Nondestructive Methods of Evaluating Quality of Wood in Preservative-treated Piles

Nondestructive Methods of Evaluating Quality of Wood in Preservative-treated Piles
Author:
Publisher:
Total Pages: 12
Release: 2000
Genre: Nondestructive testing
ISBN:

Stress-wave-based nondestructive evaluation methods were used to evaluate the potential quality and modulus of elasticity (MOE) of wood in used preservative-treated Douglas-fir and southern pine piles. Stress wave measurements were conducted on each pile section. Stress wave propagation speeds in the piles were then obtained to estimate their MOE. This was followed by a sequence of tests conducted on octagon-shaped cants, on boards, and on small, clear wood specimens obtained from the piles. Statistical regression analyses revealed a strong correlation between the stress-wave-based MOE (MOEd) of piles and octagons and the corresponding flexural properties of boards and small, clear wood specimens determined by transverse vibration and static bending techniques, respectively. The results also indicated that used preservative-treated wood piles still contain material that has potential for use in exterior structural applications.

Several Nondestructive Evaluation Techniques for Assessing Stiffness and MOE of Small-diameter Logs

Several Nondestructive Evaluation Techniques for Assessing Stiffness and MOE of Small-diameter Logs
Author:
Publisher:
Total Pages: 16
Release: 2001
Genre: Timber
ISBN:

Many forests of the United States have large areas that contain trees of small diameter, mixed species, and undefined quality. Because these areas are at risk from attack by insects, disease, and uncontrollable wild fires, it is essential to find ways to increase the incentive to harvest this small-diameter material. One way to do this is to develop cost-effective products for the fiber from these trees. Nondestructive technology needs to be developed to evaluate the potential quality of stems and logs obtained from trees in such ecosystems. Static bending, transverse vibration, and longitudinal stress wave techniques are frequently used to assess the modulus of elasticity (MOE) of lumber. Excellent correlations between MOE values obtained from these techniques have been reported. The objective of this study was to investigate the use of these techniques to evaluate the flexural stiffness and MOE of small-diameter logs. A total of 159 red pine and jack pine logs were obtained from northern Michigan and were assessed nondestructively using these techniques. Statistical comparisons between stiffness and MOE values obtained from each technique were then examined. Results of this study demonstrated that strong relationships exist between the log properties determined by the three techniques, longitudinal stress wave, transverse vibration, and static bending. Developed models allow for the prediction of static bending properties of logs at levels of accuracy previously considered unattainable. This indicates that any of these techniques can be used to sort small diameter logs with reasonable accuracy.

In Situ Assessment of Structural Timber

In Situ Assessment of Structural Timber
Author: Bohumil Kasal
Publisher: Springer Science & Business Media
Total Pages: 140
Release: 2011-03-10
Genre: Technology & Engineering
ISBN: 9400705603

Wood is one of the most intriguing structural materials and the only one that is truly renewable. Along with stone, wood is the oldest structural material on the planet and has been extensively used throughout human history. Due to its aesthetical value and positive environmental impact, wood has experienced a renaissance in construction. As a biodegradable, hygroscopic, non-isotropic material, wood presents special challenges for a professional and requires through knowledge ranging from biology to continuum mechanics. This state-of-the-art report reflects the current knowledge in the area of in situ assessment of the physical and mechanical properties of wood structures. Nondestructive, semi-destructive and destructive methods are described in a systematic manner where technology, equipment and limitations are discussed. Some of the discussed methods are used in other materials such as masonry and concrete. Most of the methods, however, are specific to wood and special qualifications are required to understand and apply these methods effectively. Existing methods are constantly improved and new methods are being developed. This report includes methods that are used in practice or have shown significant promise and have a body of knowledge that supports statements made in this report. This is a useable tool for professionals, researchers, educators and students