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PRECAST CONCRETE ELEMENTS206 CPI %u2013 Concrete Plant International %u2013 5 | 2025 www.cpi-worldwide.comcalculates ultimate bending moment, crack widths under service loads and interaction diagrams for combined bending and axial force.For elements such as large panels, stairs or precast slabs, the FEM plate module evaluates critical bending and shear demands for each load case. After accounting for the structural contribution of the fibres, it determines the required quantities of conventional steel reinforcement (cm%u00b2/m) to be added to the fibre content, resulting in an optimised reinforcement layout.Applications in precast concreteFa%u00e7ade panels: In thin wythes susceptible to shrinkage and thermal cracking, dosages of 2.4 - 3.0 kg/m%u00b3 have replaced secondary mesh, improving surface quality and production speed.Segmental tunnel linings: Hybrid reinforcement combining primary bars with 5 - 6 kg/m%u00b3 of MSF reduces congestion, improves compaction and extends service life, particularly in aggressive environments.Industrial floor slabs: In high-load applications, high-dosage MSF has replaced welded mesh, reducing installation times, improving safety and ensuring controlled crack widths.Complex geometries: In elements with intricate shapes, fibres provide uniform reinforcement where bar placement would be difficult or uneconomical.Sustainability impactConsidering the CO2 emissions values declared in the report the Macro Synthetic Fibre Association (MSFA) in 2023, the quantified the embodied carbon of different reinforcement types of reinforcement: %u2022 Steel rebar: 0.84 kg CO2 eq/kg%u2022 Steel fibre: 1.58 kg CO2 eq/kg%u2022 PP macro fibre: 2.25 kg CO2 eq/kgThe reduction in embodied CO2 can reach approximately up to 60% (depending on the precast element) compared with steel reinforcement, an important advantage for projects seeking environmental certification or net-zero targets.Practical considerations and scopeFrom a production standpoint, fibres should be added gradually to ensure dispersion, adjusting PCE superplasticisers to maintain workability. They are compatible with SCC and vibration-cast concretes, and surface visibility can be minimised through correct mix design and compaction. Residual strength testing should be part of quality control.The scope of MSF is defined by several considerations:%u2022 They do not replace primary longitudinal reinforcement in beams or columns where ductility depends on continuous bars.%u2022 Products must comply with EN 14889-2 and be validated by recognised testing standards.%u2022 Their behaviour under accidental actions such as fire or high temperature must be verified according to EN 1992-1-2, with protective measures where necessary.These are design boundaries rather than limitations to their use; in many non-prestressed and crack-control-driven applications, fibres can fully or partially replace traditional reinforcement while maintaining safety and durability.OutlookThe combination of advanced reinforcement materials and digital design tools will continue to shape precast concrete. As design codes integrate fibre reinforcement more explicitly, the use of CivilMapei and similar platforms will be essential to quantify contributions, avoid over-reinforcement and demonstrate compliance with both structural and sustainability criteria.Integration with BIM and automation in production will further enhance efficiency, allowing optimised, low-carbon precast solutions that meet both technical and environmental demands. nFURTHER INFORMATIONMapei SpAVia Valtellina 6320159 Milano, Italymapei@mapei.itwww.mapei.itCPi Newsletter CPi ePaper ICCX Newsletterwww.cpi-worldwide.com