Browsing NTNU Open by Author "Danner, Tobias"
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25 years of field exposure of pre-cracked concrete beams; combined impact of spacers and cracks on reinforcement corrosion
Geiker, Mette Rica; Danner, Tobias; Michel, Alexander; Belda Revert, Andres; Linderoth, Oskar; Hornbostel, Karla (Peer reviewed; Journal article, 2021)The state of corrosion of three pre-cracked concrete beams was investigated after 25 years of marine exposure (atmospheric, tidal and submerged). The influence of inadequate plastic spacers was found to overrule the possible ... -
Acid Activation of Natural Rocks - A Case Study with Norwegian Anorthosite and Phosphoric Acid
Danner, Tobias; Justnes, Harald (SINTEF AS (ISBN starter med 978-82-14-);, Research report, 2021)Norway is rich in natural resources, especially different types of rocks that could potentially serve as raw material for alternative binder concepts like alkali activated binders or magnesium phosphate and magnesium hydroxy ... -
Calcareous smectite clay as a pozzolanic alternative to kaolin
Danner, Tobias; Norden, Geir; Justnes, Harald (Journal article; Peer reviewed, 2019)The hydration of cement pastes with addition of a kaolinite rich clay (Clay A) and a calcareous smectite rich clay (Clay B) was investigated with isothermal calorimetry, in-situ XRD, PXRD, TGA and EPMA. Portland cement was ... -
Carbonation and corrosion of steel in fly ash concrete, concluding investigation of five-year-old laboratory specimens and preliminary field data
Revert, Andres Belda; Danner, Tobias; Geiker, Mette Rica (Journal article; Peer reviewed, 2024)Carbonation development and reinforcement corrosion were investigated on concretes exposed for a five-year period at 90% RH, 20 ℃, and 5% CO2, and for a six-year period at natural carbonation. Portland cement-based binders ... -
Changes in cement paste during accelerated mortar bar testing for pyrrhotite containing aggregate
Weerdt, Klaartje de; Bagheri, Mahsa; Lindgård, Jan; Lindstad, Hallvard; Rodrigues, A.; Duchesne, J.; Fecteau, P.-L.; Haugen, Marit Kristin; Danner, Tobias; Wigum, Børge Johannes; Oberhardt, Nikolas; Aasly, Kari Aslaksen; Lothenbach, Barbara (Journal article; Peer reviewed, 2024)The accelerated mortar bar test (AMBT) for pyrrhotite (Fe1-xS) containing aggregates accelerates expansion using two regimes: Phase I, during which Fe1-xS oxidation to iron hydroxide is accelerated by bleach and storage ... -
Characterisation of calcined raw clays suitable as supplementary cementitious materials
Danner, Tobias; Norden, Geir; Justnes, Harald (Journal article; Peer reviewed, 2018)The potential use of two raw clays (Clay A: kaolin; Clay B: calcareous montmorillonite) as supplementary cementitious material (SCM) in blended cements was investigated. Cement replacement in mortars by 20% calcined Clay ... -
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 ... -
Durability aspects of cracks in concrete: field observations
Geiker, Mette Rica; Danner, Tobias; Hornbostel, Karla; Michel, Alexander (Chapter, 2019)The research presented in this paper briefly summarises findings from a project on impact of cracks on reinforcement corrosion within the Norwegian Public Roads Administration’s R&D program “Ferry-free coastal route E39”. ... -
Durability of cracked SFRC exposed to wet-dry cycles of chlorides and carbon dioxide – Multiscale deterioration phenomena
Marcos-Meson, Victor; Geiker, Mette Rica; Fischer, Gregor; Solgaard, Anders; Jakobsen, Ulla Hjorth; Danner, Tobias; Edvardsen, Carola; Skovhus, T.L.; Michel, Alexander (Peer reviewed; Journal article, 2020)This paper describes an experimental study that comprised the exposure of cracked SFRC members to wet-dry cycles involving chloride and carbon-dioxide for two years. Results indicate that corrosion of steel fibres occurs ... -
Evaluating the effect of mineralogy and mechanical stability of recycled excavation materials by Los Angeles and micro-Deval test
