Blar i Institutt for konstruksjonsteknikk på forfatter "Lindgård, Jan"
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Alkali Aggregate Reactions (AAR) in concrete. The Norwegian endeavour during more than 3 decades of research
Wigum, Børge Johannes; Lindgård, Jan; De Weerdt, Klaartje; Pedersen, Bård Magne; Rønning, Terje F. (Chapter, 2022)It is now more than 80 years since Alkali Aggregate Reactions (AAR) first were reported as a deleterious deterioration mechanism in concrete. In Norway, AAR was recognised in the late nineteeneighties. Norwegian experience ... -
Alkali metal distribution in composite cement pastes and its relation to accelerated ASR tests
Hemstad, Petter; Zuschlag, Pamela; Kjellemyr, Petter; Lindgård, Jan; Kjellsen, Knut O.; Rønning, Terje; Justnes, Harald; Maciej, Zajac; Haha, Mohsen Ben; Weerdt, Klaartje de (Peer reviewed; Journal article, 2023)Accelerated testing of alkali silica reaction (ASR) in concrete at elevated temperatures of 38 and 60 °C has an unknown impact on the alkali metal distribution in the cement paste. This paper investigates how the alkali ... -
Alkali-silica reaction (ASR)-performance testing: Influence of specimen pre-treatment, exposure conditions and prism size on alkali leaching and prism expansion
Lindgård, Jan; Thomas, Michael D.A.; Sellevold, Erik Johan; Pedersen, Bård; Andiç-Çakır, Özge; Justnes, Harald; Rønning, Terje F. (Journal article; Peer reviewed, 2013)Whether or not concrete prism tests developed for assessment of alkali–silica reactivity of aggregates might be suitable for general ASR performance testing of concrete has been evaluated. This paper discusses how variations ... -
Alkali–silica reaction (ASR)—performance testing: Influence of specimen pre-treatment, exposure conditions and prism size on concrete porosity, moisture state and transport properties
Lindgård, Jan; Sellevold, Erik Johan; Thomas, Michael D.A.; Pedersen, Bård; Justnes, Harald; Rønning, Terje F. (Journal article; Peer reviewed, 2013)Whether or not concrete prism tests (CPTs) developed for assessment of alkali–silica reactivity of aggregates might be suitable for general ASR performance testing of concrete has been evaluated. This paper presents the ... -
Determination of the pH and the free alkali metal content in the pore solution of concrete: Review and experimental comparison
Plusquellec, Gilles; Geiker, Mette Rica; Lindgård, Jan; Duchesne, Josée; Fournier, Benoit; De Weerdt, Klaartje (Journal article; Peer reviewed, 2017)The durability of concrete is affected by the pH of its pore solution, which is linked to the free alkali metal content. This paper starts with a literature review of methods for determining the pH and/or the free alkali ... -
Determining alkali content in ASR performance-tested concrete
Kermit, Peter Holiman (Master thesis, 2017)Alkali silica reation (ASR) is a common deterioration mechanism of concrete. During ASR, reactive aggregate containing silicon oxide (SiO2) can react with the alkaline fluid in the concrete pores. To test whether a concrete ... -
Determining alkali leaching during accelerated ASR performance testing and in field exposed cubes using cold water extraction (CWE) and μXRF
Lindgård, Jan; Østnor, Tone Anita; Fournier, Benoit; Lindgård, Øyvind; Danner, Tobias; Plusquellec, Gilles; De Weerdt, Klaartje (Journal article; Peer reviewed, 2018)Considerable leaching of alkali metals was documented, both in concrete samples exposed to accelerated laboratory testing and field samples. CWE allowed to quantitatively determine the free alkali metal profiles as a ... -
Determining the free alkali metal content in concrete – Case study of an ASR-affected dam
Plusquellec, Gilles; Geiker, Mette Rica; Lindgård, Jan; De Weerdt, Klaartje (Journal article; Peer reviewed, 2018)In concrete affected by alkali–silica reaction (ASR), aggregates react in the high pH environment and cause deleterious expansion and cracking of the concrete. Leaching of alkali metals from the concrete might therefore ... -
Frost dilation measurements on concrete cores from a dam with ASR
Jacobsen, Stefan; Lindgård, Jan; Fritz, Leonie (Chapter, 2008)In order to evaluate length change measurements to determine damage in concrete due to both ASR and internal frost attack, concrete cores drilled from a 25 year old dam with slight ASR and some surface frost damage were ... -
Fundamental study on ASR kinetics - effect of temperature on aggregate reactivity and pore-water composition
De Weerdt, Klaartje; Hemstad, Petter; Justnes, Harald; Østnor, Tone Anita; Rønning, Terje F.; Lindgård, Jan (The International Conference on Alkali-Aggregate Reaction (ICAAR);Theme 4, Chapter, 2021) -
Investigations on the feasibility of the CWE method to verify potential alkali release from aggregates in Norwegian field concrete
Danner, Tobias; De Weerdt, Klaartje; Pedersen, Bård Magne; Lindgård, Jan (Chapter, 2021)Concrete elements exposed for 26 years to seawater spray and deicing salts along a road close to Sandnessjøen in Norway were investigated. Concrete cores from 4 elements with different binder compositions (A: 100 % Portland ... -
Pyrrhotite in concrete aggregate. Introduction to mechanism, damage potential and ongoing research
Lindstad, Hallvard; Lindgård, Jan; Pedersen, Bård Magne; Wigum, Børge Johannes; Aasly, Kurt; Ullnæss, Inger Lise; Oberhardt, Nikolas; De Weerdt, Klaartje (Chapter, 2022)Pyrrhotite is an iron sulfide which when present in concrete aggregate may lead to expansive reactions, cracks and finally disintegration of the concrete. This potential risk when using aggregates containing sulfides in ... -
Relative humidity measurements in concrete
Hepsøe, Per Martin (Master thesis, 2017)A commonly used way to monitor the concrete s moisture condition is to measure Relative humidity (RH). Measuring relative RH in concrete, and understanding the underlying mechanisms are complex tasks. Field measurements ... -
Sample preparation and the pilot testing of an oxygen consumption test that assesses the extent of pyrrhotite oxidation in sulfide-bearing concrete aggregates
Muhyiddin, Yahya (Master thesis, 2023)Når betongtilslag inneholder magnetkis, et mineral som består av jern og svovel, kan dette føre til betydelige skader på betongkonstruksjoner. I 2016 ble en kanadisk testprosedyre introdusert. Målet med denne testprosedyren ...