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PRECAST CONCRETE ELEMENTS204 CPI %u2013 Concrete Plant International %u2013 5 | 2025 www.cpi-worldwide.comThe precast concrete sector is moving towards materials and design solutions that combine high mechanical performance with reduced environmental impact. Macro synthetic fibres (MSF) have proven to be a reliable reinforcement option recognised by standards such as Model Code 2010, ACI 544.4R-18 and ACI 533R. Their use allows partial or total substitution of conventional steel reinforcement in applications such as fa%u00e7ade panels, pipes, manholes, tunnel lining segments or industrial flooring.In parallel, digital engineering is transforming how precast elements are conceived and verified. Tools such as CivilMapei, which integrates sectional analysis and FEM (finite element method) plate models, enable engineers to quantify the contribution of fibres to structural capacity both at ultimate and service limit states. The combination of innovative reinforcement materials with simulation-based validation offers an effective framework to produce durable, sustainable and cost-optimised precast elements.Industry context and challengesPrecast concrete is valued for its quality control, production efficiency and reduced site impact. However, manufacturers face increasing pressure to:%u2022 Reduce the CO2 footprint in line with corporate sustainability objectives and public procurement requirements.%u2022 Adapt to cements with lower clinker content and to aggregates of variable quality.%u2022 Maintain cost predictability despite fluctuations in steel prices and skilled labour availability.%u2022 Deliver more complex geometries and finishes while meeting tight production schedules.Macro synthetic fibres respond to these challenges by reducing or eliminating the need for secondary steel reinforcement, improving crack control without corrosion risks, simplifying production and enabling lighter sections when supported by testing and code provisions.Material technology and regulatory frameworkMacro synthetic fibres are manufactured from polyolefin-based polymers, with lengths typically between 40 and 60 mm and diameters above 0.3 mm. Their structural function lies in their ability to bridge cracks and provide residual tensile capacity, improving ductility and toughness.Key characteristics%u2022 Uniform distribution within the concrete matrix, reducing weak points.%u2022 Post-cracking behaviour defined by residual strength parameters (fR1, fR4 according to EN 14651).%u2022 Compatibility with a wide range of precast concretes, from SCC to dry-cast mixes.%u2022 Resistance to corrosion, making them suitable for aggressive environments.In Europe, the manufacture of polymer fibres for structural and non-structural concrete is regulated by EN 14889-2. Enhancing Precast Concrete with Macro Synthetic Fibres: Performance, Sustainability and Digital Design ToolsMapei S.p.A., Milano, Italyn Dr. Jos%u00e9 Mar%u00eda Vaquero and Dr. Carles Cots, Mapei, ItalyThe precast concrete sector is moving towards materials and design solutions that combine high mechanical performance with reduced environmental impact. Macro synthetic fibres (MSF) have proven to be a reliable reinforcement option recognised by various standards.