Title: Experimentally Measured Tensile Performance of Pultruded FRP at Elevated Temperatures

Authors: Capra K. Williams and Kevin Q. Walsh

DOI: 10.33599/nasampe/c.24.0329

Abstract: As the composites industry is moving toward implementing pultruded FRP as a viable structural material, various manufacturing and construction decisions must be considered when designing FRP to comply with current building codes and standards' elevated temperature and fire performance requirements. Some examples include the type of resin, fire retardant additives, structural cross-section, and the amount and type of fiber reinforcement utilized in the composite. In the current study, the experimentally measured performance of pultruded FRP at elevated temperatures from 6 prior studies was amalgamated. These studies measured the elevated temperature performance of pultruded shapes under various loading conditions, including tension, compression, flexure, and bending under multiple different manufacturing considerations, including the fiber orientation, flame retardant additives, flame retardant surface treatments, resin, and the performance of varying cross sections under elevated temperatures. The authors carried out a subsequent and novel experimental program comprising 90 tests to provide additional information for pultruded FRP structural members, emphasizing the following design considerations: 1. Testing an elevated temperature range viable for most civil structures; and 2. Testing pultrusion angles of 0° and 90° to gain information on the strongest and weakest loading conditions. The authors concluded that strength reduction factors for elevated temperatures in ASCE 74 may need to be revised, pending the results of further testing in a broader range of available materials and shapes. In the currently reported experimental study, the authors measured a lower average tensile strength adjustment factor at 32.2 °C for coupons at a 0° pultrusion angle versus the provisions of ASCE 74 (0.89 versus 1.00, respectively) but a higher average tensile strength adjustment factor at 48.9 °C versus the requirements of ASCE 74 (0.90 versus 0.70, respectively). Therefore, the provisions of ASCE 74 may be non-conservative at lower temperatures.

References: 1. IBC (International Building Code). Chapter 26: Plastics. Washington DC: ICC(International Code Council), 2021. 2. ASCE (American Society of Civil Engineers). ASCE 74. Reston: ASCE, 2023 3. Mouritz, A.P. “Post-fire flexural properties of fibre-reinforced polyester, epoxy, and phenolic composites.” Journal of Material Science. 37(2002): 1377-1386. [https://doi.org/10.1023/A:1014520628915] 4. Dowbysz, A., Samsonowicz, M., and Kukfisz, B. “Modification of Glass/Polyester Laminates with Flame Retardants.” Materials 2021 14 (24) (2021):7901 [https://doi.org/10.3390/ma14247901] 5. Mouritz, A.P., and Gibson, A.G. Fire Properties of Polymer Composite Materials. Netherlands: Springer Netherlands, 2006. [https://doi.org/10.1007/978-1-4020-5356-6] 6. Stevens, M.G. “Factors Affecting ASTM-E84 Flame Spread and Smoke Values.” Composites 2004 Convention and Trade Show. Tampa, FL, October 6-8, 2004. 7. National Science Foundation and CEP. “Polymer Composite Utility Poles Offer Grid Resilience to Wildfires.” AIChE (The Global Home of Chemical Engineers), 2021 8. Aydin, F. “Effects of various temperatures on the mechanical strength of GFRP box profiles.” Construction and Building Materials 127(2016): 843-849. [http://dx.doi.org/10.1016/j.conbuildmat.2016.09.130] 9. Correia, J.R., Gomes, M.M., Pires, J.M., and Branco, F.A. “Mechanical behavior of pultruded glass fibre reinforces polymer composite at elevated temperature: Experiments and model assessment.” Composite Structures 98(2013): 303-313. [http://dx.doi.org/10.1016/j.compstruct.2012.10.0] 10. Khaneghahi, M.H., Najafabadi, E.P., Bazil, M., and Oskouei, A.V. “The effect of elevated temperatures on the compressive section capacity of pultruded GFRP profile.” Construction and Building Materials 249(2020): 118725. [https://doi.org/10.1016/j.conbuildmat.2020.118725] 11. Najafabadi, E. P., Khaneghahi, M.H., Amiri, H.A., Estekanchi, H.E., and Ozbakkalglu, T. “Experimental investigation and probabilistic models for residual mechanical properties of GFRP pultruded profiles exposed to elevated temperatures.” Composite Structures, 211(2019): 610-629. [https://doi.org/10.1016/j.compstruct.2018.12.032] 12. Wang K., Young, B., and Smith, S.T. “Mechanical properties of pultruded carbon fibre-reinforced polymer (CFRP) plates at elevated temperatures.” Engineering Structures 33 (2011). [https://doi.org/10.1016/j.engstruct.2011.03.006] 13. Wong, P.M.H., Davies, J.M., and Wang, Y.C. “ An experimental and numerical study of the behavior of glass fibre reinforced plastics (GRP) short columns at elevated temperatures.” Composite Structures 63(2004): 33-34. [https://doi.org/10.1016/S0263-8223(03)00122-3] 14. ASTM Standard D638-22, 2022, “Standard Test Method for Tensile Properties of Plastics” ASTM International, West Conshohocken, PA,2022, [DOI: 10.1520/D0638-22] 15. Pirchio D., Althouse J., Madlem T., Denavit M.D., Weldon B.D., and Walsh K.Q. “Tensile strength and modulus of FRP pultruded composites at varying load angles relative to the pultrusion direction.” Construction and Building Materials, 385 (2023): 131477. [https://doi.org/10.1016/j.conbuildmat.2023.131477]

Conference: CAMX 2024 | San Diego CA

Publication Date: 2024/9/9

SKU: TP24-0000000329

Pages: 12

Price: $24.00