In recent years, new solutions have been studied in order to intervene on existing buildings made of load-bearing masonry or reinforced concrete, both from the seismic point of view and the energy one. In recent years, novel modern techniques using lightweight steel profiles made of steel or aluminium alloys, suitably coupled with heat-insulating panels, have been proposed for requalification of existing building stock. In this paper, the Resisto 5.9 system designed by the Progetto Sisma S.r.l. company was studied and applied as a retrofit system of an existing masonry building. First, this new system for seismic energy requalification of the build-up was presented, describing the basic components and the mounting phases. Subsequently, it has applied to a case study building made of full-brick masonry located in the municipality of Casalecchio di Reno, on the outskirts of Bologna in Northern Italy. Finally, the used coating system was designed for the examined building together with other seismic interventions applied to horizontal structures and foundations. The seismic benefits deriving from using the proposed envelope system and other seismic interventions were proved from the seismic viewpoint by linear dynamic and non-linear static analyses using the TreMuri analysis software. From modal analysis it was seen that the dynamic behaviour of the building with Resisto 5.9 is improved, with an increase of the participating mass (68% instead of 49% of the bare building) of the second mode in the longitudinal direction. Moreover, from pushover analysis it was noticed that the seismic safety factor has passed from 0.51 to 1.05 in the X-direction and from 0.78 to 1.27 in the Y-direction. In conclusion, it was demonstrated that Resisto 5.9, together with all the other planned interventions, is able to accomplish the seismic retrofitting of the studied building.

Sustainability is of fundamental importance for the construction industry: in recent decades researchers focused on supplementing building components with multiple natural fibres, evaluating their mechanical performance and application fields. In this field, the common plasters are usually equipped with glass fibre mesh to avoid crack patterns due to shrinkage. Natural fibres, thanks to their high tensile resistance, can represent a green solution to solve this problem. In particular, this work investigates the properties and the mechanical characteristics of a biocompound obtained with hemp fibres. The first phase aims at identifying the ideal mixture between hemp fibres and mortar to improve workability and avoid altering the water/lime ratio. The performed physical tests provide useful information for the evaluation of the consistency and the workability of the compound. Based on these preliminary results, 10 combinations of 3 parameters, namely fibre diameter, percentage of hemp fibre in the mortar and length of the hemp braid fragments, are tested. Among the mechanical properties, bending, compressive and tensile behaviours are evaluated. For each test, the performances of fibre-reinforced samples are compared to reference specimens. From compressive tests it is noted that the best performances were obtained from fibres with diameter of 1 mm and length of 2 cm. On the other hand, from flexural tests, it is seen that braids with a length of 2 cm provide an average bending stress about 13% less than that of the control specimen. Contrarily, braids with a length of 3 cm give a mean increase of bending stress of about 8% compared to the control specimen.

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The management of plastic waste has become a fundamental issue in recent decades and several studies have focused on finding proper solutions to recycle and reuse these secondary raw materials in different sectors. Using plastic waste in the building sector allows for long-term application and reduces the number of times the recycling process is needed. This research focuses on experimenting with two building products, namely lightweight screed and concrete, with the addition of plastic waste in the form of irregular granules. The screed was produced by adding plastic granules of different sizes, while the concrete was produced by replacing different percentages of the coarse and fine aggregates with plastic granules and pulverized plastic. The screed has been tested under compressive and three-point bending tests, while the concrete has only been tested under compressive tests. The results have shown that the addition of plastic waste in both products led to the desired weight reduction. On one hand, plastic waste have provided a decrease in both tensile (−16%) and compressive (−25%) strengths of the screed with an increase of ultimate tensile strain (+60%). On the other hand, the only acceptable concrete mixture resulted to be the one with 25% of aggregates substitution, which exhibited a decrease in compressive strength (−40%) and an increase of ultimate strain (+38%), whereas samples with higher percentages of plastic aggregates have been not considered to be suitable as building materials.