Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Improved workability of calcia free alumina binder Alphabond for non-cement castables
Alphabond is a hydratable alumina, which is used as a binder in non-cement castables, e.g for steel ladle and other applications. Introduced in the 1990's, the market interest in this calcia free hydraulic binder has considerably increased over the last few years. Alphabond behaves similar to high purity calcium aluminate cement based castables with respect to working time, setting time, water demand and flow properties, it had some unique characteristics that require special attention during application. Generally, dense castables using Alphabond have required extended mixing time to fully 'wet out'. A new and improved Alphabond binder (Alphabond 500) is presented, which remarkably reduces the mixing differences as compared to cement bonded castables. It reduces the required mixing time to fully 'wet out' to about 120 seconds, a level that is comparable to usual low cement castables. The different drying behaviour of Alphabond castables compared to cement castables has been investigated. The advantages in hot properties of calcia free Alphabond spinel forming castables are discussed. As demonstrated by the test castables, the flow and set behaviour of Alphabond 500 is comparable to that for the established Alphabond 300 product. Therefore to cope with their demanding mixing and placing requirements, Alphabond 500 is expected to quickly become the product of choice in castables for on-site casting. Alphabond as calcia free hydratable alumina binder offers the advantage of robust setting behaviour with regard to temperature and improved hot properties, especially for silica containing spinel forming castables. This offers the refractory engineer new opportunities for an advanced generation of castable developments for monolithic steel ladle lining. The drying of Alphabond castables requires special attention because of the inherent de-hydration behaviour of hydratable alumina. The water is released in a more narrow temperature range compared to cement bonded castables.
Improved workability of calcia free alumina binder Alphabond for non-cement castables
Alphabond is a hydratable alumina, which is used as a binder in non-cement castables, e.g for steel ladle and other applications. Introduced in the 1990's, the market interest in this calcia free hydraulic binder has considerably increased over the last few years. Alphabond behaves similar to high purity calcium aluminate cement based castables with respect to working time, setting time, water demand and flow properties, it had some unique characteristics that require special attention during application. Generally, dense castables using Alphabond have required extended mixing time to fully 'wet out'. A new and improved Alphabond binder (Alphabond 500) is presented, which remarkably reduces the mixing differences as compared to cement bonded castables. It reduces the required mixing time to fully 'wet out' to about 120 seconds, a level that is comparable to usual low cement castables. The different drying behaviour of Alphabond castables compared to cement castables has been investigated. The advantages in hot properties of calcia free Alphabond spinel forming castables are discussed. As demonstrated by the test castables, the flow and set behaviour of Alphabond 500 is comparable to that for the established Alphabond 300 product. Therefore to cope with their demanding mixing and placing requirements, Alphabond 500 is expected to quickly become the product of choice in castables for on-site casting. Alphabond as calcia free hydratable alumina binder offers the advantage of robust setting behaviour with regard to temperature and improved hot properties, especially for silica containing spinel forming castables. This offers the refractory engineer new opportunities for an advanced generation of castable developments for monolithic steel ladle lining. The drying of Alphabond castables requires special attention because of the inherent de-hydration behaviour of hydratable alumina. The water is released in a more narrow temperature range compared to cement bonded castables.
Improved workability of calcia free alumina binder Alphabond for non-cement castables
Verbesserung der Verarbeitungseigenschaften des CaO-freien Binders Alphabond für zementfreie Feuerbetone
Kockegey-Lorenz, Rainer (Autor:in) / Büchel, Gunter (Autor:in) / Buhr, Andreas (Autor:in) / Aroni, Jose M. (Autor:in) / Racher, Raymond P. (Autor:in)
2004
5 Seiten, 4 Bilder, 3 Tabellen, 14 Quellen
Aufsatz (Konferenz)
Englisch
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