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CONCRETE TECHNOLOGYwww.cpi-worldwide.com CPI %u2013 Concrete Plant International %u2013 2 | 2026Engineering, Land Management, Architecture and Mathematics (DICATAM) and some of its nationally and internationally renowned researchers in innovative building materials, such as Prof. Giovanni Plizzari and Luca Facconi.The second phase of the research project saw the introduction of an important innovation, in the form of Mapefibre ST 40 Plus synthetic macro-fibers supplied by Mapei and deployed both in the concrete mix used to make the slab in conjunction with the timber section, and in the concrete connectors that hold the two elements together. In fact, the research project included a campaign of experiments and various tests on a prototype modular slab made of pre-cast fibre-reinforced concrete panels, connected to a timber joist system by means of dry-fixing concrete connections. Why add fibers to concrete?Mapefibre ST 40 Plus fibers are used because they enhance certain properties of concrete, such as the post-cracking behaviour and the resistance to fatigue, providing the material with more ductility. All these aspects make it possible to reduce or eliminate the traditional steel reinforcements normally used in this type of building works.Adding fibers to concrete mixes boosts sustainability for many reasons: firstly, waste can be recovered and re-used in the production of these mixtures, making them %u201czero waste%u201d products. Unlike rebar, furthermore, fibers are added directly to the concrete mixture, thus considerably reducing the time and risk associated with the production, transportation and use of conventional reinforcement materials, while also cutting the time and cost of completing the work. What%u2019s more, in Modular Prefab Construction, the fibers help create a modular unit that can be reused at the end of the life-cycle of the structure it is incorporated into, thus promoting a circular economy in which waste materials are used for new construction projects, without any need to break up the concrete units to separate them from the rebar. What the tests showWith regard to the fibre-reinforced concrete connectors, the tests, carried out using a BRT machine and in line with the procedures set down in European Technical Standard Eurocode 5 and Appendix C of Technical Specification CEN/TS 19103, examined the maximum weight borne by the connectors, their local rigidity and their bending strength. The results clearly show that the maximum load, displacement and stiffness values are not affected by the presence of the fibres. In fact, they showed that the addition of fibers significantly increases the ductility of the connectors, which results in better distribution of shear forces among connectors, thus improving the behaviour of the precast modular slab.Finite element modelling was also used to study the behaviour of the structural element made with fibre-reinforced concrete, not only to simulate the static state but also to replicate the loads triggered by seismic action. The testers concluded