Homologación de madera blanda y semiduras de latifolias para su uso como encofrados

Abstract

The wood use to timbering exists in Cuba like one of the first options to solve the problem of the concrete foundry in situ in the construc tions with different objectives. Traditionally it has been used with this objective the conifer ones autochthonous and imported assisting to their good physicalmechanical and technological characteristics and due to their biggest abundance, being the predominant species in the forests of the north hemisphere and being in big extensions of plantations and natural forests of the south hemisphere. In the last years in Cuba has shown remarkable increments of the constructive activity endorsed by the national interest of building 100 000 annual housings, that which demands high wooden volumes with different uses. The objective of the work is to generalize inside the pitch of wooden species feasible of being used in the construction, some broad leaf species ones soft present in the Cuban forests, that which would allow to increase the readiness of this important constructive material. The species selected are Sterculia apetala (Jacq.) Karst. (anacahuita), Bursera simaruba (L.) Sargent (almácigo), Cecropia peltata L.  (yagruma), Spondias monbin L. (jobo), Samanea saman (Jacq.) Merril. (domestic locust) and Erythrina peoppigiana (Walp.), A. F. Cook (búcare). The normal density was determined to 12% of humidity of the wood. Equally the static bending is calculated using the norm ISO 3133 with specimens of 2 x 2 cm of traverse section and 30 cm of long. The obtained results allow to contain to the species studied in Pino Macho, group 1 (almácigo, algarrobo y jobo), group 2 (anacahuita, yagruma and búcare). Is defined that the species softwood resistance drops in value to bending , is propoused to reduce the space among all the component elements of the timbering, included the props, in 66% for the species considered in the group 2, and in 50% for those of the group 1.