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CONCRETE TECHNOLOGYwww.cpi-worldwide.com CPI %u2013 Concrete Plant International %u2013 4 | 2025 63tility and design flexibility. The Eurocode system and related EN Standards provide a clear framework for the mechanical characterization and specification of FRC in structural applications.Standard tests for FRC characterization:%u2022 EN 14651: Flexural tensile strength on notched beams (150 %u00d7 150 %u00d7 550mm), providing fLOP and residual strengths fR1 to fR4.%u2022 EN 14889-2(6): Specifies synthetic fibre properties (tensile strength, geometry, anchorage, durability).5.2. Constitutive criteria for FRC design based on standard testsDesigning structural elements in fibre-reinforced concrete requires the definition of constitutive models based on residual flexural strengths obtained from standard tests such as EN 14651. These models allow translation of material behaviour into simplified mechanical laws suitable for numerical analysis.Types of constitutive models:%u2022 Rigid-plastic (simplified) model:%u2022 used for ULS design%u2022 assumes constant post-crack strength: fFtu = (1/3) %u00b7 fR,3%u2022 moment resistance: MRd = (fFtu %u00b7 b %u00b7 h%u00b2) / 6%u2022 no iteration required; suitable for ductility classes a%u2013c%u2022 Multi-linear (bilinear) model:%u2022 used for refined ULS and SLS verification%u2022 two linear branches derived from:%u2022 fFt,1 = %u03ba %u00b7 0.37 %u00b7 fR,1k%u2022 fFt,2 = %u03ba %u00b7 (0.57 %u00b7 fR,3k %u2013 0.26 %u00b7 fR,1k)%u2022 strains computed from CMOD and geometry%u2022 requires iterative solution for internal equilibrium and moment%u2013curvature response.6. Structural validation and performance analysisThe CivilMapei design engine performs both ultimate and serviceability verifications, including:%u2022 flexural resistance (MRd vs MEd)%u2022 shear strength including fibre contribution (VRf)%u2022 crack width checks per Eurocode 2%u2022 moment%u2013curvature analysis to evaluate ductility.The 2D plate module in CivilMapei models support conditions, voids, openings and irregular load cases. Outputs include shear and bending moment maps, crack patterns and required reinforcement contours. For pavements, load cases from racks, forklifts and trucks are addressed and fibre dosage is calibrated accordingly.7. Example of application: Precast cabin panelA practical case involved the optimization of a precast concrete cabin using MSFRC. The fibre-reinforced mix allowed for a significant reduction in conventional steel fabric, improving production efficiency and reducing labor. Finite-element analysis performed using CivilMapei verified the post-cracking stress capacity and supported early demolding, critical in precast workflows. Additional design modules were used to evaluate thermal effects and simulate handling stresses during transport and installation. The design process ensured compliance with structural performance and durability requirements.8. Concluding remarksMacro-synthetic fibre-reinforced concrete offers a robust and sustainable alternative to traditional steel reinforcement. It allows for innovative and efficient solutions across a range of applications, from modular construction and infrastructure to precast utilities and industrial pavements.The integration of CivilMapei, an advanced structural design software, enables engineers to exploit the full potential of MSFRC by simulating post-cracking behaviour, validating residual strengths and streamlining structural verification. By aligning with Eurocode and fib Model Code Standards, the software supports consistent and safe implementation of FRC systems.As standardization and field data increase, the broader adoption of MSFRC in structural design is expected to grow, contributing to a more resilient and low-carbon construction sector. nReferences1. British Standard Institution, BS EN 1992-1-1. Eurocode 2. Design of concrete structures - General rules and rules for buildings, bridges and civil engineering structures. BSI, London, 2023.2. F%u00e9d%u00e9ration Internationale du B%u00e9ton. The fib Model Code for Concrete Structures (2020). fib, Lausanne, Switzerland, 2024.3. Concrete Society. Concrete industrial ground floors. A guide to design and construction. Technical Report 34, Fourth Edition, Camberley, January 2018.4. F%u00e9d%u00e9ration Internationale du B%u00e9ton. fib Model Code for Concrete Structures 2010. fib, Lausanne, Switzerland, 2013.5. British Standard Institution, BS EN 14651. Test method for metallic fibre concrete. Measuring the flexural tensile strength (limit of proportionality (LOP), residual). BSI, London, 2005+A1:2007.6. British Standard Institution, BS EN 14889. Fibres for concrete. Part 2 %u2013 Polymer fibres. Definitions, specifications and conformity. BSI, London, 2006.FURTHER INFORMATIONMapei SpAVia Valtellina 63, 20159 Milano, Italymapei@mapei.itwww.mapei.com