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Ursenbacher Thierry

Professeur HES associé

Main skills

Optimisation de système énergétique

Main contract

Professeur HES associé

Phone: +41 26 429 66 63

Desktop: HEIA_D10.17

Haute école d'ingénierie et d'architecture de Fribourg
Boulevard de Pérolles 80, 1700 Fribourg, CH

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Completed

Micro-Production (bio)Chimique intégrée avec un microréacteur low-cost intégrant un catalyseur

AGP

Role: Collaborator

Financement: HES-SO Rectorat; Microtechnologies appl.; FR - EIA - ITIN - Chimie industrielle et appliquée; FR - EIA - ITIN Général institut; VS - Institut Technologies du vivant; FR - EIA - Général école Ra&D; FR - EIA - ITIN - Chimie industrie

Description du projet : Ce projet propose la réalisation d'une micro-unité low-cost, à même de réaliser non seulement un « screening » rapide de différentes réactions, mais aussi un « scale-up » et une Micro-Production. L'utilisation d'un microréacteur doit permettre de minimiser les coûts au vu des faibles volumes engagés et des quantités raisonnables de matériel nécessaire. Le couplage réaction/analyse, la flexibilité en termes de configuration et de temps de réalisation ainsi que l'efficacité des transferts de matière et de chaleur sont des facteurs qui permettent un gain de temps très appréciable lors des essais visant à l'optimisation des conditions de réaction. Finalement, il doit être possible d'intégrer dans cette unité un catalyseur enzymatique.

Research team within HES-SO: Crelier Simon , Banakh Oksana , Ursenbacher Thierry , Aebischer Jean-Nicolas , Audriaz Michel , Naef Olivier , Dufresne Rémy , Charmet Jérôme , Moutarlier Nicolas , Raetzo Raphaël , Schaller Renaud , Laux Edith

Durée du projet: 01.01.2008 - 31.08.2010

Montant global du projet: 536'750 CHF

Statut: Completed

2022

Shotcrete 3DCP projection angle and speed optimization :

Conference ArODES

Experimental Approaches and Theoretical Modelling

Benjamin Galé, Thierry Ursenbacher, Agnès Petit, Vincent Bourquin

Proceedings of the 3rd RILEM International Confernece on Cocnrete and Digital Fabrication, 27-29 June 2022, Loughborough, UK; RILEM Bookseries

Link to the conference

Summary:

Shotcrete has been lately used for additive manufacturing because of the high versatility of this method and possibility to integrate reinforcement. However, it is known that shotcrete generates waste due to rebound. To minimize the waste, the spraying process needs to be optimized. This work shows the optimization of wet-mix shotcrete from both experimental and theoretical sides for the use in shotcrete 3D concrete printing (S-3DCP). A better control must be reached to reduce the waste from rebounds and for improving the concrete mechanical properties. A strategy to reduce the waste coming from rebounds is to narrow the concrete jet angle, accelerate all particles at the same speed and ensure a homogeneous sprayed material across the jet. Several types of nozzles have been developed and assessed to ensure high mechanical properties, minimal waste and homogeneous spraying. The classic value of the cone angle is about 15°. The nozzle developed and assessed in experiments managed to reduce it to 8° by optimizing the air inlet and the internal shape of the nozzle, and it was reduced to 2.5° by using an additional air intake. A model of S-3DCP using aerodynamics (drag force), considering both paste and aggregate phases and the rheological properties of concrete has been developed to evaluate the influence of different parameters. The best configuration between the nozzle shape, air settings (pressure and flowrate) and concrete settings (aggregate distribution, paste composition and mass flowrate) allowed to find an optimum for the concrete jet speed. The speed of the spray has a major influence on the cohesion between the concrete layers. Using optimized nozzle geometry and particle velocity, the improvement in strength performance has been measured from 20–25%. The model has been verified by reproducing experimental conditions and comparing speed results.

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Ursenbacher Thierry

Professeur HES associé

Main skills

Mécanique des fluides

Aérodynamique

Transfert de chaleur

Hydraulique

Optimisation de système énergétique

Professeur HES associé