C. Fernández-Rodríguez’s research while affiliated with University of Santiago de Compostela and other places

The objective of this paper was to detect pith location in chestnut lumber by using acoustic tomography techniques. To this end, the velocity gradient was analysed by relating the value of longitudinal stress-wave velocity to the distance from the point where velocity was measured to the pith. A commercial stress-wave timer was used to measure longitudinal stress-wave velocity in 100aEuro-xaEuro-200aEuro-xaEuro-400 mm(3) pieces of chestnut lumber (Castanea sativa Mill.) obtained from mature trees. The analysed pieces were conditioned to 20% moisture content. Results were classified according to the distance from the point at which velocity was measured to the pith. ANOVA revealed significant differences for mean velocity between the values obtained nearest the pith (at less than 40.0 mm) and the values obtained farthest from the pith. Velocity increased with distance to pith. The coefficient of determination for the linear regression between both variables was R(2)=0.96. The results of the tests showed a statistically significant relationship between longitudinal velocity and distance to pith. Such results allowed for the estimation of pith location in the area with the lowest velocity values.

This paper aims to determine the factors that most strongly influence the durability of timber members in agricultural and livestock buildings. A sample of 133 agricultural and livestock buildings was selected, including barns for housing different livestock species and other agricultural buildings such as storage buildings or hay barns. Every building was inspected in order to gather information about the timber structure. The following variables were analysed: timber species, service life of the structure, features, treatment, structural condition, type of product (round or sawn timber), structural system, joint design and service conditions (end use of the building, environmental conditions, ventilation). Timber durability was assessed based on the structural condition of the buildings, and the influence of the other variables on the condition of the structure was analysed. Data analysis revealed that the structural condition of the buildings studied was not affected by age or species. The factors with the strongest influence on the structural condition of the buildings were wood treatment, ventilation and the proper design of joints between timber members. Therefore, the durability of timber structures in the buildings studied was dependent on the construction practice, including the previous treatment of wood and the proper maintenance of the structure (ventilation, cleaning).