Glued structural products made of beech wood: Quality of the raw material and gluing issues

Hardwoods are becoming increasingly important in Europe for the use as structural material, both as solid wood and engineered structural products. The recent constitution of a new standardization working group at European level (CEN TC124 / WG3 / TG1) for the drafting of a harmonized standard regulating the production and characterization of glulam beams made of hardwoods proves this growing interest. In Italy, the great abundance of beech forests has led to the demand of a research project to investigate the use of this species in construction. Specifically, the study, among other things, deals with the production of structural glued products made of beech. The research starts with the characterization of the raw material, developing the strength grading of the beech boards, both by visual and machine methods. At the same time, the study addresses the comparison of different gluing parameters, such as the pressing process and the adhesive used to achieve an adequate structural bonding between lamellas. The paper reports the results concerning the mechanical characterization of beech sawn wood from different Italian Regions and the first outcomes encountered during the selection of the different structural gluing parameters for the production of CLT