HAL Id: hal-03207943
https://hal.archives-ouvertes.fr/hal-03207943
Submitted on 26 Apr 2021
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Formulation of cold recycled asphalt mixtures: a microscopic scale study of bitumen emulsion wetting on
virgin aggregates and reclaimed asphalt pavement (RAP)
Yacouba Konaté, Florence Rouyer, Layella Ziyani, Anne Dony, Jean-Eric Poirier, Xavier Chateau, Athanas Konin
To cite this version:
Yacouba Konaté, Florence Rouyer, Layella Ziyani, Anne Dony, Jean-Eric Poirier, et al.. Formulation of cold recycled asphalt mixtures: a microscopic scale study of bitumen emulsion wetting on virgin aggregates and reclaimed asphalt pavement (RAP). 10th International Colloids Conference 2020, Dec 2020, ONLINE, France. �hal-03207943�
Switching of a part of free surfactants from the water- air interface to the water-bitumen interface with the addition of bitumen in the aqueous phase.
Decrease in contact angles with increasing emulsifier content for diorite, because of the high reactivity of this substrate
Contact angles of emulsions with the RAP higher than those of virgin aggregates, whatever the emulsifier nature and content :
Adsorption of free surfactants on aged binder of RAP by their lipophilic part.
Lower emulsion-RAP contact angles when the emulsifier content decreases because of reduction of free surfactants in the medium.
5 - CONCLUSIONS
Formulation of cold recycled asphalt mixtures: a microscopic scale study of bitumen emulsion wetting on virgin aggregates and reclaimed asphalt pavement (RAP)
Yacouba Konatéa,b, Florence Rouyerc, Layella Ziyanib, Anne Donyb, Jean-Eric Poirierd, Xavier Chateauc, Athanas Konina
(a) Institut National Polytechnique Félix HOUPHOUËT BOIGNY, Bd Mamie Adjoua, 1093 Yamoussoukro, Côte d’Ivoire.
(b) Université Paris-Est, Institut de Recherche en Constructibilité, École Spéciale des Travaux Publics, 28 avenue du Président Wilson, 94234 Cachan Cedex, France.
(c) Navier, CNRS, École des Ponts, Université Gustave Eiffel, 14-20 Boulevard Newton Cité Descartes, Champs sur Marne F-774447 Marne-la-Vallée Cedex 2, France.
(d) PQSERENDI, 2 allée de l’Hermine, 78180 Montigny-le-Bretonneux, France
Measurement of surface tensions and contact angles with drop tensiometer Manufacture of substrate model of virgin
aggregate and RAP
Granite block After sawing
After polishing
Virgin aggregate RAP substrate
After coating with aged binder
Polisher
The cold mix asphalt technique is considered to be less energy-consuming and more environmentally friendly. Combined with recycling of Reclaimed Asphalt Pavement (RAP), it saves non-renewable resources. With a view to guaranteeing constructability, the coupling of both techniques requires the determination of the formulation conditions on the basis of knowledge of the interface phenomena between the different constituents of the cold recycled mixture : virgin aggregate and RAP.
1 - CONTEXT
Aged
bituminous binder on surface
RAP
Aqueous phase Bitumen droplets
+ +
BITUMEN
+
+ +
+ + + + + + + +
Surfactants
Heterogeneous mineralogical composition
giving polarity on surface
VIRGIN AGGREGATE
Scientific issues
concerning cold
recycled mixture
Bitumen emulsion
? ?
+
4 - RESULTS
100 2030 4050 6070
Granite Diorite Granite RAP
Diorite
Surface energy (mJ/m²) RAP
Substrate nature
δs Polar δs Dispersive
30 40 50 60 70
0 50 100 150 200 250 300
Contact angle (°)
Time (s) DIORITE
0,9 % A 1,2 % A 1,5 % A
50 60 70 80 90
0 50 100 150 200 250 300
Contact angle (°)
Time (s) RAP
0,9 % A 1,2 % A 1,5 % A 30
40 50 60 70
0 50 100 150 200 250 300
Contact angle (°)
Time (s) GRANITE
0,9 % A 1,2 % A 1,5 % A
Determination of substrate surface energies by linear regression from the Owens-Wendt-Rabel and Kaelble model [Ma, Fu et Wang, 2014]
Substrate Syringe
needle Air
Liquid
𝜸𝑳
𝜸𝑺 θ𝜸𝑺𝑳
+
Emulsion designation
Emulsifier nature
Emulsifier content
Bitumen content
0.9 % A A 0.9 % 65 %
1.2 % A A 1,2 % 65 %
1.5 % A A 1.5 % 65 %
0.9 % B B 0.9 % 65 %
1.2 % B B 1.2 % 65 %
1.5 % B B 1.5 % 65 %
Aqueous phase Bitumen
Colloid mill
Emulsification parameters Aqueous phase : 50°C
Bitumen : 140°C
Colloid mill air gap : 0.5 mm Shear speed : 8,932 rpm Polyamine surfactants : CMC (A) : 0.6 g/l - CMC (B) : 0.2 g/l
3 - METHODOLOGY AND APPROACH
Emulsions formulation by varying surfactant nature and content (70/100 penetration grade bitumen )
Average contact angle of emulsions with substrates after stabilization
3032 3436 3840 4244 4648
Surface tension (mN/m)
Emulsion
Aqueous phase Emulsion
20 30 40 50 60 70 80 90
0.9% 1.2% 1.5%
Contact angle (°)
Emulsifier A content Granite Diorite RAP
20 30 40 50 60 70 80 90
0.9% 1.2% 1.5%
Contact angle (°)
Emulsifier B content
Granite Diorite RAP
30 40 50 60 70
0 50 100 150 200 250 300
Contact angle (°)
Time (s) GRANITE
0,9 % B 1,2 % B 1,5 % B 30
40 50 60 70
0 50 100 150 200 250 300
Contac angle (°)
Time (s) DIORITE
0,9 % B 1,2 % B 1,5 % B
50 60 70 80 90
0 50 100 150 200 250 300
Contact angle (°)
Time (s) RAP
0,9 % B 1,5 % B
Contact angles of emulsion / substrate systems as a function of time, emulsion formulation parameters and the petrographic
nature of the model substrate Increase in the surface
tension of emulsions
formulated, comparatively to those of aqueous phases
Surface energy of virgin aggregate and RAP
+
Electrostatic repulsion
BITUMEN
+
+ + +
+
Bitumen +
droplets in
emulsion RAP
+ + + +
+
Aged binder
+
+
+
Adsorption of free surfactants
2 - RESEARCH OBJECTIVE
Study of physico-chemical phenomena between bitumen emulsion/virgin aggregate and bitumen emulsion/RAP interfaces to apprehend wetting process of emulsion on surfaces of both aggregates types. Determination of cold recycled asphalt mixes formulation in order to ensure durability.
Source
Dosing cell
Camera
Teclis Drop tensiometer
Support (𝟏 + 𝐜𝐨𝐬 𝜽) 𝟐
𝜸𝑳 𝜸𝑳𝑫
= 𝜸𝑺𝑷 𝜸𝑳𝑷
𝜸𝑳𝑫 + 𝜸𝑺𝑫
