Periodic Reporting for period 1 - ZeroNegCon (Development of Zero-Clinker, Negative-CO2 Concrete from the Atomic Scale)
Période du rapport: 2025-06-01 au 2027-05-31
Résumé du contexte et des objectifs généraux du projet
The construction sector is one of the largest contributors to global carbon emissions, with ordinary Portland cement responsible for a substantial share of industrial CO2 release. Cement production relies on energy-intensive clinker manufacturing and limestone calcination, which together generate unavoidable process emissions. At the same time, rapid urbanisation and infrastructure renewal are increasing the demand for concrete, creating a pressing need for low-carbon and scalable alternatives that do not compromise performance, durability, or safety. Within the European Green Deal and climate-neutrality targets, developing next-generation construction materials that can both reduce emissions and actively store carbon is a strategic priority for climate mitigation, resource efficiency, and industrial transformation.
This project addresses this challenge by developing a new class of zero-clinker, negative-CO2 concrete. The core idea is to replace conventional clinker-based binders with alternative mineral systems that can be synthesised at lower temperatures and designed to actively capture and mineralise CO2 during curing and service life. By integrating carbon into the material itself, concrete can shift from being a major carbon source to becoming part of the climate solution. This approach directly responds to the need for scalable, durable, and economically viable low-carbon construction materials that fit existing production and application workflows in the construction industry.
A key barrier to deploying such materials is the lack of mechanistic understanding of how new binders form, evolve, and interact with CO2 and water across length scales. The project therefore adopts an atomic-to-material design pathway. At the smallest scale, it will uncover how key mineral building blocks form, dissolve, and reorganise, and how CO2 can be incorporated into stable solid phases. These insights will guide the rational design of binder compositions and processing routes. At the material scale, the project will translate atomic-level understanding into formulations with targeted mechanical strength, durability, and carbonation capacity. This multi-scale pathway is essential to move beyond trial-and-error development and toward predictable, tunable low-carbon concrete systems.
The expected impacts are significant in scale and relevance. Scientifically, the project will provide a foundational understanding of carbon-incorporating cementitious materials, enabling a new paradigm for sustainable binder design. Technologically, it will deliver design principles and candidate formulations for clinker-free concrete with negative net CO2 footprints, compatible with existing construction practices. Societally and economically, the project supports Europe’s transition toward climate-neutral infrastructure by opening pathways to reduce emissions from one of the hardest-to-abate industrial sectors, while strengthening innovation capacity in green construction materials. By contributing knowledge and tools for carbon-negative concrete, the project aligns with European strategies on climate action, circular economy, and sustainable urban development, and lays the groundwork for future industrial uptake and policy-relevant innovation in low-carbon construction.
This project addresses this challenge by developing a new class of zero-clinker, negative-CO2 concrete. The core idea is to replace conventional clinker-based binders with alternative mineral systems that can be synthesised at lower temperatures and designed to actively capture and mineralise CO2 during curing and service life. By integrating carbon into the material itself, concrete can shift from being a major carbon source to becoming part of the climate solution. This approach directly responds to the need for scalable, durable, and economically viable low-carbon construction materials that fit existing production and application workflows in the construction industry.
A key barrier to deploying such materials is the lack of mechanistic understanding of how new binders form, evolve, and interact with CO2 and water across length scales. The project therefore adopts an atomic-to-material design pathway. At the smallest scale, it will uncover how key mineral building blocks form, dissolve, and reorganise, and how CO2 can be incorporated into stable solid phases. These insights will guide the rational design of binder compositions and processing routes. At the material scale, the project will translate atomic-level understanding into formulations with targeted mechanical strength, durability, and carbonation capacity. This multi-scale pathway is essential to move beyond trial-and-error development and toward predictable, tunable low-carbon concrete systems.
The expected impacts are significant in scale and relevance. Scientifically, the project will provide a foundational understanding of carbon-incorporating cementitious materials, enabling a new paradigm for sustainable binder design. Technologically, it will deliver design principles and candidate formulations for clinker-free concrete with negative net CO2 footprints, compatible with existing construction practices. Societally and economically, the project supports Europe’s transition toward climate-neutral infrastructure by opening pathways to reduce emissions from one of the hardest-to-abate industrial sectors, while strengthening innovation capacity in green construction materials. By contributing knowledge and tools for carbon-negative concrete, the project aligns with European strategies on climate action, circular economy, and sustainable urban development, and lays the groundwork for future industrial uptake and policy-relevant innovation in low-carbon construction.
Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent
The project carried out coordinated experimental and atomistic-modelling activities to establish a mechanistic foundation for designing low-carbon, clinker-free binders with CO2 incorporation potential.
