Fast-growing woods for use as a railway sleeper.

The main mode of transport in Brazil is the road; however, the railroad has a freight rate 39% lower, which demonstrates its economic potential. Railroad ties are essential in railroads, and for many years, native wood was used as raw material. For environmental and economic reasons, it is important to identify reforested wood species with fast growth that may be used as ties. Thus, the present study aimed to evaluate the quality of Eucalyptus dunnii, Eucalyptus grandis, Eucalyptus saligna, and Corymbia maculata woods for use as railway sleepers according to the NBR 7511 standard (ABNT, 2013) and compare them with the material inspection procedure PIM 14 (2016) of the National Department of Transportation Infrastructure (DNIT). It was observed that the wood of the species C. maculata presented the closest conditions for use as ties, probably due to its high density, which is directly reflected in the specific mass and mechanical properties of hardness and shear. However, this species showed less dimensional stability, due precisely to its high density and thus larger cell wall diameters. Successive to the good performance of C. maculata, the E. saligna was the second species that was best fit for use as ties, but it was not classified for two properties: traction and the sum of the properties: (B) hardness in MPa, (C) shear resistance in MPa, (D) normal strength resistance in MPa, (E) fracture toughness in MPa, respectively B + C + D + E. Nevertheless, it is the one that best presents dimensional stability. The other woods did not meet the minimum levels for use as ties. [ABSTRACT FROM AUTHOR]