Formulation studies of the SCORE Project
- Highways Magazine No. 158 - March / April 2008
Bernard ECKMANN
Technical Management EUROVIA (France)
Frédéric DELFOSSE
Research Center EUROVIA (France)
José Luis Peña
FENIX Project Technical Coordinator
Responsible Probisa Technical Assistance during the project (Spain)
Jean WALTER,
Ian Michaël LANCASTER
NYNAS (UK)
José Miguel Baena
Government Department of Works and Public Spaces. Ayto. Of Madrid.
Head of the Technology and Roadway Studies of CEDEX during the project (Spain)
Lionel HATE
Claire NAUDAT
CETE Ouest, Laboratoire des Ponts et Chaussées Regional St-Brieuc (France)
Yves BROSSEAUD
Alain BEGHIN
Frédéric placin
Laboratoire des Ponts et Chaussées Regional Nantes (France)
ABSTRACT
The SCORE project has among its main objectives, evaluation and comparison of the foam bitumen and bituminous emulsions in the cold recycling of bituminous materials. In the latter case, has been paid special attention to submicron bituminous emulsions (referred later "nanoemulsions"), ie, emulsions characterized by a narrow particle size distribution and a mean diameter submicron. Another aim of the SCORE project was the verification of the ability of discrimination of various laboratory tests that can be used.
The studies were mainly conducted with two types of milled material (RAP) from a work in Spain (RAP 1) and another in France (RAP 2). formulation parameters as the origin, the content and degree of bitumen and the addition of cement and / or rejuvenating oil were studied.
Although the data are insufficient to support fully definitive conclusions, the work shows the interest of the test methods used by SCORE within the framework of a methodology for formulation of mixtures recycled: rotary press, test torque, immersion-compression, stiffness changing with time.
Similarly, treatment with foam bitumen appears to be less sensitive to the characteristics of milling and formulation variables treatments emulsion or nanoemulsion. In all techniques conserved resistance improved with the addition of cement (or lime). The order of magnitude of this improvement can be, however, variable and must be verified according to the type of milling, bitumen and technique. In certain particular cases (bitumen 70 / 100 paraffinic), the use of nanoemulsion has improved significantly the mechanical properties of the final mixture (stiffness, compressive strength).
For treatments emulsion must strike a balance between the particle size of the emulsion and the content of residual surfactant, depending on the nature of the milling and bitumen used. From this viewpoint, the manufacturing technique nanoemulsions, for their ability to control these parameters is particularly promising.
KEYWORDS:
Emulsion, nanoemulsion, Foam bitumen, Formulation, Milling, SCORE Project Mix
Bituminous cold.