Quantifications of Cements Composed of OPC, Calcined Clay, Pozzolanes and Limestone

Alternative and supplementary cementitious materials originate from different sources in nature and also from industrial productions. These materials came into focus again as their use can contribute substantially in the reduction of CO₂ during the manufacturing of cementitious materials. Also, the aspect of reducing the industrial residues by recycling is of substantial importance. As the addition of supplementary cementitious materials leads to different composite cements, it is highly necessary to determine the reaction behavior and their part during the hydration of the interground or interblended components. The different natural occuring materials from volcanic and sedimentary sources like clays and pozzolanic materials are available in high quantities and can be used. Due to their formation, the natural materials differ in their mineralogical and chemical composition and should be optimized for this application. Therefore, clays are often thermally treated to be activated, whereas other products are used without treatment with their original composition. Natural and industrial pozzolans also contain high amounts of amorphous phases which should be determined as they are partially reactive. As these materials do not contain typical cement minerals as calcium silicates and calcium aluminates, their reaction behavior is often caused by their amorphous contents. Other basic sources of mineral additions are coming of artificial sources and are mainly based on industrial residues coming from the processing of ores and include slags ore coming from energy production like fly ashes and bottom ashes. As these materials showing different compositions, their chemical and mineralogical phase relations must be determined also. Some of these supplementary cement additions are known for long times, and like latent hydraulic slags, others must be investigated and characterized newly. As these components vary in their reaction behavior, it is highly likely that their mineralogical quantification relates to their various properties and can be determined by different methods:Different artificial mixtures based on various OPCs with different additions of pozzolans, metakaolinite, limestone, anhydrite, and the quantification of their crystalline and amorphous contents will be demonstrated.