This paper describes the testing plan and current progress for assessing the efficacy of using ground-penetrating radar (GPR) to detect fungal decay within Douglas-fir beams. Initially, the beams were assessed using a variety of physical, mechanical, and nondestructive evaluation (NDE) test methods including micro-resistance drilling, Janka hardness, ultrasonic transmission, and GPR. After initial baseline assessment, beams were inoculated with brown rot fungus, Fomitopsis pinicola, and exposed to above-ground conditions approximately 25 miles (40 km) north of Gulfport, Mississippi, USA. Beam specimens will be removed from the exposure site at six-month intervals and scanned using GPR to detect and assess interior rot. After GPR scanning, micro-resistance drilling and ultrasonic transmission testing will be performed. Finally, the beams will be cut into 2-in. segments for Janka hardness testing, which will give the most definitive information regarding the spread of the brown rot fungus throughout the beams. The GPR scans will be compared to the hardness testing, micro-resistance drilling, and ultrasonic testing results to evaluate the ability of GPR to detect interior rot within the beams.
1. Green D.W., M. Begel, W. Nelson. 2006 Janka hardness using nonstandard specimens. Research Note FPL-RN-
0303. U.S. Department of Agriculture, Forest Service, Forest Products Laboratory, Madison, WI, p 13.
2. Hans, G., D. Redman, B. Leblon, J. Nader, A. La Rocque. 2015a. Determination of log moisture content using
early-time ground penetrating radar signal, Wood Material Science & Engineering, 10:1, 112-129, DOI:
3. Hans, G., D. Redman, B. Leblon, J. Nader, A. La Rocque. 2015b. Determination of log moisture content using
ground penetrating radar (GPR). Part 1. Partial least squares (PLS) method. Holzforschung, v 69, n 9, p 1117-
1123, November 1, 2015.
4. Hans, G., D. Redman, B. Leblon, J. Nader, A. La Rocque. 2015c. Determination of log moisture content using
ground penetrating radar (GPR). Part 2. Propagation velocity (PV) method. Holzforschung, v 69, n 9, p 1125-
1132, November 1, 2015.
5. Maï, T.C., Z.M. Sbartaï, F. Bos, S. Razafindratsima, F. Demontoux. 2014. Non-destructive evaluation of timber
structures using GPR technique. Proceedings of the 15th International Conference on Ground Penetrating
Radar, p 218-222, Dec. 1, 2014.
6. Maï, T.C., S. Razafindratsima, Z.M. Sbartaï, F. Demontoux, F. Bos. 2015. Non-destructive evaluation of
moisture content of wood material at GPR frequency. Construction and Building Materials, v 77, p 213-217,
February 15, 2015.
7. Martínez-Sala, R., I. Rodríguez-Abad, R. Diez Barra, R. Capuz-Lladró. 2013. Assessment of the dielectric
anisotropy in timber using the nondestructive GPR technique. Construction and Building Materials, v 38, p 903-
911, January 2013.
8. Muller W. 2003. Timber girder inspection using ground penetrating radar. Insight Nondestr Test Cond Monit.
9. Riggio, M., R.W. Anthony, F. Augelli, B. Kasal, T. Lechner, W. Muller, T. Tannert. 2014. In situ assessment of
structural timber using non-destructive techniques. Materials and Structures/Materiaux et Constructions, v 47, n
5, p 749-766, 2014.
10. Rodriguez-Abad, I., R. Martinez-Sala, F. Garcia-Garcia, R. Capuz-Lladro, R. Diez Barra. 2011. Non-destructive
characterization of maritime pine sawn timber dielectric anisotropy by means of GPR. 6th International
Workshop on Advanced Ground Penetrating Radar, IWAGPR, 2011.
11. Ross, R.J. (Ed.). 2015. Nondestructive Evaluation of Wood: Second Edition . General Technical Report FPLGTR-
238. Madison, WI, U.S. Department of Agriculture, Forest Service, Forest Products Laboratory, 169 p.
12. Ross, R.J. 2010. Wood Handbook: Wood as an Engineering Material . Centennial ed. General technical report
FPL; GTR-190. Madison, WI: U.S. Dept. of Agriculture, Forest Service, Forest Products Laboratory, 2010: 1 v.
13. United States. Department of Transportation. Federal Highway Administration. Programs Office. Office of
Infrastructure. Office of Bridges and Structures. National Bridge Inventory Library. Table of Bridges by Deck
Structure Type, 2014. http://www.fhwa.dot.gov/bridge/nbi/no10/deck14.cfm
14. Wacker, J.P., C.A. Senalik, X. Wang, F. Jalinoos. (Pending). Effectiveness of Several NDE Technologies in
Detecting Internal Moisture and Artificial-Decay in Sawn Timber and Glulam. Proc. WCTE 2016 World Conf.
Timber Eng. Aug. 22-25, Vienna, Austria.
8 Page Views
0 PDF Downloads
0 Facebook Shares