Relationship between stress wave transmission time and bending strength of deteriorated oriented strandboard

ters and important residual strength Stress wave nondestructive evaluation (NDE) technologies are used in the inspec- properties of wood-based materials. tion of timber structures and frequently complement visual inspection procedures. In- A limited number of studies that fo­ spectors use stress wave NDE techniques to locate internal voids anddecayed or deteri- cused on prediction of residual strength orated areas in large timbers. Although those techniques have proven useful in have been completed. Aggour (1989), inspections, no information exists concerning the relationship between stress wave Pellerin et al. (19851, and Ross et al. transmission time and important residual strength properties of oriented strandboard (2001,1997) used stress wave techniques (OSB) that has been exposed to decay fungi. We examined the relationship between to assess the residual strength of piles, stress wave transmissiontime andbending strength of OSB subjected to brown-rot de- small clear specimens, and timbers. cay fungi. Stress wave transmission time was measured on small OSB specimens that Based on the encouraging results hadbeenexposed to brown-rot decayfungi for up to 11 weeks. Static bending tests were from these studies and the potential use then performed on the specimens. A strong relationship was observed between stress of stress wave NDE for inspection of wave transmission time and residual bending strength. wood composites, we designed a pilot study to examine the relationship between stress wave transmission times and residual bending strength of oriThe degradation of a wood aminations, often as a complement to vi- ented strandboard (OSB). This paper load-bearing (in-service) member may sual inspection procedures (Ross and summarizes the pilot study. be caused by a variety of agents. Organ- Pellerin 1994). Stress wave NDE techisms that derive their nourishment or niques are used to locate internal voids Materials and methods