INFLUENCE OF TEMPERATURE AND MOISTURE CONTENT ON NON-DESTRUCTIVE MEASUREMENTS IN SCOTS PINE WOOD

In the present study, non-destructive parameters and mechanical properties have been measured on the principal structural Spanish sawn timber species, Scots pine (Pinus sylvestris L.). Non-destructive testing and three-point bending tests according to DIN 52-186 1978 were conducted on 216 specimens. Specimens were studied at six different temperatures and four different equilibrium moisture contents. The non-destructive testing techniques applied were: ultrasonic wave technique (Sylvatest Duo and Steinkamp BPV) and vibration analysis technique (Grindo Sonic Mk5"Industrial"). Differences in mechanical properties between samples with different temperatures (from 40 to 50 degrees C) and equilibrium moisture contents (from 10 to 18 %) were studied. Linear tendencies between nondestructive testing and mechanical properties with respect to equilibrium moisture content were obtained. However, two different tendencies (above and below 0 degrees C) were found with respect to temperature. In addition, adjustment factors are proposed for every variable.