Blar i NTNU Open på forfatter "Machner, Alisa"
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Chloride-binding capacity of hydrotalcite in cement pastes containing dolomite and metakaolin
Machner, Alisa; Zajac, Maciej; Ben Haha, Mohsen; Kjellsen, Knut Ose; Geiker, Mette Rica; De Weerdt, Klaartje (Journal article; Peer reviewed, 2018)In this study, we investigated well-hydrated cement pastes containing dolomite and metakaolin cured at 38 °C or 60 °C, which were exposed to NaCl or CaCl2 solutions of various concentrations. We determined the chloride-binding ... -
Critical investigation of TGA sample preparation for composite cements
Machner, Alisa; Bussetti, Lucie; Geiker, Mette Rica; De Weerdt, Klaartje (Chapter, 2015)Thermogravimetric analysis (TGA) is a frequently used technique to investigate the phase assemblages of hydrated cements. However the obtained results are sensitive to the sample preparation. A commonly used technique for ... -
Impact of leaching on chloride ingress profiles in concrete
Bjørndal, Marie (Master thesis, 2019)Kloridinitiert armeringskorrosjon er en av hovednedbrytningsmekanismene for armerte betongkonstruksjoner. Klorider trenger igjennom betongoverdekningen over tid og forårsaker korrosjon når de når et kritisk kloridinnhold ... -
Investigation of the products of the dolomite reaction in Portland cement pastes
Machner, Alisa; Zajac, Maciej; Ben Haha, Mohsen; Kjellsen, Knut Ose; Geiker, Mette Rica; De Weerdt, Klaartje (Chapter; Conference object; Peer reviewed, 2017)The formation of potentially deleterious reaction products from the reaction of dolomite fines in Portland cement pastes was investigated. It was shown that the reaction of dolomite fines did not follow the commonly accepted ... -
Limitations of the hydrotalcite formation in Portland composite cement pastes containing dolomite and metakaolin
Machner, Alisa; Zajac, Maciej; Ben Haha, Mohsen; Kjellsen, Knut Ose; Geiker, Mette Rica; De Weerdt, Klaartje (Journal article; Peer reviewed, 2018)This study focuses on the reaction of dolomite powder in combination with metakaolin in Portland composite cement pastes. We studied paste samples cured at 20 °C, 38 °C, and 60 °C for up to 1 year. In these systems, the ... -
pH-dependence of chloride binding in ordinary Portland cement
Hemstad, Petter (Master thesis, 2018)A new method for artificially leaching hydrated cement paste and studying how lowered pH in the pore solution affects chloride binding has been developed. Hydrated cement paste was exposed to a NaCl-solution before being ... -
Portland metakaolin cement containing dolomite or limestone – Similarities and differences in phase assemblage and compressive strength
Machner, Alisa; Zajac, Maciej; Ben Haha, Mohsen; Kjellsen, Knut O.; Geiker, Mette Rica; De Weerdt, Klaartje (Journal article; Peer reviewed, 2017)The scarceness of high-quality limestone obliges the cement industry to consider alternative supplementary cementitious materials (SCMs) for the production of blended cements. This study investigated the potential usage ... -
Stability of the hydrate phase assemblage in Portland composite cements containing dolomite and metakaolin after leaching, carbonation, and chloride exposure
Machner, Alisa; Zajac, Maciej; Ben Haha, Mohsen; Kjellsen, Knut Ose; Geiker, Mette Rica; De Weerdt, Klaartje (Journal article; Peer reviewed, 2018)To reduce CO2 emissions during the production of cement and to cope with increasing demands for concrete, and thereby cement, the cement industry needs to identify new supplementary cementitious materials. These new composite ... -
The effect of artificial leaching with HCl on chloride binding in ordinary Portland cement paste
Hemstad, Petter; Machner, Alisa; De Weerdt, Klaartje (Journal article; Peer reviewed, 2020)This study investigates how the pH in the pore solution influences the chloride binding in Portland cement pastes. Cement paste samples were exposed to NaCl, CaCl2 and HCl solutions. The mechanisms of changes in chloride ... -
Towards the Understanding of the pH Dependency of the Chloride Binding of Portland Cement Pastes
Machner, Alisa; Hemstad, Petter; De Weerdt, Klaartje (Journal article; Peer reviewed, 2018)Hydrated Portland cement paste exposed to a NaCl solution was acidified by adding HCl in small steps, gradually lowering the pH. The chloride binding of the cement paste changed as a function of the pH. For the range of ...