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Publications (10 of 144) Show all publications
Nilsson, M., Nilimaa, J., Emborg, M., Hösthagen, A. & Westerholm, M. (2024). Analysmetodik och materialmodeller vid inmätning av ung betongs egenskaper för beräkning av temperatur, hållfasthet och spänningar under härdningsförlopp. Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Analysmetodik och materialmodeller vid inmätning av ung betongs egenskaper för beräkning av temperatur, hållfasthet och spänningar under härdningsförlopp
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2024 (Swedish)Report (Other academic)
Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2024. p. 102
Series
Technical report / Luleå University of Technology, ISSN 1402-1536
National Category
Infrastructure Engineering
Research subject
Structural Engineering; Building Materials
Identifiers
urn:nbn:se:ltu:diva-108191 (URN)978-91-8048-611-8 (ISBN)
Projects
Trafikverkets och Anläggning AMAs metoder för undvikande av tidig sprickbildning i betong – nyutveckling med hänsyn till miljökriterier
Funder
Swedish Transport Administration, FOI-BBTSvenska Byggbranschens Utvecklingsfond (SBUF)
Note

Funder: Heidelberg Materials, Cement och Betong

Available from: 2024-06-28 Created: 2024-06-28 Last updated: 2024-07-02Bibliographically approved
Nilsson, M., Nilimaa, J., Emborg, M., Hösthagen, A. & Westerholm, M. (2024). Materialdata för beräkning av temperatur, hållfasthet och spänningar – betong med AnlFA-cement, flygaska och slagg. Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Materialdata för beräkning av temperatur, hållfasthet och spänningar – betong med AnlFA-cement, flygaska och slagg
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2024 (Swedish)Report (Other academic)
Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2024. p. 38
Series
Technical report / Luleå University of Technology, ISSN 1402-1536
National Category
Infrastructure Engineering Other Materials Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-106153 (URN)978-91-8048-597-5 (ISBN)
Projects
Trafikverkets och Anläggning AMAs metoder för undvikande av tidig sprickbildning i betong – nyutveckling med hänsyn till miljökriterier
Available from: 2024-06-10 Created: 2024-06-10 Last updated: 2024-06-10Bibliographically approved
Nilsson, M., Nilimaa, J., Emborg, M., Hösthagen, A. & Westerholm, M. (2024). Spänningsberäkningar, metodik och kriterier. Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Spänningsberäkningar, metodik och kriterier
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2024 (Swedish)Report (Other academic)
Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2024. p. 30
Series
Technical report / Luleå University of Technology, ISSN 1402-1536
National Category
Infrastructure Engineering
Research subject
Structural Engineering; Building Materials
Identifiers
urn:nbn:se:ltu:diva-108190 (URN)978-91-8048-610-1 (ISBN)
Projects
Trafikverkets och Anläggning AMAs metoder för undvikande av tidig sprickbildning i betong – nyutveckling med hänsyn till miljökriterier
Funder
Swedish Transport Administration, FOI-BBTSvenska Byggbranschens Utvecklingsfond (SBUF)
Note

Funder: Heidelberg Materials, Cement och Betong

Available from: 2024-06-28 Created: 2024-06-28 Last updated: 2024-07-02Bibliographically approved
Gamil, Y., Nilimaa, J., Cwirzen, A. & Emborg, M. (2023). Experimental based assessment of formwork pressure theoretical design models for self-compacting concrete. Journal of Building Engineering, 68, Article ID 106085.
Open this publication in new window or tab >>Experimental based assessment of formwork pressure theoretical design models for self-compacting concrete
2023 (English)In: Journal of Building Engineering, E-ISSN 2352-7102, Vol. 68, article id 106085Article in journal (Refereed) Published
Abstract [en]

Self-Compacting Concrete (SCC) offers favourable properties which help accelerate the casting time, especially in congested reinforced structures but when casting with SCC uncertainty remains a challenge on the behaviour of its formwork pressure. Researchers have introduced several design models to predict pressure and its behaviour. This research aims to assess the design models that have been reported in the literature. The assessment was carried out through a series of rigorous laboratory tests and the results from the tests served as input for the mathematical model evaluation. Twelve concrete columns with 2 m height were cast in the laboratory to study the effect of varying the input parameters in the existing design models. The formwork pressure was documented by a pressure monitoring system, with the capacity to produce instant results for real-time remote monitoring of the pressure development during and after concrete casting. The formwork pressures were calculated according to the current design models and were compared with pressure data acquitted from the laboratory tests. The results showed that the pressure predicted by the design models was typically greater than the pressure observed during the laboratory tests. The DIN18218 design model showed a relatively close approximation of the pressure distribution over the formwork height and casting time. The limitation of the models is observed when the casting rate varies, and models are sensitive to the input parameters. Thus, additional development of the current design models is needed to enable reliable estimations of the pressure, for example, in the case of low and high casting rates. The laboratory tests also showed that high casting rates and high slump flows generate higher pressures whereas higher thixotropy results in faster pressure reduction during construction.

