Relationship between shear strength and compressive strength parallel to grains of hardwoods

Abstract In Brazil, the standard NBR 7190: 1997 establishes testing methods to determine the physical and mechanical properties of the material. However, the tests require that the procedures be undertaken in specialised, high-cost laboratories. The Brazilian code sets different values for relations between shear strength and compression strength parallel to the grain. The aim of this study was to investigate the relation between compressive strength and shear strength parallel to the grain, considering the results of the tests of those properties. The results were compared with the relation values set by the Brazilian Standard NBR 7190:1997, and the optimal coefficient found was 86.4% higher than the coefficient set by the Brazilian standard, considering the set of all species. With regards to the variation in the relation between the investigated properties, considering the different classes of wood resistance in this study, no decreases were found in the values of the optimal coefficients as the classes increase (a situation described in the NBR 7190:1997 standard), which represent one further divergent result.