International Concrete Abstracts Portal

Title: Influence of Different Secondary Raw Materials on the Granulated Blast-Furnace Slag Reaction

Author(s): W. Brameshuber and P. Schriider

Publication: Special Publication

Volume: 202

Issue:

Appears on pages(s): 245-266

Keywords: activator; cement paste; composite cement; granulated blast-furnace slag; hydration; strength development; supplementary cementing materials

Date: 8/1/2001

Abstract:
For the practical use of granulated blast-furnace slag as a clinker substitute, the addition of an activator is neccessary, in order to ensure that a sufficient early and ultimate strength will be reached. Up to now, portland cement has been the most common type of activator for granulated blast-furnace slag. The addition of portland cement leads to the activation of the granulated blast-furnace slag either on an alkaline or, to a minor extent, on a sulphate basis. Materials which prevent the obstruction of the latent hydraulic reaction by a close gel layer of reaction products work as an activator. In this paper, the influence of different fine-grained additives, e. g. fly ash or cement kiln dust, on the granulated blast-furnace slag reaction and the strength development is discussed. The investigations showed that it is basically possible to manufacture composite cement with a high content of granulated blast-furnace slag by using industrially by-products. These cements shows particularly a higher early strength than the reference cement dependent on the composition respectively to the addition. The reactivity of the blast-furnace slag is strongly influenced by the chemical composition of the addition or activator but also by the mineralogical and chemical composition of the blast-furnace slag.