Interactions between Superplasticizer and Release Agents at the Concrete/Formwork Interface
- 1 Laboratoire Génie Civil et géo-Environnement (LGCgE)—Lille Nord de France, IUT de Béthune, Rue de l’Université, Béthune, France
- 2 Laboratoire Génie Civil et géo-Environnement (LGCgE)—Lille Nord de France, IUT de Béthune, Rue de l’Université, Béthune, France
- 3 Laboratoire Génie Civil et géo-Environnement (LGCgE)—Lille Nord de France, IUT de Béthune, Rue de l’Université, Béthune, France
- 4 Université de Toulouse, INP, LCA (Laboratoire de Chimie Agro-Industrielle), ENSIACET, Allée Emile Monso, Toulouse, France
- 5 Centre de Recherche Lafarge, Rue du Montmurier, St Quentin Fallavier, France
Abstract
Improving the knowledge of rheological and tribological characteristics of fresh concrete is important to contribute to the progress of construction sites and the final quality of the work. The objective of this study is to identify the effect of a superplasticizer based on polycarboxylic ether on the tribological behavior of fresh concrete at the concrete/formwork and concrete/oil/formwork interfaces. Friction tests on fresh concrete were carried out using a plan/plan tribometer. In order to study the behavior of the superplasticizer close to the formwork, three concretes with 30% of paste and different dosage of superplasticizer were formulated. The results show that the increase of the dosage of superplasticizer reduces the friction stress. The properties of the superplasticizer generate a deflocculating action of concrete grains and lead to a stabilisation of the soap-oil micellae present in the vicinity of the formwork. Thus, the efficiency of superplasticizer depends on the quantity of fines, on the quantity of soap formed and so, on the release agent formulation.
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