Lafarge

Holcim Technology Ltd

Fabrice Toussaint

Pierre-Henri Jezequel

Rémi Barbarulo

Christian Blachier

Cedric Roy

Fabien Perez

Cédric Roy

Helene Lombois-Burger

Laurent Ferreira

Gérard Molines

Cedric Juge

Vivien Esnault

Gërard Molines

Abdellaziz Labyad

Remi Barbarulo

Gerard Molines

David Rinaldi

Kevin Carnevale

Benoît Mathonier

Cédric Juge

Hélène Lombois-burger

A method of placing a flowable construction material including a hydraulic binder for building structural components layer-by-layer, such as for 3D concrete printing, the method including preparing a fresh flowable construction material made of Portland cement, fine limestone filler materials, fine sands, water, and water reducing admixture and possibly a set or hardening accelerating admixture, conveying the flowable construction material to a deposition head, placing the construction material through an outlet of the deposition head in order to form a layer of construction material, before placing the construction material, adding a rheology-modifying agent to the construction material so that the placed material has an increased yield stress when compared to the material during the conveying step.

Online control of rheology of building material for 3D printing

A hydraulic binder includes, as percentage by mass: from 17 to 55% of a Portland cement, the particles of which have a D50 of from 2 &#x3bc;m to 11 &#x3bc;m; at least 5% of silica fume; from 36 to 70% of a mineral addition A1, the particles of which have a D50 of from 15 to 150 &#x3bc;m; the sum of these percentages being from 80 to 100%; the sum of the percentages of cement and of silica fume being greater than 28%; the mineral addition A1 being selected from slags, pozzolanic additions or siliceous additions such as quartz, silico-calcareous mineral additions, calcareous additions such as calcium carbonate or mixtures thereof.

Ultra-high performance concretes having a low cement content

A method for controlling at least one workability parameter of a concrete contained in the container of a mixer with a non vertical rotational axis, includes making the container turn at least at least two different rotational speeds; determining, for each of the rotational speeds, a rotary drive torque C of the container, a value of shear stress r of the concrete and a speed gradient &#x3b3; of the concrete according to the following relationships: &#x3c4;=T(&#x3c9;)&#xb7;C and &#x3b3;=G(&#x3c9;). &#x3c9; where T and G are predetermined functions; determining a relationship of variation of shear stress &#x3c4; according to the speed gradient &#x3b3; by extrapolation and/or approximation from the determined values; and providing an indication of the workability parameter of the concrete based on the relationship variation.

Method for controlling a workability parameter of a concrete in a mixer

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Saint Quentin Fallavier, France

Fabrice Toussaint