Liu Wenhuan, Li Hui, Zhu Huimei, Xu Pinjing
College of Materials Science and Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Materials (Basel). 2020 Mar 6;13(5):1180. doi: 10.3390/ma13051180.
The interfacial adhesion between asphalt and steel slag aggregate is a decisive factor in the formation of an asphalt-steel slag mixture and significantly affects the quality stability of steel slag-asphalt mixtures. In this study, the adhesion between an asphalt and steel slag aggregate, the interfacial microstructure, the adsorption and desorption characteristics, and chemical reactions were, respectively, explored by a PosiTestAT-A adhesion puller, a scanning electron microscope, a net adsorption test, an infrared spectrometer, and a dynamic shear rheometer. The mechanism of adhesion between the asphalt and steel slag aggregate was analyzed from the perspectives of physical adsorption and chemical reactions. The results showed that different factors had different effects on the adhesion of asphalt-steel slag aggregate interface. The freeze-thaw cycle and steel slag aggregate particle size had significant effects on interfacial adhesion, while the asphalt heating temperature, water bath time, and stirring time had relatively weak effects on interfacial adhesion. Compared to a limestone aggregate, the steel slag-asphalt mixture had greater adhesion and better adhesion performance because the pits and textures on the surface of the steel slag aggregate produced a skeleton-like effect that strengthened the phase strength of the asphalt-slag aggregate interface, thereby improving the adhesion and increasing the physical adsorption between the asphalt and steel slag aggregate. In addition, due to the N-H stretching vibrations of the amines and amides, as well as SiO-H stretching vibrations, a chemical reaction occurred between the asphalt and steel slag aggregate, thus improving the adhesion performance between the asphalt and steel slag. Based on the shape of the adsorption isotherm, it was determined that the adsorption type was multi-molecular layer adsorption, indicating that the adhesion between the asphalt and steel slag mainly involved physical adsorption.
沥青与钢渣集料之间的界面粘结力是形成沥青 - 钢渣混合料的决定性因素，对钢渣 - 沥青混合料的质量稳定性有显著影响。本研究分别采用PosiTestAT - A粘结力拉拔仪、扫描电子显微镜、净吸附试验、红外光谱仪和动态剪切流变仪，对沥青与钢渣集料之间的粘结力、界面微观结构、吸附和解吸特性以及化学反应进行了探究。从物理吸附和化学反应的角度分析了沥青与钢渣集料之间的粘结机理。结果表明，不同因素对沥青 - 钢渣集料界面粘结力的影响不同。冻融循环和钢渣集料粒径对界面粘结力有显著影响，而沥青加热温度、水浴时间和搅拌时间对界面粘结力的影响相对较弱。与石灰岩集料相比，钢渣 - 沥青混合料具有更大的粘结力和更好的粘结性能，因为钢渣集料表面的坑洼和纹理产生了骨架状效应，增强了沥青 - 矿渣集料界面的相强度，从而提高了粘结力，增加了沥青与钢渣集料之间的物理吸附。此外，由于胺类和酰胺类的N - H伸缩振动以及SiO - H伸缩振动，沥青与钢渣集料之间发生了化学反应，从而提高了沥青与钢渣之间的粘结性能。根据吸附等温线的形状，确定吸附类型为多分子层吸附，表明沥青与钢渣之间的粘结主要涉及物理吸附。
