The technology was developed by Habib Dagher and Steve Shaler, director and associate director respectively at AEWC, and by Beckry Abdel-Magid, AEWC engineer and a professor at Winona State University in Minnesota. Their invention allows common adhesives to be used to bond layers of wood with a FRP panel.
The technology is known as RESPI™, which stands for resin-starved pultruded-impregnated. RESPI™ technology provides a simple, inexpensive, commercially viable method for reinforcing structural wood products such as beams, I-joists or flat panels (plywood).
The inventors have performed pilot studies of RESPI™ over the past five years and have found that a panel reinforcement of 2% of a laminated beam by volume can increase the bending strength of the beam by over fifty percent. "The Center has been responsible for innovative bridge and pier construction using composite wood materials all over the state in over a dozen demonstration projects" says Dagher. "Two projects, a pier in Bar Harbor and a bridge in Medway, both utilize RESPI™ panels. We are very excited that this cost-efficient, effective technology developed in University of Maine laboratories has already benefited Maine’s communities."
In addition to increasing the strength, stiffness and ductility of wood composites, RESPI™ reinforced beams allow for longer spans, lower depths and lighter structures.
The AEWC was established by UMaine to develop the underlying science and engineering principles needed to produce low-cost, high-performance materials made of wood and non-wood components. These materials promise to be less expensive and more effective than concrete and steel, and they serve the state’s economy by adding value to low grade wood and wood by-products which have heretofore been underutilized, if not totally discarded.