At the experimental level, preliminary feasibility studies were conducted on alternative mineral feedstocks relevant to low-carbon cement systems. Electrochemical activation of industrial gypsum was explored as a proof-of-concept route to convert calcium sulfate into reactive calcium-rich precursors under mild conditions, aiming to bypass energy-intensive clinker formation. In parallel, waste concrete collected from coastal environments was characterised and reprocessed to assess its suitability as a secondary calcium–silicate source. These studies provided first evidence that coastal waste concrete can be selectively activated and repurposed as a low-carbon binder precursor, while electrochemical treatment offers a controllable pathway to tune reactivity and phase composition. The outcomes define practical processing windows and constraints for future scale-up studies of clinker-free binders using industrial residues and marine-exposed concrete waste.
At the atomic scale, first-principles molecular dynamics and enhanced-sampling simulations were performed to resolve the dissolution of calcium from cementitious solid surfaces in aqueous environments. The simulations explicitly captured the stepwise detachment of surface calcium ions from tricalcium silicate in the presence of water and common interfacial ions. Free-energy landscapes and minimum free-energy reaction pathways were constructed, revealing that calcium detachment proceeds through ligand-exchange reactions in which surface Ca–O bonds are progressively replaced by Ca–O(water) coordination. The computed free-energy barriers (on the order of tens of kJ mol⁻¹) identify the rate-limiting step for early-stage dissolution and quantify how interfacial chemistry modulates reactivity. These results provide a molecular mechanism for ion release at cement–water interfaces and explain how solution chemistry can either hinder or facilitate early hydration reactions. The atomistic insights are directly relevant for rationally designing low-clinker binders with controlled dissolution and carbonation behaviour, as required for carbon-negative cement systems.
By integrating these two research lines, the project established a bottom-up design logic linking interfacial reaction mechanisms to material-level processing strategies. The experimental screening of electrochemically activated gypsum and coastal waste concrete demonstrated viable low-carbon precursor routes, while the atomistic simulations delivered quantitative mechanistic parameters to guide composition tuning and curing strategies. Together, these outcomes form a scientific and technical basis for the subsequent development of zero-clinker, CO2-incorporating concrete materials.
At the experimental level, preliminary feasibility studies were conducted on alternative mineral feedstocks relevant to low-carbon cement systems. Electrochemical activation of industrial gypsum was explored as a proof-of-concept route to convert calcium sulfate into reactive calcium-rich precursors under mild conditions, aiming to bypass energy-intensive clinker formation. In parallel, waste concrete collected from coastal environments was characterised and reprocessed to assess its suitability as a secondary calcium–silicate source. These studies provided first evidence that coastal waste concrete can be selectively activated and repurposed as a low-carbon binder precursor, while electrochemical treatment offers a controllable pathway to tune reactivity and phase composition. The outcomes define practical processing windows and constraints for future scale-up studies of clinker-free binders using industrial residues and marine-exposed concrete waste.
At the atomic scale, first-principles molecular dynamics and enhanced-sampling simulations were performed to resolve the dissolution of calcium from cementitious solid surfaces in aqueous environments. The simulations explicitly captured the stepwise detachment of surface calcium ions from tricalcium silicate in the presence of water and common interfacial ions. Free-energy landscapes and minimum free-energy reaction pathways were constructed, revealing that calcium detachment proceeds through ligand-exchange reactions in which surface Ca–O bonds are progressively replaced by Ca–O(water) coordination. The computed free-energy barriers (on the order of tens of kJ mol⁻¹) identify the rate-limiting step for early-stage dissolution and quantify how interfacial chemistry modulates reactivity. These results provide a molecular mechanism for ion release at cement–water interfaces and explain how solution chemistry can either hinder or facilitate early hydration reactions. The atomistic insights are directly relevant for rationally designing low-clinker binders with controlled dissolution and carbonation behaviour, as required for carbon-negative cement systems.
By integrating these two research lines, the project established a bottom-up design logic linking interfacial reaction mechanisms to material-level processing strategies. The experimental screening of electrochemically activated gypsum and coastal waste concrete demonstrated viable low-carbon precursor routes, while the atomistic simulations delivered quantitative mechanistic parameters to guide composition tuning and curing strategies. Together, these outcomes form a scientific and technical basis for the subsequent development of zero-clinker, CO2-incorporating concrete materials.
Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)
The project delivered two complementary sets of results that together advance the scientific basis and technical feasibility of clinker-free, carbon-negative concrete.
First, at the material and process level, the project demonstrated preliminary routes to generate reactive calcium–silicate precursors without conventional clinker production. Electrochemical activation of gypsum showed that calcium-rich phases can be produced under mild conditions, opening a pathway to low-temperature binder synthesis that avoids limestone calcination. In parallel, waste concrete from coastal environments was characterised and reprocessed, confirming its potential as a secondary calcium–silicate source for new binder formulations. These results indicate that industrial by-products and end-of-life concrete can be reintegrated into a low-carbon cement cycle, reducing raw-material demand and diverting construction waste from landfill. Together, these outcomes provide early technical evidence for circular, low-emission binder supply chains.
