Sustainable Construction | DUBiT Center of Expertise

Eco²-crete mortars: sustainable and ecological concrete repair

With Eco²-crete mortars, we investigate how concrete repair can become more sustainable without compromising technical performance. This is increasingly important as many concrete structures are reaching the end of their design service life, while conventional repair mortars often contain large amounts of Portland clinker, have a considerable environmental impact, and can be prone to shrinkage cracking. Through market analysis, stakeholder consultations, and experimental testing, we explore how alternative binders and superabsorbent polymers can improve the performance and sustainability of repair mortars. Discover how this research contributes to extending the service life of concrete structures and supporting the transition towards a more circular and sustainable construction sector.

Cement or mortar, Cement powder with a trowel put on the brick at construction work.
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PWO SG TECH
Summary

  • What?

    Eco²-crete mortars develops innovative knowledge and practical guidance for sustainable concrete repair through the use of alternative binders and superabsorbent polymers, combining high performance with a reduced environmental impact.

  • How?

    The project combines literature and market research, stakeholder consultations, and laboratory testing to evaluate key performance aspects such as workability, setting behaviour, shrinkage, strength, adhesion, and durability.

  • Who is this for?

    The project is relevant to manufacturers, designers, engineering consultants, concrete repair contractors, asset owners, infrastructure managers, industry associations, researchers, educators, and students working in the fields of construction and concrete technology.

Problem Statement

Many reinforced concrete structures built during the 1960s and 1970s are now reaching the end of their intended service life. As a result, the demand for concrete rehabilitation and repair mortars is steadily increasing. Traditional cement-based repair mortars typically contain high amounts of Portland clinker, which contributes significantly to their environmental footprint.

In addition, their low water-to-cement ratio can lead to autogenous shrinkage and cracking. These cracks may allow harmful substances to penetrate the repaired structure, compromising durability and preventing the intended extension of the service life from being fully achieved. Consequently, there is a growing need for more sustainable and durable repair mortars that combine reduced environmental impact with improved long-term performance.

Objective

Eco²-crete aims to lay the foundations for repair mortars that are both technically durable and environmentally sustainable. The project investigates to what extent Supplementary Cementitious Materials (SCMs), such as slag, geopolymers, and incineration bottom ashes, can replace Portland clinker in repair mortar formulations. In addition, the research explores whether superabsorbent polymers (SAPs) can help reduce shrinkage and crack formation.

The project seeks to identify which mortar compositions are best suited to specific performance requirements, substrate conditions, and application methods. By combining improved durability with a lower environmental impact, Eco²-crete aims to support the development of next-generation concrete repair solutions that contribute to a more sustainable construction sector.

Research questions

  1. How can sustainable repair mortars be developed and applied to optimise both environmental and technical performance, taking into account material selection, environmental impact, and cost-effectiveness?
  2. Which conventional and alternative commercial repair mortars and superabsorbent polymer (SAP) materials are currently available, what are their compositions and properties, and what knowledge is required for their safe and effective application?
  3. How do alternative binders and superabsorbent polymers influence workability, shrinkage, mechanical properties, adhesion, and suitability for different application techniques and substrate conditions?

Research approach

  1. Market exploration and knowledge mapping
    The project begins with a comprehensive review of the state of the art through literature research, roundtable discussions, and expert interviews. Stakeholders include academic institutions, engineering consultancies, manufacturers and suppliers, concrete repair contractors, industry organisations, and project owners.
  2. Experimental research
    Starting from a reference repair mortar, Portland cement clinker will be progressively replaced by alternative binders, while superabsorbent polymers (SAPs) will be incorporated into selected formulations. The resulting mixtures will be tested for a range of key performance indicators, including workability, setting time, shrinkage, mechanical strength, adhesion, and durability.
  3. Translation into practical outputs
    The findings will be translated into practical guidelines and disseminated through targeted knowledge-sharing activities. The project will also prepare the groundwork for potential follow-up research projects and applications for external funding

Expected Outputs

  1. Materials and Knowledge Database
    A database containing information on repair mortar compositions, material properties, environmental impacts, and the results of experimental testing.
  2. Practical Guidelines
    Evidence-based guidelines for the use of superabsorbent polymers (SAPs) and clinker-replacing binders, tailored to specific performance requirements and application contexts.
  3. Decision-Support Framework
    A potential methodology to support the selection of sustainable, performance-based repair mortars. In future research, this framework may be complemented by life cycle assessment (LCA) and life cycle cost analysis (LCCA).
  4. Knowledge Dissemination
    Scientific publications, conference presentations, study days, workshops, and practice-oriented training sessions for professionals in the construction sector.
  5. Integration into Education
    The knowledge generated by the project will be incorporated into the Construction programme through lectures, bachelor’s theses, laboratory testing, and project-based learning activities.
  6. Demonstration Setup
    A potential demonstration installation showcasing the different stages of concrete repair, various repair mortar types, and common failure mechanisms, making the concepts tangible for students and professionals alike.

Impact and Relevance

The project supports the transition towards a more sustainable and circular construction sector. Reducing the clinker content of repair mortars can significantly lower their carbon footprint, while improved control of shrinkage and cracking can extend the service life of repaired concrete structures. This contributes to reduced material consumption, fewer replacement interventions, lower costs, and less disruption to society.

At the same time, the project strengthens the knowledge base of both students and industry professionals, providing the construction sector with practical, scientifically grounded insights for safer, more durable, and more sustainable concrete repair practices.

Would you like to learn more about Eco²-crete mortars, or are you interested in collaborating on sustainable concrete repair?

Topics: #Eco2Crete #ConcreteRepair #SustainableConstruction #CircularConstruction #ConcreteTechnology #MaterialInnovation #CO2Reduction

Meet the Researchers