Date of Graduation

2018

Document Type

Thesis

Degree Type

MS

College

Statler College of Engineering and Mineral Resources

Department

Civil and Environmental Engineering

Committee Chair

Hota V S GangaRao

Committee Co-Chair

Sushant Agarwal

Committee Member

Rakesh K Gupta

Committee Member

Ruifeng Liang

Abstract

In recent years, demand for Fiber Reinforced Polymer (FRP) Composites as a substitute of conventional materials has increased because of certain inherent advantages of FRPs over conventional materials such as concrete or steel. However, FRPs are also susceptible to degradation under both physical and chemical aging. To evaluate glass FRP composites aging behavior under harsh environments in a cost-effective manner, accelerated aging data are obtained under controlled lab environments, in short duration, to perform a correlation with data from naturally aged samples. Following the time-temperature superposition principle, the mechanical response in the field in a span of time of 75 to 100 years can be extrapolated to obtain the long-term degradation curves and strength reduction factors for design purposes.;In this work, a comprehensive literature review was performed to collect accelerated and natural aging data for glass fiber reinforced composites. Various methodologies were employed to normalize the data accounting for diversity in methods and materials so that the aging trends can be compared. To perform the aging correlation between the lab and field data, the Arrhenius type relationship was employed to extrapolate the data using the room temperature as reference temperature and to calculate activation energies.;Vinyl-ester was observed to have higher strength retention than Polyester in the majority of the scenarios evaluated in this study. In relation to mechanical properties, interlaminar shear strength yielded higher degradation in shorter periods of time and thus, it seems to be the controlling factor in determining the durability of GFRPs. Another dramatic strength reduction is noted in the lab under extreme alkaline environments in short duration which also shows much lower activation energy. Linear as well as nonlinear Arrhenius type relationships were evaluated and concluded that linear relationship provided more accuracy to determine the aging factors.

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