TY - JOUR AU - Arriaga, F. AU - Esteban, M. AU - Relea, E. PY - 2005/12/30 Y2 - 2024/03/29 TI - Evaluation of the load carrying capacity of large cross section coniferous timber in standing structures JF - Materiales de Construcción JA - Mater. constr. VL - 55 IS - 280 SE - Research Articles DO - 10.3989/mc.2005.v55.i280.205 UR - https://materconstrucc.revistas.csic.es/index.php/materconstrucc/article/view/205 SP - 43-52 AB - A total of 85 large section timber pieces (Pinus sylvestris L. and Pinus pinaster Alt.) found in a number of old buildings were visually analyzed and graded pursuant to Spanish standard UNE 56544 and German standard 4074. The object was to formulate a non-destructive method to reliably and effectively determine the mechanical properties of existing timber structures with large cross sections. A new system is proposed based on the chief visual grading parameters and consisting in a single grade; the percentage of rejections with this system is low. In this regard, a specific strength class is established for large cross section members in existing coniferous wood structures, namely F14/E9/D380 (MOR of 14 N/mm<sup>2</sup>, MOE of 9 kN/mm<sup>2</sup> and characteristic density of 380 kg/m<sup>3</sup>). The use of ultrasonic velocity is proposed to define the next higher strength class - F16/E10/D380, to which timber with velocities of 4,900 m/s or over would be assigned. ER -