Trade Journals for the Concrete Industry

With the objective of reducing discolorations in fair-faced concrete surfaces due to sedimentation, systematic investigations, inter alia, were carried out on the influences of the cement main constituents clinker, limestone, and blastfurnace slag on the rheological properties of cement paste and concrete as well as on their interactions with plasticizing concrete admixtures. The influences of compaction by vibration on the tendency of mortar and concrete to sedimentation was also an object of the investigations. Once the quantity of concrete admixture necessary for maximum plastification (saturation point dosage) had been exceeded, sedimentation phenomena occurred with almost all known discolorations in fair-faced concrete surfaces. Compaction by vibration, by way of contrast, only had an insignificant influence on sedimentation tendency. The determination of the saturation point and the saturation point dosage is explained as well as pointers are given in respect of concrete composition. The determination of the saturation point and saturation point dosage will be clarified and pointers given in respect of concrete composition.