Bitumen emulsion rheology and stability under different pH conditions
people on the asphalt pavement quality, safety and comfort have become increasingly demanding, in order to respond to these changes, the road builders are looking for more cost-effective pavement maintenance and programming. Surface treatment technology has become one of the asphalt or concrete pavement preventive maintenance in the most cost-effective, by spraying asphalt binder in the old road surface, and then a layer of compacted aggregate, spraying it into compacted asphalt binder to road surface coating. Improved by the surface treatment layer macrotexture existing pavement, and provides good anti-slip high friction surface, and improve traffic safety. Bitumen emulsion as a cleaning material, can greatly reduce power consumption. However, the relatively weak mechanical properties, and the interaction between the various components inside unclear. Since bitumen emulsion in road maintenance and construction in the blind use of its applications are typically limited to non-structural layer. Bitumen emulsion consisting of bitumen, water and an emulsifier (usually surfactants) composition. Generally, considered a standard bitumen emulsion O / W type, except for some minor component mainly comprising 40-75% bitumen, 25-60% water and 0.1-2.5% of surfactant (by weight) . It determines the nature of the surfactant on the surface charge properties of asphalt cement (AC) (Fig. 1). 
emulsion stability in the spray application of the bitumen emulsion and mixing vital stability of certain formulations of the bitumen emulsion depends on factors, e.g., hydrophilic – lipophilic deviation (HLD) and a surfactant affinity difference (SAD ). HLD measure is a measure of surfactant distribution between the bitumen and water phases bitumen emulsion. FIG. Fig. 1 (bc), the asphalt emulsion used in the preparation of an alkyl amine (-NH2), there are two types of O / W emulsion, i.e. the emulsifier migrates to the asphalt phase with / without surfactant assigned the case. However, alkylamine solution (-NH2) and an alkyl ammonium (-NH3) a significant degree of influence from a bitumen emulsion by pH. Typically, using an acid solution (e.g. hydrochloric acid and phosphoric occasionally) to adjust the pH of cationic asphalt emulsion, in order to regulate the stability of the bitumen emulsion. In addition, the rheological behavior of asphalt is asphalt accurate description of civil engineering – sensitive emulsion mixture performance specifications. Recently, Michigan Technological University (Michigan Technological University) , especially accountingProfessor level TF by the interaction of the asphalt bitumen emulsion with water in different levels of acidic and basic research, and found that the acidic and basic bitumen emulsion significantly affect its stability level, and acidic environment is conducive to water cationic asphalt emulsion remains stable. Apparent viscosity bitumen emulsion with the increase of shear rate decreases, the rheological behavior of bitumen emulsion mixed with acid and base solution is similar to non-Newtonian fluid, the shear until a certain threshold value. For each temperature, different shear reached the threshold, and there are non-Newtonian behavior of the Newton into linear trend, and this threshold is inversely proportional to temperature, as the temperature increases, the shear rate threshold value becomes smaller. Acidic and basic levels have important implications for the bitumen emulsion and the chemical bonds of the residue, a functional group content changes significantly affect the stability and rheology of the bitumen emulsion and the residue. The study was published in Journal of Cleaner Production (2019,235,583-589, SCI a district, Top, IF = 6.395), the corresponding author is Professor You Zhanping , the first of which is doctoral You Lingyun . 
Author: You Zhanping in 2003, graduated from the American University of Illinois at Urbana-Champaign (UIUC), doctorate in civil engineering, the current US Michigan Technological University life Professor, distinguished Professor, the United States registered professional civil engineer (professional Engineer). Professor Ren Changan University School of highway since October 2010, doctoral tutor, Shaanxi Province, \”Shaanxi Scholar\” distinguished professor. Selected in 2014 the Ministry of Education, \”Cheung Kong Scholars Program\” employed \”Cheung Kong Scholar\” lecture as professor of Chang\’an University. As US NSF National Science Foundation, Science and Technology Association, NCHRP project evaluation experts, evaluation experts in several countries as Canada, Switzerland, China and other Science Foundation project, as evaluation experts, more than 30 journals, as a member of ASCE PavementChairman and Chairman of the Committee on asphalt and other materials. Research microstructure comprising asphalt mixture, micromechanics, bituminous material characterization and testing methods, asphalt pavement design method, new environmentally friendly bituminous material. Published more than 400, of which 200 were included SCI, more than 7,000 citations, co-edited eight conference proceedings, technical reports 20, 180 academic reports at professional meetings. Thesis research group http://www.cee.mtu.edu/you/Publications.html link https://www.sciencedirect.com/science/article/pii/S0959652620304649?via%3Dihub