Second, at the atomic and molecular levels, first-principles simulations resolved the mechanism and energetics of calcium dissolution at cement–water interfaces. The results quantified free-energy barriers and identified the rate-limiting step governing early-stage ion release from mineral surfaces. This mechanistic understanding enables predictive control of dissolution and subsequent carbonation or hydration reactions. The atomistic insights provide design rules for tuning binder composition and curing environments to promote stable CO2 incorporation while preserving mechanical performance. These results establish a transferable framework for rational design of next-generation cementitious binders beyond empirical trial-and-error approaches.
Potential impacts. Scientifically, the project advances fundamental knowledge of interfacial reactions in cementitious systems and provides quantitative parameters for multiscale modelling of low-carbon binders. Technologically, it outlines viable pathways toward zero-clinker binder production and identifies atomic-scale levers to control reactivity and carbonation efficiency. Societally and environmentally, successful translation of these results could contribute to substantial reductions in CO2 emissions from the construction sector and support circular use of mineral resources and construction waste. In the longer term, these advances can inform the development of climate-positive concrete solutions aligned with European climate-neutrality and circular-economy goals.
Key needs for further uptake and success.
To enable broader adoption and real-world impact, several steps are required: Further research and validation: Scale up laboratory findings to pilot-scale synthesis and curing trials, including long-term durability and mechanical performance under realistic service conditions. Demonstration and integration: Demonstrate compatibility with existing concrete production and curing workflows, including CO2 curing or mineralisation routes at pilot scale. Access to markets and finance: Support early-stage demonstration through targeted funding and partnerships with materials producers and construction stakeholders. Commercialisation and IPR: Protect key process innovations and material formulations to facilitate industrial uptake and technology transfer. Regulatory and standardisation frameworks: Develop testing protocols and performance standards for clinker-free and carbon-negative binders to enable certification and market entry. Internationalisation: Engage with global construction markets and standards bodies to ensure interoperability and accelerate deployment beyond regional contexts.
Overall, the project provides a scientifically grounded starting point for transforming cement from a major carbon source into a platform for carbon storage, while highlighting the research, demonstration, and policy support needed to translate these advances into deployable low-carbon construction technologies.
First, at the material and process level, the project demonstrated preliminary routes to generate reactive calcium–silicate precursors without conventional clinker production. Electrochemical activation of gypsum showed that calcium-rich phases can be produced under mild conditions, opening a pathway to low-temperature binder synthesis that avoids limestone calcination. In parallel, waste concrete from coastal environments was characterised and reprocessed, confirming its potential as a secondary calcium–silicate source for new binder formulations. These results indicate that industrial by-products and end-of-life concrete can be reintegrated into a low-carbon cement cycle, reducing raw-material demand and diverting construction waste from landfill. Together, these outcomes provide early technical evidence for circular, low-emission binder supply chains.
Second, at the atomic and molecular levels, first-principles simulations resolved the mechanism and energetics of calcium dissolution at cement–water interfaces. The results quantified free-energy barriers and identified the rate-limiting step governing early-stage ion release from mineral surfaces. This mechanistic understanding enables predictive control of dissolution and subsequent carbonation or hydration reactions. The atomistic insights provide design rules for tuning binder composition and curing environments to promote stable CO2 incorporation while preserving mechanical performance. These results establish a transferable framework for rational design of next-generation cementitious binders beyond empirical trial-and-error approaches.
Potential impacts. Scientifically, the project advances fundamental knowledge of interfacial reactions in cementitious systems and provides quantitative parameters for multiscale modelling of low-carbon binders. Technologically, it outlines viable pathways toward zero-clinker binder production and identifies atomic-scale levers to control reactivity and carbonation efficiency. Societally and environmentally, successful translation of these results could contribute to substantial reductions in CO2 emissions from the construction sector and support circular use of mineral resources and construction waste. In the longer term, these advances can inform the development of climate-positive concrete solutions aligned with European climate-neutrality and circular-economy goals.
Key needs for further uptake and success.
To enable broader adoption and real-world impact, several steps are required: Further research and validation: Scale up laboratory findings to pilot-scale synthesis and curing trials, including long-term durability and mechanical performance under realistic service conditions. Demonstration and integration: Demonstrate compatibility with existing concrete production and curing workflows, including CO2 curing or mineralisation routes at pilot scale. Access to markets and finance: Support early-stage demonstration through targeted funding and partnerships with materials producers and construction stakeholders. Commercialisation and IPR: Protect key process innovations and material formulations to facilitate industrial uptake and technology transfer. Regulatory and standardisation frameworks: Develop testing protocols and performance standards for clinker-free and carbon-negative binders to enable certification and market entry. Internationalisation: Engage with global construction markets and standards bodies to ensure interoperability and accelerate deployment beyond regional contexts.
Overall, the project provides a scientifically grounded starting point for transforming cement from a major carbon source into a platform for carbon storage, while highlighting the research, demonstration, and policy support needed to translate these advances into deployable low-carbon construction technologies.