InTrans / Aug 14, 2018

Field performance of timber bridges: 7. Connell Lake stress-laminated deck bridge

Condition assessment is an important first step in the restoration
of any historic structure. Immunodiagnosis of wood decay fungi, nondestructive evaluation (NDE) stress wave mapping, and compression perpendicular to grain were used to evaluate white pine roof truss timbers from the Blacksmith Shop of the Quincy Mining Company in Keweenaw National Historical Park. Immunodiagnosis indicated that areas in the timber had been exposed to decay fungi. Stress wave NDE mapping located voids in the timbers tested. Compression perpendicular to the grain correlated with NDE findings.