Joao Ricardo Masuero

Análise da espessura do cobrimento de armadura em lajes com diferentes distanciamentos entre espaçadores e pontos de amarração

Resumo Given that the durability of structures is directly related to the thickness of the cover to reinforcement, it is essential to ensure minimum cover is achieved when building a structure. However, studies show that this is not always the case. One of the reasons for the this problem is the lack of indication, in structural projects, of the positioning of spacers. This situation is compounded by the lack of standards and regulations on the use of spacers (i.e. minimum quantities and required layout). This study assesses three different spacer distances and two different tying distances in order to examine the influence of these factors in the cover to reinforcement. To achieve so, three slabs were prepared in situ using different arrangements. After demoulding, cover thickness was determined using a digital covermeter. It was observed that the factors investigated have a significant influence in the final cover.

Proposta de elemento de integração para a interface entre alvenaria estrutural e esquadria

A utilizacao de sistemas modulares na industria da construcao tem crescido de forma acentuada nos ultimos anos no Brasil, sendo que, dentre estes, se destaca o sistema construtivo de alvenaria estrutural. Entretanto, diversos estudos apontam uma alta incidencia de manifestacoes patologicas relacionadas a este sistema. A interface entre alvenaria e esquadria e um dos locais de maior incidencia de problemas, alem de representar um gargalo construtivo, pela necessidade de realizacao de inumeras atividades que dependentes da mesma. O presente artigo apresenta o processo de desenvolvimento de uma nova solucao para este problema, denominada elemento de integracao, incluindo sua definicao geometrica, funcional e conceitual, bem como a producao de prototipos virtuais e fisicos (com diferentes materiais). Ao longo do desenvolvimento de diferentes modelos, foram realizadas avaliacoes pela equipe de projeto, a partir das quais foram introduzidas melhorias. Ao todo, foram produzidos 4 modelos virtuais, 3 modelos fisicos na escala 1:1, e uma parede experimental. Os principais resultados apontam para a viabilidade e adequacao da proposta ao sistema construtivo, bem como identificam o possivel aumento de construtibilidade do sistema como um todo a partir da aplicacao do elemento desenvolvido.

Avaliação de desempenho de espaçadores plásticos : proposição e avanço de métodos de avaliação

The durability of reinforced concrete structures is highly dependent on the characteristics of the concrete cover to reinforcement and its thickness. The failure to obtain cover thickness is the factor with the largest influence on the premature corrosion of the reinforcement, which in turn is the main deterioration form of reinforced concrete structures. Studies indicate that the designed cover is not reached in the current constructions that adopt this structural solution, configuring a chronic, and not a sporadic problem. One of the observed causes for the failure in obtaining the minimum standardized cover is the incorrect use of spacers and the use of inadequate spacers. This is made more serious by the absence of a Brazilian standard to regulate the product and its use and, consequently, the absence of a quality certification from the responsible regulating agency. Focusing on spacers, requirements and performance criteria were proposed, in addition to methods for their assessment, with most being taken and adapted from international standards. Subsequently, some spacers available on the market were effectively tested according to the proposed methodology. No spacer model proved to be satisfactory according to the established performance approach. However, for each criteria and assessment methods proposed, there was, at least, one spacer model at the market which satisfied them, so it can be said that the criteria and methods are suitable for spacers performance evaluation. Faced with the performance diversity of the spacer models on offer, the need for a regulatory Brazilian standard for this product was confirmed in order to delimit the quality of spacers available on the market and to eliminate this variable as one of the causes for not obtaining the correct covering.