Pultruded GFRP Reinforcing Bars with Carbon Nanotubes

Abstract

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.