Project

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Role of water redistribution in creep of concrete

Applicant Wyrzykowski Mateusz
Number 161414
Funding scheme Ambizione
Research institution Abteilung Beton / Bauchemie EMPA
Institution of higher education Swiss Federal Laboratories for Materials Science and Technology - EMPA
Main discipline Material Sciences
Start/End 01.10.2015 - 30.09.2018
Approved amount 503'459.00
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All Disciplines (2)

Discipline
Material Sciences
Civil Engineering

Keywords (9)

Cement; Concrete; Cracking; Creep; Shrinkage; Durability; Sustainability; Nuclear Magnetic Resonance; Modeling

Lay Summary (German)

Lead
Beton ist das wichtigste Baumaterial und das am meisten hergestellte Material weltweit. Gleichzeitig sind Rissbildung und reduzierte Dauerhaftigkeit mehr und mehr ein akutes Problem, das die Anwendung von umweltfreundlichen und nachhaltigen Betonen verzögert. Eine zuverlässige Vorhersage der Rissbildung des Betons ist praktisch nicht möglich, vor allem wegen des Mangels an Grundlagenverständnis der kurzfristigen viskoelastischen Phänomene von Kriechen und Relaxation von Spannungen. Dank der Erforschung der Rolle der Umverteilung von Wasser bei mechanischer Belastung soll ein Fortschritt in dem grundlegenden Verständnis der Kriechmechanismen erreicht werden.
Lay summary

Inhalt und Ziel des Forschungsprojekts

Mein übergeordnetes Ziel ist die quantitative Beschreibung der Wasserbewegungen in der Mikrostruktur von Beton während einer Belastung. Um dieses Ziel zu erreichen, werde ich die Spitzentechnologie Wasserstoff-Kernspinresonanz benutzen. Gleichzeitig werde ich die korrespondierenden Kriechdeformationen und Änderungen der relativen Feuchtigkeit in den Poren quantifizieren. Um eine praktische Beschreibung des Kriechens von Beton zu ermöglichen, werde ich hochaktuelle poromechanische Modellierungsmethoden verwenden.

Wissenschaftlicher und gesellschaftlicher Kontext des Forschungsprojekts

Basierend auf experimentellen Untersuchungen und theoretischen Überlegungen wird dieses Projekt helfen, eine Lücke im Verständnis von Kriechen und Relaxation von Beton zu füllen und ein erweitertes Verständnis des Problems bieten.

Eine bessere Beschreibung von Kriechen und Relaxation wird eine genauere und robustere Vorhersage von Verformungen und Rissbildungen des Betons ermöglichen. Dies wird einen dauerhaften und sicheren, wie auch ökonomisch effizienten Einsatz von Beton gestatten. Das ist speziell wichtig, da allein die in der Schweiz hergestellte Betonmenge 38 Mio Tonnen pro Jahr mit einem Umsatz von über 2.3 Mio CHF erreicht.

Direct link to Lay Summary Last update: 21.08.2015

Responsible applicant and co-applicants

Employees

Publications

Publication
Water Redistribution–Microdiffusion in Cement Paste under Mechanical Loading Evidenced by 1 H NMR
Wyrzykowski Mateusz, Gajewicz-Jaromin Agata M., McDonald Peter J., Dunstan David J., Scrivener Karen L., Lura Pietro (2019), Water Redistribution–Microdiffusion in Cement Paste under Mechanical Loading Evidenced by 1 H NMR, in The Journal of Physical Chemistry C, 123(26), 16153-16163.
Basic creep of cement paste at early age - the role of cement hydration
Wyrzykowski Mateusz, Scrivener Karen, Lura Pietro (2019), Basic creep of cement paste at early age - the role of cement hydration, in Cement and Concrete Research, 116, 191-201.
A novel method to predict internal relative humidity in cementitious materials by H-1 NMR
Hu Zhangli, Wyrzykowski Mateusz, Scrivener Karen, Lura Pietro (2018), A novel method to predict internal relative humidity in cementitious materials by H-1 NMR, in CEMENT AND CONCRETE RESEARCH, 104, 80-93.
Water Redistribution within the Microstructure of Cementitious Materials due to Temperature Changes Studied with 1H NMR
Wyrzykowski Mateusz, McDonald Peter J, Scrivener Karen, Lura Pietro (2017), Water Redistribution within the Microstructure of Cementitious Materials due to Temperature Changes Studied with 1H NMR, in The Journal of Physical Chemistry C, 1.
Elastic and Visco-Elastic Behavior of Cementitious Materials at Early Ages
Hu Zhangli, Hilaire Adrien, Wyrzykowski Mateusz, Scrivener Karen, Lura Pietro (2017), Elastic and Visco-Elastic Behavior of Cementitious Materials at Early Ages, in Poromechanics 2017 - Proceedings of the 6th Biot Conference on Poromechanics, Paris, FranceASCE Library, Reston, VA.
Prediction of Drying Shrinkage of Cement-Based Mortars with Poroelastic Approaches—A Critical Review
Wyrzykowski Mateusz, Di Bella Carmelo, Lura Pietro (2017), Prediction of Drying Shrinkage of Cement-Based Mortars with Poroelastic Approaches—A Critical Review, in Poromechanics 2017 - Proceedings of the 6th Biot Conference on Poromechanics, Paris, FranceASCE Library, Reston, VA.

