Abstract
In order to reuse waste concrete form plywood effectively, we developed a way of reconstituting the waste plywood by reinforcing it with new veneers at both surfaces. We first prepared the core plywood by sanding, trimming and end or side jointing the waste plywood, and then reinforced it with new veneers at its face and back. We estimated the practical performance of the core plywood and the reconstituted plywood according to the standard testing methods. The core plywood, which consisted of waste plywood pieces joined together, did not have enough bending properties. The reinforcement with new veneers at the face and back of the core plywood, however, successfully improved the properties of the resultant reconstituted plywood, which satisfied the requirements for concrete form plywood. The adhesive properties between the core plywood and the surface veneers with a water-based polymer-isocyanate adhesive satisfied the Japanese Agricultural Standard for type-I plywood. The yield of reconstituted plywood was greatly influenced by the size of the waste plywood, and amounted to 39.6 to 50.0% of the collected waste plywood.
