Retrofitting of Flange Notched Wood I-Joists with Glass Fiber Reinforced Polymer (GFRP) Plates

Prefabricated composite wood I-joists are very common in North America as a building materials for light-frame wood construction. The capacity and the failure pattern of prefabricated composite wood I-joists in the presence of a flange notch was experimentally investigated with a total of 6 specimens with various sizes and locations of notches having a span length of 6.1 m (20 feet). Test results showed that the presence of a notch reduced the capacity significantly up to 75% compared to I-joists having no flange notch depending on the size and location of the notch. The web of the control I-joists with no opening failed in flexure in the mid-span whereas the top-flange failed in compression and bottom-flange failed in tension. On the other hand, most of the I-joists with a notch failed in flexure at the notch location. The performance of flange notched I-joists retrofitted with glass fiber reinforced polymer (GFRP) plate was also investigated on another 18 specimens. After retrofit, brittle premature failure of I-joists was prevented with a significant increase in capacity up to 307% compared to the I-joists with notches was achieved. Based on the experimental results, a prediction model was developed and validated with the experimental results.