Interaction between cement and cellulose ether

• Antragsteller: Professor Dr.-Ing. Horst-Michael Ludwig
• Fachliche Zuordnung: Baustoffwissenschaften, Bauchemie, Bauphysik
• Förderung: Förderung von 2016 bis 2020
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 318749971

One of the major demands on future cementitious building materials is a dramatically reduced CO2 footprint. Development of new, more sustainable cements is an ongoing process that will lead to a broad variety of available cements. Establishing basic knowledge on the interaction of these sustainable cements with admixtures used in concrete and mortar production is a major challenge, which needs to be solved to bring sustainable cements into a wider field of application. Thus, the proposed project aims to investigate the interaction of Hydroxy Ethyl Methyl Cellulose (HEMC) with mortars based on sustainable cements. This will pave the way to an increased application of sustainable cements in the dry mortar industry. The investigated cements are selected to represent possible candidates for mortar production in the near future in China and in Europe. The new approach of the proposal is not only to bring Chinese and German research closer together, but also to widen the available analytical methods to bring fundamental new insights. Work packages include careful characterization and selection of raw materials (WP1), study of the basic interaction of HEMC with individual cementitious phases (WP2), and monitoring of the properties of sustainable mortars containing HEMC. Since HEMC are applied to dry mortars to increase water retention, one main aspect of the investigation focuses on the characterization of the mobility of water. Therefore, proton NMR relaxometry will be established in the working group at Tongji University (WP2). Complementary application of computed tomography to characterize the porosity of dry mortars at a 3D level will be developed at the Bauhaus-Universität. Another side effect of HEMC is the retardation of hydration. A basic understanding of the mechanism of retardation will be gained by investigations on the interaction of individual cement components (alite, aluminate, SCM-alite blends etc.) with HEMC and by separating into dissolution and precipitation processes (WP2). Characterization of mortar properties containing sustainable cements and HEMC will document performance and implement proper test methods (WP3). This approach will lead to the safe application of HEMC in dry mortars based on sound basic knowledge.

• DFG-Verfahren: Sachbeihilfen
• Internationaler Bezug: China
• Partnerorganisation: National Natural Science Foundation of China
• Kooperationspartner: Peiming Wang