Twenty years of research
at EPFL
ConcrIT is the commercial suite of EPFL’s IBETON academic tools. A look back at the researchers, the JCONC solver and the i-concrete platform that made stress fields a world-reference method.
From EPFL to ConcrIT
ConcrIT is the commercial suite of the academic tools developed at EPFL’s Structural Concrete Laboratory (IBETON). Since 2005, the i-concrete platform and its solver JCONC have enabled thousands of engineers and students to master stress fields. More than ten doctoral theses have validated and extended the implemented methods.
Doctor of ETH Zurich (1989), full professor at EPFL since 2000. At IBETON he founded the research programme on elastic-plastic stress fields. Author of Design of Concrete Structures with Stress Fields (1996) and Compatible Stress Field Design of Structural Concrete (2020). His work constitutes the scientific foundation of ConcrIT.
SCIENTIFIC DIRECTOR
Senior researcher at IBETON, he is the main developer of JCONC (2005), the elastic-plastic stress field (EPSF) solver distributed via the i-concrete platform. His work laid the theoretical and numerical foundations of the method. Key publication: On Development of Suitable Stress Fields for Structural Concrete (ACI Structural Journal, 2007). Today a Professor at the Universidad Politécnica de Madrid.
JCONC CREATOR
Senior scientist and lecturer at IBETON for 34 years. He made significant improvements to the JCONC solver and developed and maintained the laboratory’s online educational tools, including the i-structures platform. Co-author of Dimensionnement des structures en béton (2004). Guarantor of the link between IBETON research and professional practice and of the upkeep of the digital tools.
WEB TOOLS DEVELOPERDoctoral researchers who validated and extended the method
Each of these theses used stress fields (via JCONC / EPSF) to analyze and experimentally validate the behaviour of reinforced concrete structures in increasingly complex configurations.
Reinforced concrete members subjected to a combination of bending, shear and deviation forces. Use of EPSF to analyze different transverse reinforcement configurations and define the minimums required for satisfactory strength and ductility.
EPSF · bending + shear
Research on rigid-plastic stress fields (RPSF) for checking critical details in existing structures. Co-author of How simple can nonlinear finite element modelling be for structural concrete? (2014), demonstrating the accessibility of the EPSF approach for engineers.
RPSF · existing structures
Querkraftwiderstand von Stahlbeton- und Spannbetonträgern mittels Spannungsfeldern. Shear resistance of reinforced and prestressed concrete beams using stress fields. Appendix A is entirely dedicated to validating the EPSF-FE method against experimental tests.
EPSF · reinforced & prestressed beamsStress fields for the interaction of in-plane and out-of-plane forces in reinforced concrete shell elements. Extension of the EPSF method to shell elements subjected to combinations of in-plane and out-of-plane forces — opening the way to complex spatial structures.
EPSF · shell elements
Development of a consistent approach for design and assessment of structural concrete members using stress fields and strut-and-tie models. Creation of an EPSF database validating the method against 315 experimental tests (mean predicted/measured strength ratio: 1.03).
EPSF · 315 tests validatedResearch stay at IBETON during his PhD at the Polytechnic University of Valencia. Work on elastic-plastic stress fields for complex structural configurations. Today a senior researcher at the Structural Concrete Laboratory of ETH Zurich (Prof. Kaufmann).
EPSF · complex configurationsOn the compressive and bond strength of reinforced concrete as structural properties. Stress field study of the influence of concrete placement phenomena on structural strength and bond — with direct impact on ConcrIT’s strength reduction factors.
EPSF · concrete strength & bondWork on modelling the compressive strength of concrete and mechanical uncertainties. Co-author of Concrete compressive strength: from material characterization to a structural value (Structural Concrete, 2021), a key publication for calibrating strength factors in EPSF methods.
EPSF · compressive strengthBuilding on more than 20 years of research at IBETON and the validation of the method on hundreds of experimental tests, ConcrIT takes up the scientific foundations of JCONC and i-concrete and integrates them into a modern, fully online professional environment. Following the closure of IBETON in 2024, ConcrIT continues and extends this legacy. The stress field approach guarantees consistent, safe and economical results for the design and assessment of reinforced concrete structures, in accordance with the SIA 262 and Eurocode 2 standards.