Stressed timber bridge decks are constructed by pressure laminating thin wooden members into solid slab, using a simple post-tensioning system. Economic studies indicate that finding ways to lower timber costs is important in making this type of structure more cost competitive. Recently, stressed timber decks reinforced with steel sandwich plates have been introduced. They are inherently more stiff, ductile, and resistant to creep than their non-reinforced predecessors. A 'bilayer' reinforced stressed timber deck configuration, using two separate layers of relatively small, low-cost deck boards, was investigated. Full-scale laboratory testing was performed to measure stiffness, efficiency, and material stresses of a bilayer prototype deck constructed with combinations of three prestressing pressures and six steel reinforcement plate levels. Both static and dynamic loads were applied to the deck. The bilayer prototype demonstrated predictable, orthotropic behavior for decks containing as low as 1.64 percent steel by volume. In a nondimensional comparison, the bilayer was found to be slightly less efficient than single-layered decks, but comparable. Application of heavy static and dynamic loads did not introduce any measurable interlaminate slip. Whereas an economical bilayer configuration is possible when steel sandwich plates are present, additional testing is needed to further establish comprehensive design criteria for this type of structure.
|Original language||English (US)|
|Title of host publication||Transportation Research Record|
|Number of pages||8|
|State||Published - Oct 1 1993|
ASJC Scopus subject areas
- Civil and Structural Engineering
- Mechanical Engineering