Recently, Prof. Guohao Fang from the Institute for Advanced Study (IAS) at Shenzhen University published a research paper titled "Microstructure and micromechanical properties of interfacial transition zone in green recycled aggregate concrete" in the Journal of Building Engineering, a journal in the field of structure and construction technology with an impact factor of 7.144 in the JCR Q1 category in 2022. The paper studied the microstructure and micromechanical evolution of the interfacial transition zone (ITZ) of green recycled aggregate concrete synthesized from construction and industrial waste. The work was completed in collaboration between Shenzhen University and Shenzhen Institute of Information Technology. Shenzhen University was the first completing unit, with Prof. Guohao Fang (Shenzhen University) as the first author of the paper and Prof. Bing Liu (Shenzhen Institute of Information Technology) as the corresponding author.

In recent years, the dismantling of building structures has led to the discharge of a large amount of construction waste, causing serious environmental pollution and depletion of landfill space. This is not conducive to the green development of the ecological environment. How to scale and high-value utilization of construction waste has become an increasingly concerned issue. Using construction demolition waste and industrial waste as raw materials to prepare green recycled aggregate concrete is considered a new type of sustainable concrete. The concrete uses crushed, cleaned, and graded recycled aggregate made from construction demolition waste, mixed with a certain proportion of graded aggregate to solve the problem of a large amount of construction waste disposal and the resulting environmental problems. In addition, using industrial waste (such as fly ash and slag) to prepare alkali-activated cementitious materials also helps to recycle industrial waste resources and reduce carbon dioxide emissions. The microscopic characteristics of the interface between recycled aggregate and cementitious materials are one of the key factors affecting the macroscopic performance of green recycled aggregate concrete. This study used microscopic structural and mechanical characterization methods to systematically analyze the micro-evolutionary mechanism of ITZ. The research shows that the ITZ between recycled aggregate and alkali-activated cementitious materials has a dense microstructure and good bonding performance, which helps to improve the mechanical properties of green recycled aggregate concrete.

Figure 1. Microstructure characterization and performance evaluation of ITZ in green recycled aggregate concrete

This research was supported by the National Natural Science Foundation of China.

Link: https://www.sciencedirect.com/science/article/pii/S2352710223000396