The technology of the Construction Industry is advancing constantly. Every year, new materials, equipment, and building techniques are introduced. In the specific case of reinforced and pre-stressed concrete structures, the innovations have contributed to the improvement of the properties of the concrete and the durability of the structures that incorporate this material. These advances are not restricted to the construction of new structures, however, and it is important to recognize the need to recuperate structural elements or increase their resistance, which has provided incentives for the improvement of techniques of structural reinforcement. In this context, the present study used a combined theoretical and experimental approach for the investigation of the effectiveness of the reinforcement of concrete columns by jacketing them with polymer mantles strengthened with carbon fibers. The analyses aimed to determine the effectiveness of the mantles in terms of the increase in resistance to axial compression and contribute to the understanding of the structural behavior of columns strengthened using this technique. To this end, centered axial compression tests were run on five short reinforced concrete columns, including one control column and four experimental columns with different reinforcement ratios. Numerical simulations were also run in the Abaqus software to determine the distribution of tensions inside the columns. The sum of the evidence was analyzed and it was verified that the strengthening used in the columns increased considerably their resistant capacities, thus the gain in this capacity was directly proportional to the value of the used strengthening rate-the column with the biggest strengthening rate bore a last load 42.8 % bigger than the one borne by the column of reference, with no strengthening. From these data, it was possible to obtain a simple predictive model of the increase in resistance capacity of columns strengthened with carbon fibers.

From the implementation of analytical solutions for thin rectangular slabs using the Finite Difference Method, the present paper was developed with the purpose of comparing the determined efforts in a concrete plate with those that would be found using the tables originated from the plates theory of authors established in the literature. For this, the programming language Python was used, taking as a case study, a slab with dimensions of 5 meters long by 3 meters wide and thickness equal to 0.10 meters. In the analysis of the efforts, several support conditions were considered, in which the internal efforts and displacements obtained by the Finite Difference Method were compared with the results obtained through the tables proposed in literature. It was verified that the Finite Difference Method constitutes a good alternative for the resolution of thin solid plates, since the results were similar to the classic solution proposed in literature. The implemented program allows the visualization of the efforts through of spectrums of zone which facilitates the understanding of the distribution of the efforts along the slab, differing slightly from the uniform distribution adopted in the tables consulted.

Este artigo aborda temas vivenciados dentro de sala de aula, no contexto da diversidade cultural no Ensino de Ciências, para tanto fez-se necessário o embasamento em estudos realizados nas mais diversas localidades. Diversidade cultural, ensino de Ciências e formação de professores são contextos que se interligam e que são pautados nos documentos direcionadores da educação brasileira, mas tratados com superficialidade quando observados na realidade de cada Sistema de Educação. Com a intenção de discutir e propor uma forma de contextualização dos temas, em sala de aula, o presente estudo traz as seguintes problematizações: Como ensinar Ciências por meio da Diversidade cultural presente em sala de aula, na contextualização do multiculturalismo? Metodologicamente, há uma pesquisa bibliográfica, exploratória, de abordagem qualitativa,  associada a um estudo de caso, por meio de uma contextualização da Diversidade cultural dos estudantes de Formoso do Araguaia-TO, oriundos de zona rural, povos indígenas e zona urbana no mesmo ambiente escolar, e a vinculação com o ensino de Ciências, por meio de formação de professores. Contudo, vale ressaltar que a formação continuada é uma proposta de construção de saberes no contexto da realidade local.  E assim tendo como ressultado a garantia dos direitos  dos estudantes a uma aprendizagem significativa e contextualizada no Ensino de Ciencias.

No abstract

This work was aimed at analyzing the efficiency of the strengthening of reinforced concrete beams with the addition of steel bars and epoxy adhesive. Five beams were produced, out of which four beams were strengthened to flexure. In two of them, “U” clips were also used to improve the anchorage of the strengthening. The tests demonstrated that the clips reduced the resistances of the beams compared to those without clips. The strengthened beams without clips yielded better results, but the largest limiting factor was the adherence between the epoxy and beam. The use of clips for solving the problem of adherence made this research original. The conclusions were based on the comparisons of the tested beams.