Recycling of Aluminosilicate-Based Solid Wastes through Alkali-Activation: Preparation, Characterization, and Challenges

Recycling aluminosilicate-based solid wastes is imperative to realize the sustainable development of constructions. By using alkali activation technology, aluminosilicate-based solid wastes, such as furnace slag, fly ash, red mud, and most of the bio-ashes, can be turned into alternative binder materials to Portland cement to reduce the carbon...

State-of-the-Art Review of Ground Penetrating Radar (GPR) Applications for Railway Ballast Inspection

In the past 20 years, many studies have been performed on ballast layer inspection and condition evaluation with ground penetrating radar (GPR). GPR is a non-destructive means that can reflect the ballast layer condition (fouling, moisture) by analysing the received signal variation. Even though GPR detection/inspection for ballast layers has...

Analysis of Urban Built Environment Impacts on Outdoor Physical Activities: A Case Study in China

Outdoor physical activities can promote public health and they are largely influenced by the built environment in different urban settings. Understanding the association between outdoor physical activities and the built environment is important for promoting a high quality of life. Existing studies typically focus on one type of outdoor activity...

A two-dimensional ordinary state-based peridynamic model for surface fatigue crack propagation in railheads

Based on ordinary state-based peridynamic theory, a 2D peridynamic model has been established to investigate fatigue crack propagation in railheads. The proposed model is verified in terms of rail deformation under a quasi-static load and the ductile material-related fatigue failure model. Good agreements have been achieved between a finite...

Deterioration of organic coatings on concrete under artificial aging

The deterioration of organic coatings on concrete is closely linked to the efficiency in the protection process of reinforced structures. In the present work, polyurea resin and epoxy resin, which are widely used engineering coatings, were selected to measure and compare the performance under artificial aging. Fourier Transform infrared...

A highly selective and stable ZnO-ZrO₂ solid solution catalyst for CO₂ hydrogenation to methanol

Although methanol synthesis via CO hydrogenation has been industrialized, CO₂ hydrogenation to methanol still confronts great obstacles of low methanol selectivity and poor stability, particularly for supported metal catalysts under industrial conditions. We report a binary metal oxide, ZnO-ZrO₂ solid solution catalyst,...