CEMENT WITH INTERGROUND ADDITIVES - CAPABILITIES AND ENVIRONMENTAL RELIEF .1.

The preparation of a European cement standard formed the stimulus in Germany for extending the range of different cements described in DIN 1164 to cover new cements with interground additives which have proved successful in other countries over a period of many years. These are primarily portland limestone cement and cements containing fly-ash from coal. They make it possible for the capabilities of the cement to be adapted more individually to the requirements of the cement consumer and building user, which vary quite considerably depending on the area of application. According to extensive tests - covering strengths and durability characteristics in concrete including resistance to frost and de-icing salts - cements with interground additives are at least equivalent to the locally comparable standard cements from the point of view of construction technology. This is true provided that the interground additives are selected carefully and are submitted to quality control, and provided that suitable manufacturing precautions are observed. They must be used in accordance with the relevant approval of the German Institute of Construction Technology and can be used in virtually all areas of application. Portland limestone cements often produce concretes with particularly favourable workability characteristics. The use of granulated blastfurnace slag, suitable coal fly-ash, or other pozzolanic or latent hydraulic substances, and the intergrinding of limestone makes it possible to lower the consumption of natural raw materials, to conserve landfill space and to save fuel energy for clinker production, and hence also to make appreciable reductions in the emission of CO2. This achieves another significant contribution towards lessening the burden on the environment during cement production.