Abstract: A method is provided for determining a mix proportion of an alkali activated concrete, AAC, mixture for a set of desired physical properties of the AAC, and for a dry bulk volume of one or more coarse aggregates and a fine aggregate per unit volume of AAC. The method includes determining (202) a mix proportion of an alkali activated paste, AAP, mixture from the set of desired physical properties of the AAC based on a predetermined relationship (210) between the set of desired physical properties of the AAC and the mix proportion of the AAP mixture. The AAP mixture has one or more precursors, one or more chemical compounds of an alkali activator, and water according to the determined mix proportion of the AAP.

Abstract: A computer-implemented method is provided (200) for determining one or more physical properties of alkali activated concrete, AAC, from a mix proportion (201) of an AAC mixture. The AAC mixture has one or more precursors, one or more chemical compounds, and water according to the mix proportion. The computer implemented method includes obtaining (210) one or more control factors (211-215) from the mix proportion of the AAC mixture, where the one or more control factors are indicative for one or more reaction mechanisms in the AAC mixture; and determining (220) a compressive strength (225) of the AAC based on the one or more control factors of the AAC mixture by means of a machine learning model (224). The machine learning model is trained by a training dataset (221) having one or more control factors of a plurality of AAC mixtures with different mix proportions; and corresponding compressive strengths of the AAC obtained by setting and hardening of the respective AAC mixtures.

Abstract: The invention relates to a method for layer-by-layer deposition of concrete, in particular of concrete using a rapidly hydrating cementitious binder. A first flow and a second flow are supplied to a mixer to obtain extrudable concrete. The pH of the second flow is larger than the pH of the first flow. The first flow comprises a retarded cementitious binder obtainable by mixing a cementitious binder with a retarder comprising boron and sodium. The retarder allows to increase the setting time of the cementitious binder and allows to influence the pH of the first flow in such a way that the pH of the first flow is lower than the pH of a flow equal to the first flow but comprising the cementitious binder instead of the retarded cementitious binder. The second flow comprises a carrier material. The volume fraction of the carrier material is at least 20 vol % of the second flow.

Abstract: The present disclosure relates to the use of a polymer as chemical admixture, in particular, as superplasticizer, in a cementitious material. The polymer has a backbone structure provided with a plurality of negatively charged groups and provided with a plurality of side chains. at least part of the side chains comprises a pendent group having a sterically hindered amine. The disclosure further relates to a cementitious composition comprising a chemical admixture, in particular, a superplasticizer.

Abstract: The invention relates to an admixture for a cementitious material suitable to influence the rheological properties of the cementitious material. The admixture includes a compound having a backbone chain provided with at least one first functionality and at least one second functionality. The at least one first functionality is adapted to adsorb to the cement particles of the cementitious material. The at least one second functionality is adapted to respond to an external trigger signal of an electric field, a magnetic field or an electromagnetic field, thereby influencing the rheological properties of the cementitious material. The rheological properties are influenced by influencing the interaction of the at least one first functionality with the cement particles and/or by influencing the interparticle interaction between the cement particles. The invention further relates to a cementitious material including such admixture.

Abstract: The invention relates to a method for layer-by-layer deposition of concrete by providing extrudable concrete. A first flow comprising a binder material and water and a second flow comprising a carrier material, an additional component and water are mixed in a static mixer to form a third flow of extrudable concrete. The material of the second flow has a shorter initial setting time than the material of the first flow. The first flow has a first viscosity V1 and the second flow has a second viscosity V2 so that the ratio V1/V2 ranges between 1/40 and 40. The third flow has a viscosity larger than the viscosity of the first flow and the second flow and a yield stress larger than the yield stress of the first flow and the second flow. The material of the third flow has an initial setting time shorter than initial setting time of the first flow. The invention further relates to a system to extrude concrete, in particular for layer-by-layer deposition of concrete.

Abstract: The invention relates to an admixture for a cementitious material suitable to influence the rheological properties of the cementitious material. The admixture comprises a compound having a backbone chain provided with at least one first functionality and at least one second functionality. The at least one first functionality is adapted to adsorb to the cement particles of the cementitious material. The at least one second functionality is adapted to respond to an external trigger signal of an electric field, a magnetic field or an electromagnetic field, thereby influencing the rheological properties of the cementitious material. The rheological properties are influenced by influencing the interaction of the at least one first functionality with the cement particles and/or by influencing the interparticle interaction between the cement particles. The invention further relates to a cementitious material comprising such admixture.