STUDY ON REINFORCEMENT OF SPLITTING TIMBER BY DRIVING WEDGE TEST

Abstract

A method of driving wedge test was proposed in order to qualify the effect of reinforcement on splitting strength of timber. The wedge was quasi-statically driven into timber in its longitudinal direction by structural testing machine, during which the load and displacement were measured until splitting failure. Japanese cedar was employed for the substrate. Eleven sorts of reinforcements, i.e., plywood, rubber plate, steel sheet, punched aluminum plate, PVC sheet, jute, steel wire cloth, glass fiber cloth, carbon fiber cloth, carbon fiber felt, and polyester fiber cloth, were tested. They were attached to the substrate with three types of adhesives, i.e., epoxy resin, poly vinylacetate emulsion, and cyanoacrylate adhesives. The driving wedge test revealed the relationships between the strength of reinforcement and the load of splitting. A high correlation between splitting strength and driving displacement was observed. These results suggest that the simple test method provides consistent data on the splitting behavior of reinforced timber.