Rheo-physics and shaping of fresh cement-based materials by Dr. Nicolas Roussel

Описание: Speaker: Dr. Nicolas Roussel, Research Director, Laboratoire Navier, Université Gustave Eiffel, France

Title: Rheo-physics and shaping of fresh cement-based materials

Interest in the rheological properties of fresh cement-based materials has steadily grown in the last couple decades due to the development of new automated concrete shaping processes. These “large-scale” additive manufacturing technologies are progressively shifting the usual rheological requirements of standard cement-based materials.

In the first part of this lecture, we will go through the physical and chemical origin of fresh cement-based materials macroscopic properties and their evolutions with time. We will show the dominant role of colloidal attractive forces on short time scales. We will moreover describe, on longer time scales, the reversible macroscopic consequences of the non-reversible cement hydration reaction.

In the second part, we will describe the way these properties dictate the outcome of both typical formative and recent additive shaping processes. We will in parallel revisit these processing technologies under the light of the central role played by gravity-induced stresses and their competition with yield stress and its time evolution. This will allow us to deal with the exact extent of the adjective “large-scale”.


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