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To clarify the current situation regarding nano layered silicate-modified asphalt, the latest research progress is reviewed in this study. The raw materials and preparation parameters of layered si...

This article aims to elucidate the long-term water stability of a steel slag asphalt mixture. Both chemical composition and physical morphology of the steel slag were characterized by X-ray diffrac...

The objective of this paper is to investigate the effect and mechanism of three types of fibers—basalt fiber (BF), polyester fiber (PF), and lignin fiber (LF)—on the pavement performances o...

Brick waste is a major part of the solid waste generated by construction and demolition activities around the world, and its disposal consumes land and pollutes the environment. At the same time, cement is the main raw material in cement-based materials. Cement production consumes resources and produces greenhouse gases, so is also not environmentally friendly. In this context, grinding brick waste into recycled brick powder (RBP) and using it instead of cement to produce sustainable construction materials is considered a feasible method. Therefore, based on the existing research, this paper reviews the fresh, mechanical, shrinkage, durability and microstructural properties of cement-based materials when RBP partially replaces Portland cement. The literature shows that RBP is rich in SiO2, Al2O3, Fe2O3 and has pozzolanic activity. The workability, mechanical and durability properties of cement-based materials can be improved to a certain extent by adding an appropriate amount of RBP (5%-15%). It is therefore considered a potential raw material for replacing Portland cement in cement-based materials. The utilization of RBP not only saves a large amount of land occupied by piled brick waste but also reduces the dependence of the concrete industry on Portland cement. It can guarantee the sustainability of construction materials and promote prosperity worldwide.

The anti-aging properties and related mechanism of microwave-activated crumb rubber-modified asphalt (ACRMA) were evaluated in this study. Physical and rheological tests were conducted on ACRMA before and after simulated thermal aging, and several microcosmic tests were performed to analyze the aging mechanism. The stiffness, plasticity, and viscoelasticity of ACRMA were less affected by aging than crumb rubber-modified asphalt (CRMA). After aging, ACRMA exhibited better high-temperature performance and permanent deformation resistance than CRMA. The thermal aging process of ACRMA was analyzed, and the anti-aging mechanism model was established. The anti-aging performance of ACRMA was better than that of CRMA.

Waste crumb rubber (CR) can be used in asphalt pavement construction to develop eco-friendly and sustainable pavements. The objective of this study was to investigate the reaction mechanism, high-temperature properties, thermal stability, and volatiles released by CR-modified asphalt (CRMA) activated using microwaves (i.e., ACRMA). The chemical characteristics determined via Fourier-transform infrared spectroscopy revealed that mainly physical reactions occurred in the CRMA before and after activation; however, the swelling reaction in the ACRMA was more efficient than that in the CRMA. These results were confirmed by gel permeation chromatography and atomic force microscopy. The high-temperature performance of the ACRMA was slightly better than that of the CRMA. Additionally, according to stress creep and recovery test results, the microwave activation reduced the stress sensitivity of the rubber-modified asphalt. Thermogravimetric curves indicated that the microwave activation reduced the decomposition temperature of the rubber-modified asphalt. Moreover, the total amount of released volatiles for the base asphalt was significantly larger than that for rubber-modified asphalts, indicating that the CR suppressed the total amount of released volatile gases from the asphalt during the pyrolysis of asphalt. But the addition of CR can increase the release of some toxic gases in CRMA and increase the toxicological potential of asphalt fumes. However, in the initial pyrolysis of rubber asphalts, microwave treatment can reduce the generation of toxic gases. In the later stages of this process, the introduction of rubber particles before and after activation has little effect on the released volatiles.