Place, publisher, year, edition, pages
Elsevier Ltd, 2023
Keywords
Cast in place, Casting rate, Concrete construction, Formwork pressure, Modelling, Self compacting concrete, Slump flow, Thixotropy
National Category
Other Materials Engineering Infrastructure Engineering
Research subject
Building Materials
Identifiers
urn:nbn:se:ltu:diva-95818 (URN)10.1016/j.jobe.2023.106085 (DOI)001012837700001 ()2-s2.0-85149059320 (Scopus ID)
Funder
Svenska Byggbranschens Utvecklingsfond (SBUF)
Note

Validerad;2023;Nivå 2;2023-03-08 (joosat);

Funder: NCC AB

Licens fulltext: CC BY License

Available from: 2023-03-08 Created: 2023-03-08 Last updated: 2024-03-07Bibliographically approved
Gamil, Y., Cwirzen, A., Nilimaa, J. & Emborg, M. (2023). The Impact of Different Parameters on the Formwork Pressure Exerted by Self-Compacting Concrete. Materials, 16(2), Article ID 759.
Open this publication in new window or tab >>The Impact of Different Parameters on the Formwork Pressure Exerted by Self-Compacting Concrete
2023 (English)In: Materials, E-ISSN 1996-1944, Vol. 16, no 2, article id 759Article in journal (Refereed) Published
Abstract [en]

Despite the advantageous benefits offered by self-compacting concrete, its uses are still limited due to the high pressure exerted on the formwork. Different parameters, such as those related to concrete mix design, the properties of newly poured concrete, and placement method, have an impact on form pressure. The question remains unanswered on the degree of the impact for each parameter. Therefore, this study aims to study the level of impact of these parameters, including slump flow, T500 time, fresh concrete density, air content, static yield stress, concrete setting time, and concrete temperature. To mimic the casting scenario, 2 m columns were cast at various casting rates and a laboratory setup was developed. A pressure system that can wirelessly and continuously record pressure was used to monitor the pressure. Each parameter’s impact on the level of pressure was examined separately. Casting rate and slump flow were shown to have a greater influence on pressure. The results also demonstrated that, while higher thixotropy causes form pressure to rapidly decrease, a high casting rate and high slump flow lead to high pressure. This study suggests that more thorough analysis should be conducted of additional factors that may have an impact, such as the placement method, which was not included in this publication.

Place, publisher, year, edition, pages
MDPI, 2023
Keywords
formwork, parameters, pressure, self-compacting concrete
National Category
Other Materials Engineering
Research subject
Building Materials
Identifiers
urn:nbn:se:ltu:diva-95541 (URN)10.3390/ma16020759 (DOI)000927643400001 ()2-s2.0-85146533983 (Scopus ID)
Funder
Svenska Byggbranschens Utvecklingsfond (SBUF)
Note

Validerad;2023;Nivå 2;2023-02-08 (joosat);

Licens fulltext: CC BY License

Available from: 2023-02-08 Created: 2023-02-08 Last updated: 2024-07-04Bibliographically approved
Sayahi, F., Emborg, M., Hedlund, H. & Ghasemi, Y. (2022). Experimental validation of a novel method for estimating the severity of plastic shrinkage cracking in concrete. Construction and Building Materials, 339, Article ID 127794.
Open this publication in new window or tab >>Experimental validation of a novel method for estimating the severity of plastic shrinkage cracking in concrete
2022 (English)In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 339, article id 127794Article in journal (Refereed) Published
Abstract [en]

Plastic shrinkage cracking in cementitious materials is caused mainly by rapid and excessive moisture loss during mixture’s early ages, before sufficient tensile strength is gained. A novel model has been previously developed by the authors to estimate the severity of plastic shrinkage cracking in concrete. This paper presents findings of a series of full-scale experiments carried out to validate the accuracy of the proposed model. The experiments included investigating the impact of cement type, water-cement ratio (w/c), and admixtures (i.e., accelerator, retarder, and superplasticizer). The tests were performed in three rounds under similar ambient conditions using 3 slabs (3 m × 2 m) and 3 ring test moulds at each round. The results confirm the accuracy of the model in anticipating/comparing the cracking severity of the tested concretes.

