Deformability of base connections in shotcreted concrete sandwich load bearing perforated walls

Fast construction of structural walls made of reinforced concrete for buildings or industrial warehouses in single panel is a cost-effective system in terms of both the quality of construction and the economy. Anti-seismic constructions can be built with additional reduction of heat dispersion and noise attenuation. In this study the structural system is composed of a factory produced corrugated panel of polystyrene covered on both sides by an electro-welded zinc coated mesh of galvanized steel and shotcreted concrete poured to build the vertical structural walls. This system allows economic savings compared to the traditional systems; however, deformability of the base connections can alter significantly the structural behaviour and seismic response. This study deals with both experimental tests on a real scale structure and numerical simulations, with the goal to provide an efficient formulation to model the deformability of base connections in such sandwich concrete structures, while the materials are modelled either linear elastic or nonlinear

Effect of fiber-to-matrix bond on the performance of inorganic matrix composites

The strengthening of masonry structures is nowadays performed by means of high-strength fibers embedded in inorganic matrix (FRCM) where lime or cement-based matrix is used instead of epoxy adhesive to reduce debonding issues between substrate and matrix. However, some sliding phenomena and cohesive failures between fibers and the matrix mortar can occur. The paper examines the effect on the FRCM efficiency of the mechanical properties of fiber and matrix and potential geometrical defects, which are possible in real field applications or in qualification tests. The model application to simulate bond tests on typical PBO-FRCM and Glass-FRCM allowed to analyse slips as well as normal and shear stresses both in the bundle and in the matrix constituting the FRCM, for different defects due to application issues. The result of numerical simulations seems to interpret well the results of the qualification tests with a multi-bundle effect that justifies their scatter. The approach can be applied by varying main mechanical properties of the materials (e.g. elastic modulus, fiber cross section, bond properties) to consider their intrinsic variability in the assessment of the performance of the FRCM system or by changing the type of materials (i.e. mortar and fibre) to optimize the FRCM system