Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
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Observations on dedolomitization of carbonate concrete aggregates, implications for ACR and expansion
Some carbonate aggregates used in concrete are unstable in a high alkaline solution, which is present also in pore solution of cement binder. This paper investigates the process of dedolomitization of carbonate aggregate rocks and mortar bars. Selected aggregates, limestone and dolostone are of high purity without reactive silica involvement confirmed by the XRD and the XRF. For the process of dedolomitization the effect of various temperatures, solutions and time was examined. In this investigation, measurements of expansion, optical and scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction were used. Te results indicate that the process of dedolomitization occurred not only in the NaOH solution but also in the water on the mortar bar with virgin dolostone aggregate. Elevated temperature, 60 °C, increased the rate of reaction. Furthermore, the rate of reaction significantly correlates with time, which has also been confirmed through the Rietveld analysis.
Observations on dedolomitization of carbonate concrete aggregates, implications for ACR and expansion
Some carbonate aggregates used in concrete are unstable in a high alkaline solution, which is present also in pore solution of cement binder. This paper investigates the process of dedolomitization of carbonate aggregate rocks and mortar bars. Selected aggregates, limestone and dolostone are of high purity without reactive silica involvement confirmed by the XRD and the XRF. For the process of dedolomitization the effect of various temperatures, solutions and time was examined. In this investigation, measurements of expansion, optical and scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction were used. Te results indicate that the process of dedolomitization occurred not only in the NaOH solution but also in the water on the mortar bar with virgin dolostone aggregate. Elevated temperature, 60 °C, increased the rate of reaction. Furthermore, the rate of reaction significantly correlates with time, which has also been confirmed through the Rietveld analysis.
Observations on dedolomitization of carbonate concrete aggregates, implications for ACR and expansion
Beobachtungen zur Entdolomitisierung von carbonatischen Betonzusatzstoffen, und Auswirkungen auf Alkali-Carbonat-Reaktionen und Ausdehnung
Princic, Tina (Autor:in) / Stukovnik, Petra (Autor:in) / Pejovnik, Stane (Autor:in) / De Schutter, Geert (Autor:in) / Bokan Bosiljkov, Violeta (Autor:in)
Cement and Concrete Research ; 54 ; 151-160
2013
10 Seiten, 23 Quellen
Aufsatz (Zeitschrift)
Englisch
Petrographie , Carbonat , Beton , Siliciumdioxid , Ausdehnungsmessung , Reaktionsgeschwindigkeit , Rietveld-Analyse , alkalische Lösung , Porenlösung , Kalkstein , hohe Reinheit , Temperatureinfluss , energiedispersive Spektrometrie , Temperaturerhöhung , Additiv , Dolomit , Alkali-Carbonat-Reaktion , Wasserabbinden von Zement , Rasterelektronenmikroskopie , Raumdimension
| British Library Online Contents | 2013
Mechanism of Dedolomitization and Expansion of Dolomitic Rocks
| British Library Online Contents | 1993
Mechanism of Dedolomitization and Expansion of Dolomitic Rocks
| Online Contents | 1993
Alkalicarbonate reactions and dedolomitization in concrete: silica, the elephant in the corner
| Online Contents | 2013