Estrutura de madeira para cobertura de aviários no Estado da Paraíba.

Abstract

The purposc of this study was to draw up a design for chicken shed roofing using the currcnt national and international standard, i.e., 12 meters width by 125 meters length. The design consists of a "Howe" typc woodcn truss structure used for three diffcrent types of building: a chicken shed with brick walls and artificial side ventilation, a shed with brick walls and natural ventilation (ventilation windows), and a shed with open walls (with end trusses) and longitudinal wind tunncl. The purpose of this work was also to characterize the "maçaranduba" (Manilkara sp., Sapotaceae) and "roxinho" {Peltogyne sp., Leguminosae) specics that are commcrcially available in the region. Several roofing structurcs were built in order to rcach a definition of the design, considering conditions of thermal comfort, such as the 4,20m height, interlocking tile roof, eat-west orientation, a 25 degree slanted roof, in addition to the rational use of wood. The wood was characterized using the simplified method of the Brazilian NBR 7190/1997 code. Truss structures were built using chords with 7,5cm x 12,5cm single transversal sections, diagonais with 7,5cm x 10,0cm single transversal sections, struts with 3,5cm x 12,5cm double sections, and purlins with 7,5cm x 15,0cm single transversal sections for the first and third chicken sheds. Structures with identical transversal sections for the chords, diagonais and struts, as well as side pieces with 7,5cm x 15,0cm transversal sections, 7,5cm x 15,0cm main purlins, and 7,5cm x 12,5cm end purlins werc built for the second shed. The three sheds had 2,72m spacing bctween trusses and 7,5cm x 12,5cm single transversal section bracing. The results obtaincd showed that these roofing structures allow for reduced consumption o f wood per square meter of roofing as well as lowcr costs. Moreover, the results of the wood characlcrization tests showed their classification to be C60.