Place, publisher, year, edition, pages
Elsevier, 2022
Keywords
Shrinkage, Cracking, Modelling, Cement type, W/c ratio, Admixtures
National Category
Applied Mechanics Other Civil Engineering
Research subject
Building Materials
Identifiers
urn:nbn:se:ltu:diva-90823 (URN)10.1016/j.conbuildmat.2022.127794 (DOI)000804098100002 ()2-s2.0-85130409267 (Scopus ID)
Funder
Svenska Byggbranschens Utvecklingsfond (SBUF)
Note

Validerad;2022;Nivå 2;2022-05-31 (joosat);

Available from: 2022-05-31 Created: 2022-05-31 Last updated: 2022-06-20Bibliographically approved
Sayahi, F., Emborg, M., Hedlund, H. & Cwirzen, A. (2021). Effect of Steel Fibres Extracted from Recycled Tyres on Plastic Shrinkage Cracking in Self-Compacting Concrete. Magazine of Concrete Research, 73(24), 1270-1282, Article ID 2000116.
Open this publication in new window or tab >>Effect of Steel Fibres Extracted from Recycled Tyres on Plastic Shrinkage Cracking in Self-Compacting Concrete
2021 (English)In: Magazine of Concrete Research, ISSN 0024-9831, E-ISSN 1751-763X, Vol. 73, no 24, p. 1270-1282, article id 2000116Article in journal (Refereed) Published
Abstract [en]

This paper investigates and compares the effect of steel fibres obtained through recycling waste tyres (known as RTSF), and a commercially available hooked steel fibre (HSF), on plastic shrinkage cracking in self-compacting concrete. The volumetric deformations of the specimens, bleeding, and the mass loss have been quantified. Mixtures containing 2.5, 5, 7.5 and 10 kg/m3 of RTSF, and 5 and 7.5 kg/m3 of HSF have been tested. The results show that an almost similar reduction of the crack area can be attained if HSF is replaced by a slightly higher amount of RTSF. However, the former seems to be more effective in restraining plastic shrinkage. Both fibres decreased the volumetric shrinkage and the bleeding capacity of the specimens.

Place, publisher, year, edition, pages
Thomas Telford, 2021
Keywords
cracks & cracking, fibre-reinforced concrete, shrinkage
National Category
Civil Engineering
Research subject
Building Materials
Identifiers
urn:nbn:se:ltu:diva-73171 (URN)10.1680/jmacr.20.00116 (DOI)000720068000004 ()2-s2.0-85103350787 (Scopus ID)
Note

Validerad;2021;Nivå 2;2021-11-29 (johcin)

Available from: 2019-03-12 Created: 2019-03-12 Last updated: 2021-11-29Bibliographically approved
Gamil, Y., Nilimaa, J., Emborg, M. & Cwirzen, A. (2021). Lateral Formwork Pressure for Self-Compacting Concrete—A Review of Prediction Models and Monitoring Technologies. Materials, 14(16), Article ID 4767.
Open this publication in new window or tab >>Lateral Formwork Pressure for Self-Compacting Concrete—A Review of Prediction Models and Monitoring Technologies
2021 (English)In: Materials, E-ISSN 1996-1944, Vol. 14, no 16, article id 4767Article, review/survey (Refereed) Published
Abstract [en]

The maximum amount of lateral formwork pressure exerted by self-compacting concrete is essential to design a technically correct, cost-effective, safe, and robust formwork. A common practice of designing formwork is primarily based on using the hydrostatic pressure. However, several studies have proven that the maximum pressure is lower, thus potentially enabling a reduction in the cost of formwork by, for example, optimizing the casting rate. This article reviews the current knowledge regarding formwork pressure, parameters affecting the maximum pressure, prediction models, monitoring technologies and test setups. The currently used pressure predicting models require further improvement to consider several pressures influencing parameters, including parameters related to fresh and mature material properties, mix design and casting methods. This study found that the maximum pressure is significantly affected by the concretes’ structural build-up at rest, which depends on concrete rheology, temperature, hydration rate and setting time. The review indicates a need for more in-depth studies.

Place, publisher, year, edition, pages
MDPI, 2021
Keywords
self-compacting concrete, form pressure, pressure models, concrete construction
National Category
Other Civil Engineering
Research subject
Building Materials; Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-86829 (URN)10.3390/ma14164767 (DOI)000689561000001 ()34443287 (PubMedID)2-s2.0-85113692977 (Scopus ID)
Funder
Svenska Byggbranschens Utvecklingsfond (SBUF)
Note

Validerad;2021;Nivå 2;2021-09-01 (alebob);

