• Silva, Manuel A. G.
• Pinho, Fernando F. S.
• Estêvão, Miguel

Abstract

<p>The work is focused on environmental degradation of bars of glass fiber reinforced polymers (GFRP) a type of structural reinforcement (fib, 2007) often used in masonry (Tumialan and Nanni, 2002; Mohamed et al. 2012), waterfront structures and bridges (Worner, 2015), and in special cases where steel may cause adverse operational consequences. Uncertainties on service life of those rods under aggressive environmental conditions require further data despite some existing literature on their durability. Those factors motivated an experimental program on the effects of sorption of (i) salt water, with salinity 50g/l, and (ii) an alkaline solution (pH 13.6) on bars of GFRP, including the study of protection given by concrete cover since rods are usually embedded. Diffusion of contaminants was modeled and changes on chemical composition and on the glass transition temperature (Tg) of resin, and on porosimetry of concrete mortar were examined. Redistribution and progressive reduction of the number of larger pores with aging was detected, though causing little effect on porosity, with salt water found more influential than the alkaline solution. Modification of Tg was negligible. Microscopic electronic scanning (SEM) confirmed damage concentration on the matrix, and mostly in the peripheral region of rods. Alterations of proportion of chemical elements were summarized and examined. Interpretation and correlation of data shed light on mechanisms of failure of structural members reinforced with GFRP bars.</p>

Topics

• impedance spectroscopy
• pore
• polymer
• scanning electron microscopy
• glass
• glass
• steel
• chemical composition
• thermogravimetry
• glass transition temperature
• aging
• porosity
• resin
• aging
• porosimetry