Perdas de madeira na execução do sistema de fôrmas para concreto em obras de construção civil

Abstract

Because it is a highly versatile and inexpensive material compared to other inputs, timber is widely used in the construction industry for a variety of functions. In Brazil, however, there are few studies relating the losses of timber within the building sites. The present work consists of the analysis of the losses of timber in the production and use of the system of concrete forms, aiming to increase the knowledge about losses of material in the civil construction and searching for methods to enhance the process performance. For that, three civil works were analyzed in the city of São Lourenço do Oeste, Santa Catarina, Brazil. A review is first presented on losses in civil construction and on the production process of the forms. Next, the percentages of losses in each civil work, based on the differentiation of the quantities of timber defined in project and cost estimating, are calculated from those actually used in the development of the works, checked through the purchase notes of the projects. At the end of the study, an average increase of 11.82% in the cost of timber inputs was obtained due to the losses in the production of formwork. The inputs that presented the highest loss rates were the boards and plywood sheets. The main responsible for the loss of timber in the analyzed works were the high number of use considered for the inputs, and the lack of organization and separation of the same ones in the construction site.