InTrans / Aug 14, 2018

Determining in-place modulus of elasticity of stress-laminated timber decks using NDE

The objective of this study was to examine use of stress wave nondestructive evaluation (NDE) techniques to evaluate the in-place modulus of elasticity (MOE) of the laminations in stress-laminated timber bridge decks. Prior to bridge deck construction, longitudinal stress wave and transverse vibration NDE techniques were used to determine the MOE of 40 Southern Pine lumber specimens. A strong correlative relationship was found to exist between the MOE values obtained by these two techniques. Then, several bridge decks
were constructed from these specimens, and several types of instrumentation were used to measure the MOE of individual specimens within the decks prior to transverse stressing and at maximum transverse stress. Excellent agreement was found between the MOE values prior to bridge deck construction and those observed after deck construction. More importantly,
average MOE values obtained from measurements of
the individual laminations showed strong agreement
with bridge deck MOE.