Strength Class Prediction of Sardinia Grown Timber by Means of Non Destructive Parameters

Abstract:

In Italy timber and wood products are becoming increasingly used for building constructions due to their excellent physics and mechanical properties. International Codes require the use of wood previously graded according to the current regulation. This paper reports the preliminary results of an experimental campaign aimed at verifying the reliability of the use of Sardinian timber as structural material. For this purpose Maritime Pine boards from two different Sardinian areas have been analyzed and visual strength graded. Physical and morphological properties (density, knots, clusters knot, resin pockets, deviation of the grain, annual ring width position of board respect to the pith, humidity, etc.) along with mechanical and non destructive properties (elastic modulus, tensile strength, ultrasonic pulse velocity) have been checked. Timber properties have been statistically evaluated in order to identify the performance of the base material. Regression analyses have been carried out by studying the correlation between non destructive parameters and mechanical properties in order to define a criterion for predicting the strength class of the base material.

• Periodical: Advanced Materials Research (Volume 778)
• Pages: 191-198
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.778.191
• Online since: September 2013
• Authors: Giovanna Concu, Barbara de Nicolo, Nicoletta Trulli, Monica Valdés, Massimo Fragiacomo
• Keywords: Locally Grown Timber, Mechanical Properties of Timber Elements, Non Destructive Parameters, Sonic Testing, Visual Grading

References

[1] A. Buchanan, B. Honey. Energy and Carbon Dioxide Implications of Building Constructions. Energy and Building. 20. (1994) 205-217.

DOI: 10.1016/0378-7788(94)90024-8

[2] UNI EN 338. Structural Timber: Class Strength. (2009).

[3] UNI EN 14081-1. Timber Structures. Strength graded structural timber with rectangular cross section. Part I: General requirements. (2011).

DOI: 10.3403/30040180u

[4] G. Concu, B. De Nicolo & M. Valdés, M. Fragiacomo, A. Menis & N. Trulli. Experimental grading of locally grown timber to be used as structural material. 2nd International Conference of Civil Engineering and Building Materials. 17-18 November 2012 Taylor and Francis Group, London (2013).

DOI: 10.1201/b13165-39

[5] UNI 11035-1. Visual strength grading for structural timbers. Part I: Terminology and measurements of features. (2010).

[6] UNI 11035-2. Visual strength grading for structural timbers. Part 2: Visual strength grading rules and characteristics values for structural timber population. (2010).

DOI: 10.3403/00560945

[7] UNI EN 384. Structural timber: determination of characteristic values of mechanical properties and density. (2010).

[8] UNI EN 408. Timber structures Structural timber and glued laminated timber. Determination of some physical and mechanical properties. (2010).

DOI: 10.3403/30159970

[9] UNI EN 14081-1. Strength graded structural timber with rectangular cross section. Part I: General Requirements. (2011).

DOI: 10.3403/30288843

[10] G. Schickhofer, M. Augustin. Final report: Project INTELLIWOOD – Working package 3 – Strength correspondence. (2001).

[11] G. Giordano. Tecnica delle costruzioni in legno 5th Edition. Milan, Italy: Ulrico Hoepli. (2010).

[12] M. Piazza, R. Tomasi, R. Modena. Strutture in legno. Materiale, calcolo e progetto secondo le nuove normative europee. Milan, Italy: Ulrico Hoepli. (2005).

[13] UNI EN 1310. Round and sawn timber. Method of measurements of features. (1999).

[14] X. Wang, F. Divos, C. Pilon, B. K. Brashaw, R. J. Ross, R. F. Pellerin. Assessment of decay in standing timber using stress wave timing nondestructive evaluation tools. A guide for use and interpretation. United States. Department of Agriculture – Forest Service. General Technical Report FPL−GTR−147. (2004).

DOI: 10.2737/fpl-gtr-147

[15] B. K. Brashaw, R. J. Vatalaro, J. P. Wacker, R. J. Ross. Condition assessment of timber bridges. 2. Evaluation of several stress-wave tools. United States. Department of Agriculture – Forest Service. General Technical Report FPL–GTR–160. (2005).

DOI: 10.2737/fpl-gtr-160

[16] B. Kasal, G. Lear, T. Tannert, Stress Wave, in: B. Kasal, T. Tannert (Eds. ), In Situ Assessment of Structural Timber: RILEM state of the art. Springer. New York, 2010, pp.5-24.

DOI: 10.1007/978-94-007-0560-9_2

[17] J. L. Sandoz. Moisture content and temperature effect on ultrasound timber grading. Wood Science and Technology. 27. (1993). 373-380.

DOI: 10.1007/bf00192223

[18] A. Hanhijärvi, A. Ranta-Maunus, G. Turk. Potential of strength grading of timber with combined measurement techniques - Report of the Combigrade project– phase 1. VTT Research Notes 568. ESPOO (2005).

[19] A. Hanhijärvi, A. Ranta-Maunus. Development of strength grading of timber using combined measurement techniques - Report of the Combigrade project– phase 2. VTT Research Notes 686. ESPOO (2008).