Pultruded GFRP Reinforcing Bars with Carbon Nanotubes
Pultrusion is a renowned method in industry to produce glass fiber reinforced polymer (GFRP) reinforcing bars. Pristine multiwalled carbon nanotubes (P-MWCNTs) and multiwalled carbon nanotubes (MWCNTs) with carboxyl functional group (COOH-MWCNTs) were dispersed into the vinyl ester resin to produce GFRP bars. The GFRP bars were produced using a pultrusion prototype facility recently developed at the University of New Mexico. Direct tension and short beam shear tests were conducted to determine the mechanical properties of the nano-modified GFRP reinforcing bars. The experimental program shows the ability of MWCNTs to improve the mechanical behavior of GFRP reinforcing bars by 20% and 111% for the tensile and shear strength, respectively. Of particular interest is the absence of the typical broom failure observed in neat GFRP when functionalized MWCNTs were used. The proposed nano-modification of GFRP using MWCNTs might enable overcoming many of the current limitations of GFRP reinforcing bars.
This work is funded by the TranSET University Transportation Center (UTC). The authors greatly acknowledge this support.
- 4.CSA S6. (2010). Canadian highway bridge design code (CHBCD). Mississauga: Canadian Standards Association International.Google Scholar
- 8.Eklund, P., Ajayan, P., Blackmon, R., Hart, A. J., Kibng, J., Pradhan, B., et al. (2007). International assessment of research and development of carbon nanotube manufacturing and applications. Baltimore: World Technology Evaluation Center.Google Scholar
- 10.ASTM D7205/D7205M-06. (2016). Standard test method for tensile properties of fiber reinforced polymer matrix composite bars. West Conshohocken: ASTM International.Google Scholar
- 11.ASTM D4475-02. (2016). Standard test method for apparent horizontal shear strength of pultruded reinforced plastic rods. West Conshohocken: ASTM International.Google Scholar
- 12.ASTM D3171-15. (2015). Standard test methods for constituent content of composite materials. West Conshohocken: ASTM International.Google Scholar
- 13.Reda Taha, M., Chennareddy, R., & Riad, A. (2017) Smart ester-based high performance pultruded GFRP with self-sensing capabilities and methods of making, Provisional US Patent filed, October 2017.Google Scholar