Comparative Evaluation of Investigation Testing Methods in Timber Elements considering Moisture Content

Wood components in existing buildings suffer from deterioration and damage due to environmental conditions and loading effects. Their preservation strongly depends on the knowledge level of their onsite condition supported by the application of low-intrusive methods of investigation. Estimating the mechanical performance of wood in constructions cannot disregard the evaluation of moisture content. In this paper, 31 wood elements (19 recovered from disassembled buildings and 12 new) underwent a series of non-destructive tests (i.e., ultrasonic and sonic stress wave methods) and semi-destructive tests (i.e., resistance drilling and pin penetration). Red/white firs and pine species constituted the recovered elements; red fir and larch the new ones. The effect of moisture content on the results of low-intrusive methods was estimated by either electric or electromagnetic devices. Destructive tests (in bending and compression) were also carried out on 10 recovered and six new elements, and results were correlated with those of semi-destructive tests.