Project Details
Projekt
CO2-neutral biomass-based particle interactions for NET-ZERO Concretes (BIOMAC) - experiments and modeling
Subject Area
Construction Material Sciences, Chemistry, Building Physics
Term
since 2024
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 542200307
The aim of the BIOMAC project over the entire project duration is to research CO2-neutral concretes with environmentally friendly aggregates in combination with reactive binders, both based on biochar. The use of these CO2-negative residual materials in binder systems makes it possible to significantly reduce the CO2-footprint of future concrete systems to use them in an environmentally oriented construction industry. To meet necessary requirements, a comprehensive characterisation of the residual materials to be used as well as dedicated research into their interactions in the material composite will be carried out in this funding period. To achieve this goal with such low-strength starting materials, a packing density-optimized system, known from ultra-high-performance concretes, will be used as a basis. The loads that are transferred via the aggregates in normal concrete must be transferred via the concrete matrix of strength-forming material “ribbons”. These are composed of the strength-forming phases of the binder matrix and the contact zone (ITZ) between binder and biochar aggregate. To research these CO2-neutral systems, first the Portland cement will be partially substituted by reactive biochar ash at TU Darmstadt (TUDa) and the aggregates by CO2-negative biochar at the University of Kassel (UK), e.g., from the reducing combustion of residues from biogas production. In a joint step, these two approaches are combined. The research focus of TUDa is on the integration of biochar ashes as cement substitutes (SCM > 50 %) at the binder level and that of UK on the integration of the biochar aggregate in a binder system. The joint research focuses on the interactions in the ITZ. A modelling approach is being developed to predict the interactions and mechanical behavior of the ITZ between the matrix and biochar aggregates. To simulate the interaction between biochar (UK) and binder matrix (TUDa), experimental investigations are carried out to define the boundary conditions of the model. The model approach is based on a two-particle system, which culminates in a scalable BIOMAC-model-element. This will be transferred experimentally and simulatively to a multi-particle-system in collaboration with both project partners. Generated research data will be exchanged with the central project throughout the entire project duration to enable a comprehensive SPP life cycle assessment. The results this funding period form the basis for a concrete technology upscaling to a future and environmentally oriented BIOMAC system. Furthermore, the BIOMAC results are to be interlinked with the three modules of the SPP in next steps in order to identify possible paths for a new type of NET-ZERO concrete.
DFG Programme
Priority Programmes
Subproject of
SPP 2436:
Net-Zero Concrete
