Estudo experimental de conectores de cisalhamento em chapa xadrez discretos

Abstract

The use of composite steel-concrete structures is already well established in several applications. However, the scarcity and relevance of works that address new alternatives of linear shear connectors added to other resistant mechanisms or even to new dispositions and geometries that contemplate the most widespread construction models in the country. This work experimentally evaluated a new alternative of discrete linear shear connectors formed by sheets with checkered grooves through a systematic review and experimental program. The systematic review captured 2976 works in the Scopus database, of which, after the application of several filters of relevance and adequacy, 18 works composed a meta-analysis about the linear connections of shear in composite structures. As a result, despite the heterogeneity of the data, satisfactory strength profile and ductile behavior were shown, with 563 kN, 1808 kN/m, 511 kN, 9.73 mm, and 2.13 being the medians for strength per connector, per meter, by dowel, ductility capacity and slip coefficient, respectively. Correlation and variance analyses exposed the influence of several parameters on the behavior of linear connectors, with emphasis on the impact of thickness, hole shape, and reinforcement on the strength and ductility of the models. In the end, it was possible to build regression models for the study of resistances of linear connectors, with the adjusted coefficient of determination (R²) of superiors and 0.96 and standard errors in the order of 140 kN being considered satisfactory. Furthermore, an experimental practice was carried out through shear tests of the Push-out type, evaluating the typology of the slabs and the addition of resistant mechanisms. The tests showed that the proposed connectors presented a good structural behavior, presenting average shear strengths of 484.80 kN, 468.60 kN, and 212.95 kN, respectively, for the MAC-X, TRE-X and MAC-L models. The connectors presented ductility within the normative standards. Regarding the kinematic law, prototypes presented perforated models and adhesion characteristics. Ultimately, the lattice slabs proved to be more susceptible to cracking patterns than the models with solid slabs, and this is due to their low reinforcement ratio.