Delamination Evaluation of in-Service Glulam Beams and other Structural Members Via Ultrasonics

Abstract

The importance of nondestructive techniques for assessing the internal conditions of structural members is generally accepted for old or more recent buildings (Ross and Pellerin 1994; Pellerin and Ross 2002, Tanaka et al. 1998; Brashaw et al. 2005; Wacker et al. 2007). Efforts to preserve buildings that have nationally significant importance have been based on the development of nondestructive techniques able to assess their mechanical performances (Wang X and Wacker 2006; Sandoz and Benoit 2007; Lee et al. 2007; Divos et al. 2007). The overall goal of these efforts is to preserve to the maximum possible extent of the historical materials used for the monuments. On the other hand, in recent years, the stability of existing glulam structures became an important issue after the collapse of some of the early structures. For example, in Germany on Jan.2, 2006, 15 people, most of them children on a school holiday, died when the roof of a skating rink fell in the Bavarian town of Bad Reichenhall, after heavy wet snow falls (Associated Press 2006).