Forskningsfinansiär: NCC

Available from: 2021-08-26 Created: 2021-08-26 Last updated: 2024-07-04Bibliographically approved
Sayahi, F., Emborg, M., Hedlund, H., Cwirzen, A. & Stelmarczyk, M. (2021). The Severity of Plastic Shrinkage Cracking in Concrete: A New Model. Magazine of Concrete Research, 73(6), 315-324
Open this publication in new window or tab >>The Severity of Plastic Shrinkage Cracking in Concrete: A New Model
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2021 (English)In: Magazine of Concrete Research, ISSN 0024-9831, E-ISSN 1751-763X, Vol. 73, no 6, p. 315-324Article in journal (Refereed) Published
Abstract [en]

Plastic shrinkage cracking in concrete is mainly a physical process, in which chemical reactions between cement and water do not play a decisive role. It is commonly believed that rapid and excessive moisture loss, due to evaporation is the primary cause of the phenomenon. This paper presents a new model to estimate the severity of plastic shrinkage cracking, based on the initial setting time and the amount of the evaporated water from within the concrete bulk. A number of experiments were performed under controlled ambient conditions, during which the water-cement ratio, cement type, and the dosage of superplasticizer were altered. The results, alongside those reported by other researchers, were utilized to check the validity of the proposed model. According to the outcomes, the model could predict the cracking severity of the tested concretes with a relative precision.

Place, publisher, year, edition, pages
Institution of Civil Engineers (ICE), 2021
Keywords
plastic shrinkage, cracks, cracking, initial setting, dormant period, evaporation, bleeding, modelling, shrinkage
National Category
Other Materials Engineering
Research subject
Building Materials
Identifiers
urn:nbn:se:ltu:diva-73172 (URN)10.1680/jmacr.19.00279 (DOI)000619674900004 ()2-s2.0-85101473102 (Scopus ID)
Funder
Svenska Byggbranschens Utvecklingsfond (SBUF)
Note

Validerad;2021;Nivå 2;2021-03-25 (alebob)

Available from: 2019-03-12 Created: 2019-03-12 Last updated: 2021-03-25Bibliographically approved
Täljsten, B., Paulsson, B., Popescu, C., Bagge, N., Nilforoush, R., Emborg, M., . . . Elfgren, L. (2020). Assessment of prestressed concrete bridges - challenges. In: Jan Bień, Jan Biliszczuk, Paweł Hawryszków, Maciej Hildebrand, Marta Knawa-Hawryszków, Krzysztof Sadowski (Ed.), IABSE Symposium, Wroclaw 2020: Synergy of Culture and Civil Engineering – History and Challenges. Paper presented at IABSE Symposium “Synergy of Culture and Civil Engineering – History and Challenges”, 7-9 October, 2020, Wrocław, Poland (pp. 487-494). Zürich: International Association For Bridge And Structural Engineering (IABSE)
Open this publication in new window or tab >>Assessment of prestressed concrete bridges - challenges
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2020 (English)In: IABSE Symposium, Wroclaw 2020: Synergy of Culture and Civil Engineering – History and Challenges / [ed] Jan Bień, Jan Biliszczuk, Paweł Hawryszków, Maciej Hildebrand, Marta Knawa-Hawryszków, Krzysztof Sadowski, Zürich: International Association For Bridge And Structural Engineering (IABSE) , 2020, p. 487-494Conference paper, Published paper (Refereed)
Abstract [en]

Prestressed concrete bridges are important parts of our infrastructure. They are susceptible to different kinds of deterioration processes. Examples of damages and deficiencies are cracking, corrosion, voids, bond loss, reduction of cover layer, delamination, fatigue and loss of stiffness and strength. This necessitates methods to continuously assess their condition in order to avoid problems that might lead to shorter service life or reduction of structural integrity. Many of the existing prestressed bridges in Europe are now approaching their design life length. However, with proper and continuous inspection, monitoring and assessment, we may plan proactive maintenance and the structural safety can be assured or – if necessary - increased. This will save both money and decrease the environmental impact of the structure.

Place, publisher, year, edition, pages
Zürich: International Association For Bridge And Structural Engineering (IABSE), 2020
Keywords
Prestressed Concrete Bridges, Challenges, Safety, Corrosion, Fatigue, Assessment, Monitoring, Repair, Strengthening
National Category
Other Civil Engineering Other Materials Engineering
Research subject
Structural Engineering; Building Materials
Identifiers
urn:nbn:se:ltu:diva-81135 (URN)2-s2.0-85103445841 (Scopus ID)
Conference
IABSE Symposium “Synergy of Culture and Civil Engineering – History and Challenges”, 7-9 October, 2020, Wrocław, Poland
Funder
Swedish Transport Administration, BBT 2017-011, TRV 2018/28332, ID 6686
Note

ISBN för värdpublikation: 978-3-85748-169-7

Available from: 2020-10-14 Created: 2020-10-14 Last updated: 2023-09-05Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-3997-3083

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