The Interfacial Adhesion Performance and Mechanism of a Modified Asphalt–Steel Slag Aggregate

Abstract

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. the asphalt and the aggregate are mainly physical interactions. Using an adhesion test, Podoll [14] proved that the peeling of asphalt occurs at the aggregate interface. Ling [15] carried out an adhesion test with asphalt and stone and analyzed the variations of adhesion with shear rate and temperature tests. Tarrer [16] indicated that when steel slag comes into contact with asphalt, the former has good adhesion characteristics since steel slag is an alkaline aggregate, and asphalt contains acidic groups. By exploring the asphalt-filler adhesion characteristics by infrared spectroscopy, Shin [17] found that asphalt around the filler carries polar functional groups. Xu [18] studied the combustion characteristics of asphalt by combining thermogravimetry with infrared spectroscopy.Other researchers have indicated that the angularity coefficient and fractal dimension of the surface texture of a steel slag aggregate have a linear positive correlation with the phase strength of the asphalt-aggregate interface. The greater the surface roughness of the steel slag a...

Mechanical and Damping Properties of Recycled Aggregate Concrete Modified with Air-Entraining Agent and Polypropylene Fiber

“…While a slight increment was found for the specimen containing PP, the splitting tensile strength of concrete increased by 3.85% (50RAC-P1), 4.42% (50RAC-P2), and 3.27% (50RAC-P3). Similar conclusions have been reported by earlier studies [23,31].…”

“…While a slight increment was found for the specimen containing PP, the splitting tensile strength of concrete increased by 3.85% (50RAC-P1), 4.42% (50RAC-P2), and 3.27% (50RAC-P3). Similar conclusions have been reported by earlier studies [23,31]. Furthermore, the splitting tensile strength of concrete decreases by 1.57% (50RAC-A1), 2.42% (50RAC-A2), and 13.53% (50RAC-A3) as compared to that of the 50RAC samples.…”

“…Studies have suggested that due to its high tensile strain, a fiber polymer, as an additive, can contribute to improving the performance of concrete [3,7,21,22]. Furthermore, the study of the effect of the type and dosage of fiber on the mechanical properties of RAC has shown that concrete reinforced with glass and steel fibers can significantly improve the mechanical performance of RAC when the fiber content is within a reasonable range [23]. Additionally, the air entraining agent (AGA) introduces many bubbles in concrete, and it may increase the damping performance of the concrete to a certain extent.…”

Effects of Steel-Slag Components on Interfacial-Reaction Characteristics of Permeable Steel-Slag–Bitumen Mixture

“…When carbonate or alkaline rock is bonded with bitumen containing sufficient active acidic surface substances, the chemical-adsorption process occurs, and water-insoluble compounds are formed on the contact surface of bitumen and aggregate, so the bitumen layer formed on the surface of aggregate has higher water-damage resistance. Alkaline aggregates have the high adhesion to bitumen containing acidic groups [ 20 , 21 , 22 ].…”

A Dy(iii)–organic framework as a fluorescent probe for highly selective detection of picric acid and treatment activity on human lung cancer cells

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