Composite structures paper
Aboelseoud, MA & Myers, JJ 2014, 'Effects of environmental exposure on hybrid composite beam (HCB) bridges', in ST Smith (ed.), 23rd Australasian Conference on the Mechanics of Structures and Materials (ACMSM23), vol. II, Byron Bay, NSW, 9-12 December, Southern Cross University, Lismore, NSW, pp. 651-656. ISBN: 9780994152008.
This project involves the field evaluation of a new hybrid composite beam (HCB) recently used to construct three bridges in Missouri, USA. The HCB is comprised of self-consolidating concrete (SCC) that is poured into classical arch shape and tied at the ends by conventional prestressing tendons. The concrete and steel are tucked inside fiberglass shell and the voids are filled with polyisocyanurate (polyiso) foam. This paper examined the durability of a commercial GFRP laminate used to encase the HCB elements in one of the recently constructed bridges. The E-glass/vinylester laminate was subjected to two different aging regimes. The first regime consisted of continuous salt fog exposure for 3072 hr. (128 days), while the second regime included applying different levels of sustained stress along with 350 different thermal cycles in a computer-controlled environmental chamber. The thermal cycling consisted of 50 freeze-thaw cycles that simulated the winter season effects. Then, the summer season effects were simulated by alternating groups of 50 high temperature cycles and 50 high relative humidity cycles for a total of 150 cycles each. The results of this study demonstrated that the GFRP shell, and subsequently the HCB as a whole, has excellent durability in relation to the expected weathering exposures in the mid-west United States.