Date of Graduation


Document Type


Degree Type



Statler College of Engineering and Mineral Resources


Chemical and Biomedical Engineering

Committee Chair

Eung Ha Cho.


Two kinds of GFRP (glass fiber reinforced plastics) composite materials were prepared and used in this study. One was E-glass/vinyl ester glass fiber reinforced polymer (plain GFRP) and the other was nano-GFRP prepared with the addition of 1 wt% of CloisiteRTM 10A nanoclay. These samples were aged in an alkaline solution (pH = 13.2) with 3560N (800-lbs), 2225N (500-lbs) and 885N (200-lbs) of sustained load, which were 50%, 31% and 12.5% of the tensile strength, respectively. Time to failure or tensile strength reduction was measured and used to determine durability of the samples in terms of Aging Index, which was proposed as the tensile strength reduction per day. The failed cross sectional areas of samples were examined by taking pictures with optical microscopes.;The nano-GFRP samples showed slightly higher durability than the plain GFRP samples under 2225N (500-lbs) sustained load. However, durabilities of the two kinds of samples were nearly the same under the 3560N (800-lbs) and 885N (200-lbs) sustained loads. It is has been found that the Aging Index proposed in this study varies as function of the square of applied stress.