Influência do tempo e da temperatura sobre as propriedades físico-mecânicas da madeira de Pinus sp.

Abstract

The Pinus genus groups more than 100 species. In Brazil, Pinus has been planted in the country, initially for ornamental purposes, and since 1950 with production on a commercial scale to supply the wood supply, having great use in civil construction. The wood is questioned about its own use in civil construction, especially with regard to fire, as it is a combustible material to end up substituted with other materials such as iron and steel. In this way, the objective of this work is to determine the reduction of the mechanical resistance of Pinus sp. When subjected to different temperatures, being 100, 250 and 500 ° C with different exposure times, 15, 30 and 45 minutes for each temperature. At a temperature of 100 ° C, the longer the exposure time, the higher the values obtained from the maximum stress in parallel compression tests such as fibers. A greater attempt was obtained by the treatment 250 ° C (15min), but decreasing as the time increased, due to the breakdown of chemical bonds. The behavior of the compressive strength is inversely proportional to the time of exposure, higher values are verified in larger times. The reduction of the transverse area is related to the increase in temperature and time.