Collaboration

Group / person Country
Types of collaboration
School of Physics and Astronomy, Queen Mary, University of London Great Britain and Northern Ireland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Department of Physics/University of Surrey Great Britain and Northern Ireland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Conference in honour of the centennial of LMC and Karen Scrivener’s 60th birthday Talk given at a conference WATER REDISTRIBUTION IN MICROSTRUCTURE OF CEMENT PASTE AT THERMAL LOADING 19.08.2018 EPFL, Switzerland Wyrzykowski Mateusz;
Gordon Research Conference - Advanced Materials for Sustainable Infrastructure Development Talk given at a conference Basic Creep of Concrete at Early-Ages: Fundamental Mechanisms Assessed in Equivalent Systems with Arrested Hydration 05.08.2018 The Hong Kong University of Science and Technology, Hong Kong, Hongkong Wyrzykowski Mateusz;
6th Biot Conference on Poromechanics Talk given at a conference Prediction of Drying Shrinkage of Cement-Based Mortars with Poroelastic Approaches - A Critical Review 09.07.2017 Paris, France Wyrzykowski Mateusz;
9th International Conference on Porous Media Poster Redistribution of water in nanometer-sized pores in hardened cement paste due to temperature change. A Nuclear Magnetic Resonance (NMR) study 08.05.2017 Rotterdam, Netherlands Wyrzykowski Mateusz;
9th International Conference on Porous Media Talk given at a conference Shrinkage of concrete as an effect of hygro-mechanical coupling in unsaturated porous body – experimental and theoretical study of different poroelastic approaches 08.05.2017 Rotterdam, Netherlands Wyrzykowski Mateusz;


Abstract

Concrete is the most important building material worldwide. In Switzerland alone, 38 Mio tons were produced in 2013, with a revenue of 2’360 Mio CHF. About 5-7% of anthropogenic CO2 emission comes only from cement industry. More sustainable concrete is necessary for addressing the environmental and energy supply challenges of today and tomorrow’s society. This can be achieved by using high performance concretes (HPC) and/or cements with replacement of cement clinker with supplementary cementitious materials (SCM). However, concretes with high contents of SCM, in particular HPC, have higher risk of cracking in the first days to weeks after placing. The current poor understanding of the fundamental mechanisms underlying early-age cracking is in fact delaying the acceptance of modern concretes. Cracking is caused by restrained deformations occurring at loading, drying and temperature changes. While the stresses build up due to restrained deformations, they are relaxed by viscoelastic deformations of the concrete (manifesting as creep and stress relaxation). Short-term stress relaxation at early ages can reduce the theoretical elastic restraint stresses by 50-80% and avoid cracking. However, despite the large body of studies on concrete cracking, little is known about the mechanisms underlying creep. This project focuses on the role of short-term creep accompanying mechanical loading, shrinkage and thermal deformations. An advancement in fundamental understanding of creep mechanisms will be achieved by clarifying the role of water redistribution during mechanical loading, drying and temperature changes. Until recently, no experimental evidence of changes in the moisture state of cementitious materials accompanying mechanical loading and creep had been produced. However, a recent study by the applicant shows the first direct evidence of such phenomenon. The missing part regards however the explicit observation of water redistribution. In the last couple of years, new possibilities for in-situ non-destructive studying of moisture distribution in cementitious materials were opened with Nuclear Magnetic Resonance (NMR) relaxometry, in particular in a collaboration between the University of Surrey and EPF Lausanne (EPFL). The breakthrough approach of the present proposal consists in studying water redistribution upon loading with in-situ NMR relaxometry combined with the measurements of RH and deformations due to creep. It is expected that this approach will cast new light on the mechanisms causing creep/relaxation and on their influence on concrete cracking. This is only possible by taking advantage of the state-of-the-art experimental facilities for studying concrete deformations available at Empa (main host), combined with the NMR at EPFL (co-host) and University of Surrey (visits). The applicant will face a major experimental challenge that has not been addressed so far for studying concrete creep; in the project special loading cells will be constructed to load the samples with pressure, drying and temperature changes while performing NMR measurements, to enable in-situ following of water redistribution responsible for short term creep. In parallel, cutting-edge modelling approaches will be developed for description of short-term creep in collaboration with Vienna University of Technology (visits). This creep model will be then integrated in a poromechanical framework for predictions of concrete creep and relaxation. The high impact of the proposed project will be achieved thanks to combining the efforts of the four academic institutions involved, and the dissemination and outreach activities within the networks: RILEM, Nanocem and COST TU1404. The applicant will be appointed at Empa and will spend about 50% of his working time (on a regular basis) at EPFL, where he will run the experimental work with NMR. This dynamic mobility program will enable intense research synergies which are essential for achieving a breakthrough in the prediction of concrete creep. It will also constitute an important step in the career of the applicant, enhancing his professional development in technical and scientific skills, as well as extending his professional network and recognition. These assets will highly increase the scientific competitiveness of the applicant in the research field worldwide.
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