SPP 2005© Uli Steiger / Mechtcherine, Haist, Garrecht

The processing of cement-based building materials is the technological core in the construction and maintenance of structures. Although formability in the fresh state offers almost unlimited possibilities for shaping the structures and development of new construction techniques, today only a tiny fraction of this enormous potential is used. Lack of a scientific framework for mastering rheology-based processes is a major obstacle for developing novel and highly innovative construction technologies, such as 3D printing with concrete, as well as for solving current technical challenges, such as pumping to extreme heights.

 

The reason behind the shortcomings of the rheological framework is the extremely high complexity of the cementitious systems. The high chemical reactivity of mineral binders leads, only seconds after the addition of water, to changes in the particle morphology, the dissolution of larger and formation of new nanoscale particles, and severe alteration in the chemistry of the carrier liquid. Both the newly formed nanoparticles and the carrier liquid interact in turn with granular raw materials up to several centimetres in size (multiscale). Also, cementitious suspensions are always complex multi-phase systems which contain organic admixtures and air pores in addition to water and various mineral particles. Finally, casting and processing of cementitious materials are carried out under an enormous range of deformation rates, which result in extremely high demands of characterisation and simulation methods.

 

The goal of the priority program is to ascertain and describe the scientific fundamentals for understanding and consecutively designing rheology-based construction processes as well as for developing innovative, sustainable building materials and associated pioneering processing technologies. Further goals are:

  • Investigation and analysis of the interactions of reactive (hydrating) particles on the microscale, including the quantification of influences (morphology, chemistry, temperature, time, etc.) and the modelling of particle interactions;
  • Development of strategies and concepts for the description of deformation and flow processes of fresh concrete based on microscale processes and taking into account mesoscopic processes (segregation, de-aeration, fibre distribution, etc.);
  • Analysis and comprehension of the relevant processing operations of fresh concrete (transport, casting, compaction, finishing, etc.) using scientific tools and methods of rheology;
  • Elaboration of the measurement methods for the detection of the fresh concrete behaviour at different levels of consideration and various claim scenarios;
  • Development of constitutive material relationships for fresh concrete to simulate the phases and actions of processing.

Contact


TU Dresden
Institute of Construction Materials
01062 Dresden, Deutschland
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