Evaluation of bond strength between the concrete and Bambusa vulgaris bamboo available in Ilha Solteira

Abstract

The environmental changes that are occuring on our planet, due to mainly because of the overuse of natural resources that are not renewable, is forcing the human being to search for new sustainable materials. According to many researchers, bamboo is a typically, tropical, perennial and renewable plant. It is therefore an appropriate source of raw material whose extraction do not hurts the environment and a material that can be used in civil construction due to its good mechanical properties. However, as a consequence of being an organic and hygroscopic material, bamboo has a wide variation in its strength, and, when combined with concrete, it has the disadvantage of absorbing fresh concrete´s water, which can provoke cracks; after the time of curing, with the concrete already hardened, the bamboo starts to dry and lowers its volume, which can harm its bond to the concrete. Thus, waterproofing technics have been studied in order to be used on bamboo, to decrease its water absorption. Besides being necessary the use of superficial waterproofing treatments on bamboo, it is also necessary to know the maximum bond stress that can exist between concrete and bamboo, so that it can be used as a tensile element than can partially or fully replace the steel in structures of reinforced concrete. The aim of this work is to obtain the bond stress between concrete and the Bambusa vulgaris bamboo, available in the city of Ilha Solteira, using pullout tests. These tests represent the behavior of the bamboo as being a tensile reinforcement element in a reinforced concrete structure. It will be used specimens with a waterproffing surface treatment, without and with steel pins whose function will be to improve the bond between the materials. In future, the parameters obtained by this research could be used in the study of slabs with lattice reinforcement, where the bamboo could be used as a tensile element, supplementary to the lattice reinforcement, in order to increase the strength and the stiffness of the slab.