Adomako, Solomon; Thorstensen, Rein Terje; Akhtar, Naureen; Norby, Mariann; Engelsen, Christian John; Danner, Tobias; Barbieri, Diego Maria (Chapter, 2021)This paper presents the findings of the mechanical performance of recycled excavation materials (REM). The aim was to document the stable performance of REM and to suggest its suitability for unbound applications. Test ... -
Field Station Sandnessjøen, Effect of cracks in concrete after 25 years - Data report
Danner, Tobias; Belda Revert, Andres; Geiker, Mette Rica (Research report, 2020)Tre opprissede betongbjelker støpt med forskjellige bindemiddelsammensetninger ble undersøkt etter 25 års marin eksponering ved feltstasjon Sandnessjøen. Betongbjelkene ble undersøkt med tanke på effekten av riss på ... -
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 ... -
Long-term Influence of Concrete Surface and Crack Orientation on Self-healing and Ingress in Cracks – Field Observations
Danner, Tobias; Geiker, Mette Rica (Journal article; Peer reviewed, 2018)This paper presents results from investigations on the long-term influence of concrete surface and crack orientation on ingress in cracks. Five reinforced concrete structures from Norway exposed to either de-icing salts ... -
Mineralogical Sequence of Self-Healing Products in Cracked Marine Concrete
Danner, Tobias; Jakobsen, Ulla Hjorth; Geiker, Mette Rica (Journal article; Peer reviewed, 2019)Self-healing of cracked concrete beams after 25 years of marine exposure was investigated. The extent of self-healing and the chemical and mineralogical composition of the self-healing products were characterized, and ... -
NDT methods and sensors for existing concrete structures. Literature review
Popescu, Cosmin; Danner, Tobias; Myrdal, Roar; Lindgård, Jan; Revert, Andres Belda; Täljsten, Björn (SINTEF AS (ISBN starter med 978-82-14-), Research report, 2023) -
Non-destructive Test Methods for Corrosion Detection in Reinforced Concrete Structures
Hornbostel, Karla; Danner, Tobias; Geiker, Mette Rica (Peer reviewed; Journal article, 2020)Several inspection methods can be used to assess the corrosion state of steel reinforcement in concrete. Especially for periodical field surveys and monitoring, non-destructive testing (NDT) methods are to be preferred as ... -
Reactivity of Calcined Clays
Danner, Tobias (Doktoravhandlinger ved NTNU, 1503-8181; 2013:218, Doctoral thesis, 2013)With 3-5 billion tons cement-produced every year, the cement industry is today the third largest emitter of CO2 in the world after fossil-fuel based energy plants serving heating/cooling of buildings and combustion engines ... -
Recycled aggregates derived from excavation materials — mechanical performance and identification of weak minerals
Adomako, Solomon; Engelsen, Christian John; Danner, Tobias; Thorstensen, Rein Terje; Barbieri, Diego Maria (Journal article; Peer reviewed, 2022)The present study investigates the mechanical performance of recycled aggregates derived from excavation materials (REM). REM is blended with different quantities of recycled phyllite materials (RPM) and is investigated ... -
Self-healing and Chloride Ingress in Cracked Cathodically Protected Concrete Exposed to Marine Environment for 33 Years
Danner, Tobias; Hornbostel, Karla; Strømme, Øyvind; Geiker, Mette Rica (Research report, 2019)Cracks facilitate ingress of aggressive substances. Depending on the exposure, this might lead to early reinforcement corrosion initiation. Possible self-healing of cracks may reduce their long-term impact, and conditions ... -
µ-XRF – CHARACTERISATION OF CHLORIDE INGRESS AND SELF-HEALING IN CRACKED CONCRETE
Danner, Tobias; De Weerdt, Klaartje; Geiker, Mette Rica (Chapter, 2017)In this paper we illustrate the applicability of µ-XRF for investigations of chloride ingress and self-healing in cracked concrete. A cracked and an uncracked concrete core exposed to seawater for more than 30 years were ...