EXPERIMENTAL STUDY CONCERNING THE PHYSICAL PROPERTIES OF BLACK LOCUST WOOD (Robinia pseudacacia L.)

Mihaela POROJAN
Lecturer dr.eng. - Universitatea "Transilvania" din Brasov - Facultatea de Industria Lemnului
Adress: B-dul Eroilor nr.29, 500036 Brasov, Romania
Tel: +40 268 412921/int. 192. Fax: +40 268 415315.
E-mail: mporojan@unitbv.ro

Abstract: This paper presents the experimental results for the main physical properties of black locust wood from Romania, respectively: the moisture content in green state, the density at several values of moisture content, the total shrinkage and swelling coefficients and for 1% variation of moisture content in the cell wall. The experiments were carried out on black locust wood harvested from two different geographic regions of Romania, respectively North - the Carei region and South - the Arges region.
The following average values were obtained: for black locust from the North region the moisture content in green state was 35.11%, the oven-dry density was 664kg/m3, the radial, tangential and longitudinal shrinkage coefficients were 5.21%, 7.46%, and 0.21%, with a coefficient of anisotropy of 1.431 and the radial, tangential and longitudinal swelling coefficients were 4.70%, 7.30% and 0.19%. Close values, with no significant differences were obtained also for the black locust wood originating from the Southern region, respectively: the moisture content in green state was 36.42%, the oven-dry density was 651kg/m3, the radial, tangential and longitudinal shrinkage coefficients were 5.25%, 7.39% and 0.21%, with a coefficient of anisotropy of 1.407, and the radial, tangential and longitudinal swelling coefficients were 4.99%, 7.22% and 0.27%.

Key words: black locust, physical properties, moisture content, density, shrinkage, swelling, coefficient of anisotropy.

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*** SR ISO 4471-1993: Lemn. Prelevare de arbori de proba si busteni pentru determinarea proprietatilor fizice si mecanice ale lemnului din arborete omogene (Wood. Prelevation of Test Trees and Logs for the Determination of Physical and Mechanical Properties of Wood from Homogenous Growth Areas).
*** SR EN 13183-1-2003/AC:2004: Lemn. Continutul de umiditate al unei piese de cherestea. Determinarea prin metoda de uscare (Wood. Determination of Moisture Content of Timber. Oven-Dry Method).
*** STAS 84-87: Lemn. Determinarea masei volumice (Wood. Determination of Density).
*** STAS 85/1-91: Lemn. Determinarea umflarii (Wood. Determination of Swelling).
*** STAS 85/2-91: Lemn. Determinarea contragerii (Wood. Determination of Shrinkage).