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From cement grout to concrete scale: a study of superplasticizer-design-controlled thixotropy to match SCC application requirements



Author(s): L. Ferrari, P. Boustingorry, A. Pineaud, L. Bonafous
Paper category: Conference
Book title: Rheology and processing of Construction Materials – 7th RILEM International Conference on Self-Compacting Concrete and 1st RILEM International Conference on Rheology and Processing of Construction Materials
Editor(s): Nicolas Roussel and Hela Bessaies-Bey
Print ISBN: 978-2-35158-137-7
e-ISBN: 978-2-35158-138-4
Publisher: RILEM Publications SARL
Pages: 285-292
Total Pages: 8
Language: English


Abstract: 
Self compacting concrete is now widespread in precast applications due to its ability to fill even complex formworks without vibration. This study shows how properties like long distance self levelling, segregation or stickiness may be influenced by superplasticizers through the interaction with thixotropy.

Low shear rate rheological measurements were performed on concrete equivalent grouts to monitor the influence of polycarboxylate superplasticizers on structure buildup rates. The thixotropy description initially developed by N. Roussel was applied to steady state flow curves in order to model the influence of admixtures.

Specifically designed concrete channel and box-flow tests were developed in order to assess workability and formwork-filling retention while applying as little energy as possible to the material. The trends observed at the rheometer scale were confirmed at larger scale showing that structure build-up kinetics have a major influence on concrete placing and that superplasticizers may partly control it. A new superplasticizer allowing faster and more homogeneous formwork filling properties was developed and successfully tested on a full scale.


Online publication: 2013
Publication Type: full_text
Public price (Euros): 0.00