eng Science and Education Publishing American Journal of Civil Engineering and Architecture 2328-3998 2025-11-17 13 6 123 129 10.12691/ajcea-13-6-1 AJCEA20251361 article Yacouba Konate 1 Layella Ziyani 2 Athanas Konin athanas.konin@inphb.ci 3 Anne Dony 3 ENSAU, Universit¨¦ de Bondoukou, C?te d¡¯Ivoire Institut de Recherche en Constructibilit¨¦, Ecole Sp¨¦ciale des Travaux Publics, France Laboratoire de Sciences G¨¦ographiques G¨¦nie Civil et G¨¦osciences, INP-HB, C?te d¡¯Ivoire The use of cold-mix asphalt is an effective approach to environmental protection. These materials are intended for low- to medium-traffic roads and have significant potential for secondary road networks in African countries. The objective of this article is to study the influence of surfactant use on the bitumen emulsion-aggregate interaction from a microscopic perspective. Two surfactants (designated A and B) and four types of materials (granite, diorite, limestone, and silica) were studied. The tests performed were: emulsion-aggregate compatibility tests, tests to determine the optimal water content of the mixtures, UV-visible adsorption tests by spectrometry, and tests to assess emulsion bond breakdown upon contact with fine minerals. The results show that the surfactant adsorption differed according to the surfactant-substrate pair considered and adsorption tests performed by UV-visible spectrophotometry revealed that surfactant A adsorbed more readily onto the substrates than surfactant B. This could be due to the charge of the respective hydrophilic heads of the surfactants. Adsorption is stronger with surfactant A because its polar charge is greater than that of surfactant B at pH 2. The emulsion ¨C aggregates rupture was all the more rapid as the SiO2 content increased in aggregates. At the rheological level, the behavior of the emulsion-filler mixtures was influenced by the surfactant nature and content, the specific surface area of the aggregates and the emulsion-filler mass ratio. https://pubs.sciepub.com/ajcea/13/6/1/ajcea-13-6-1.pdf bitumen emulsion surfactants adhesion fine minerals UV spectrometry adsorption