Scientific World Journal, V. 2014, Article ID 247058. http://dx.doi.org/10.1155/2014/24705810.1155/2014/247058
24. Chen, X. D.; Wu, S. X.; and Zhou, J. K., “Influence of Porosity on Compressive and Tensile Strength of Cement Mortar,” Construction and Building Materials, V. 40, 2013, pp. 869-874. doi: 10.1016/j.conbuildmat.2012.11.072
25. Wong, H. S., and Buenfeld, N. R., “Determining the Water-Cement Ratio, Cement Content, Water Content and Degree of Hydration of Hardened Cement Paste: Method Development and Validation on Paste Samples,” Cement and Concrete Research, V. 39, No. 10, 2009, pp. 957-965. doi: 10.1016/j.cemconres.2009.06.013
26. ASTM D7028-07(2015), “Standard Test Method for Glass Transition Temperature of Polymer Matrix Composites by Dynamic Mechanical Analysis (DMA),” ASTM International, West Conshohocken, PA, 2015, 13 pp.
27. Fernandez-Cantelia, A.; Arguellesa, A.; Vina, J.; Ramulu, M.; and Kobayashi, A. S., “Dynamic Fracture Toughness Measurements in Composites by Instrumented Charpy Testing: Influence of Aging,” Composites Science and Technology, V. 62, No. 10-11, 2002, pp. 1315-1325. doi: 10.1016/S0266-3538(02)00074-X
28. ASTM D6110-18, “Standard Test Method for Determining the Charpy Impact Resistance of Notched Specimens of Plastics,” ASTM International, West Conshohocken, PA, 2018, 17 pp.
29. ISO 179-1:2010, “Plastics—Determination of Charpy Impact Properties,” International Organizationfor Standardization, London, UK, 2010.
30. Duell, J. M., “Impact Testing of Advanced Composites,” Advanced Topics in Characterization of Composites, 2004, pp. 97-112.
31. Delfosse, D., and Poursartip, A., “Energy-Based Approach to Impact Damage in CRFP Laminates,” Composites. Part A, Applied Science and Manufacturing, V. 28A, No. 7, 1997, pp. 647-5. doi: 10.1016/S1359-835X(96)00151-0