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Rougeau P.,Studies and Research Center for the French Concrete Industry | Torrenti J.-M.,University Paris Est Creteil | Cussigh F.,VINCI Construction | Mai-Nhu J.,Studies and Research Center for the French Concrete Industry
European Journal of Environmental and Civil Engineering | Year: 2012

The construction sector is the largest industrial consumer of raw materials. Like all materials, concrete has an important role to play in sustainable development through its contribution to energy saving and durability of constructions. In this context, the performance-based approach to concrete durability appears to be one of the essential tools. It enables the use of new constituents and innovative concrete mixes, while improving the level of safety for the end user. The difficulty of the performance-related design method lies in choosing the threshold value. In the equivalent durability concept the main difficulty is to define the reference concrete. In this article we propose a methodology which can be used to take into account the variability of the concrete properties when a performance-based approach is applied. The proposed methodology allows the interest of using some statistical aspects to be discussed. © 2012 Taylor & Francis.

Soualhi H.,Cergy-Pontoise University | Kadri E.-H.,Cergy-Pontoise University | Ngo T.-T.,Cergy-Pontoise University | Bouvet A.,Cergy-Pontoise University | And 2 more authors.
Journal of Adhesion Science and Technology | Year: 2015

This study deals with the rheological properties of concrete mixtures incorporating various types of mineral additions as a partial replacement of cement in order to produce a low-impact environmental concrete. The control mixture contained only Portland cement as the binder, while the remaining mixtures incorporated binary cementitious blends of slag, limestone filler, and fly ash with different rates of replacement. After mixing, the plastic viscosity and yield stress of the concretes were evaluated at different slump values using a rheometer apparatus. The results showed that the type of mineral additions and the rate of substitution affect the rheological parameters of low-impact environmental concrete. Indeed, increasing the degree of substitution leads to an increase in the plastic viscosity of the concrete made with different types of additions used in this study. © 2015 Taylor & Francis.

Ngo T.-T.,Cergy-Pontoise University | Kadri E.-H.,Cergy-Pontoise University | Cussigh F.,VINCI Construction | Bennacer R.,Ecole Normale Superieure de Cachan
Canadian Journal of Civil Engineering | Year: 2011

The fresh concrete pumping parameters (viscous constant and yield stress) are determined by the steel-concrete interface friction (called boundary layer) that occurs during the fluid concrete flow through a pumping pipe. This friction depends on the properties of the formed boundary layer (composition and its thickness), which have a rigorous relationship with concrete composition parameters. The interface friction can be measured by an apparatus called a "tribometer". In this paper, a model is proposed to calculate the viscous constant by using the tribometrical measurements obtained from several concrete series by varying all the concrete composition parameters. The validation of this model with our experimental measurements (different concrete composition parameters) and those of Kaplan is proved. The model was found to satisfactorily predict the viscous constant of the fluid concrete with an error of no more than ±16%.

Soualhi H.,Cergy-Pontoise University | Kadri E.-H.,Cergy-Pontoise University | Ngo T.-T.,Cergy-Pontoise University | Bouvet A.,Cergy-Pontoise University | And 2 more authors.
Journal of Civil Engineering and Management | Year: 2016

This paper presents the development of a portable vane rheometer to estimate concrete plastic viscosity and yield stress. The apparatus can be used not only in laboratory but also on construction site. In this study, new blade geometry was proposed to minimize the effect of segregation of concrete during testing, and also to expand the wide range of concrete workability with a slump of approximately from 7 cm to fluid concrete, and concrete with high plastic viscosity such as concrete with mineral additions. The used blade (U shaped and reversed) allows reducing the vibration of the apparatus, and obtaining more stable measurements. The obtained results permit validating the rheometer test procedure and confirmed that the results are reliable, with a low coefficient of variation of 9% for repetitive test and of 5.8% for reproductive tests. © 2016 Vilnius Gediminas Technical University (VGTU) Press

Morand D.,University of Marne-la-Vallee | Perret P.,Artelia | Demilecamps L.,VINCI Construction | Machu A.,IOSIS
Applications of Statistics and Probability in Civil Engineering -Proceedings of the 11th International Conference on Applications of Statistics and Probability in Civil Engineering | Year: 2011

Germa is a French national research project aiming at risk and control in complex civil engineering projects. Our proposal aims to carry on the performances improving the engineering field by better managing complex projects in civil engineering. The methodology of the project will integrate risks related to this complexity of projects. The approach considers the incidence of the risk management on the functional level of the relations between owners, project managers, designers and contractors. The present research aims to analyse the risk management according to the stage of the project, the type of impact and the concerned stakeholder. We have presented the result with a three-dimensional matrix. This research was undertaken by a multi-field team (universities, project managers and designers, civil engineering companies) and it has been funded by French National Research Agency and by the cluster Advancity. © 2011 Taylor & Francis Group, London.

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