Study on Microstructure of Recycled Aggregate Concrete by Scanning Electron Microscopy: A Review

Abstract

Recycled Aggregate Concrete (RAC) is a new type of concrete made by utilizing waste concrete as aggregate after treatment. With the enhancement of environmental awareness and resource conservation, but the microstructural part of recycled aggregate concrete is not as important as the macro performance enhancement aspect by scholars. And Scanning Electron Microscope (SEM) is a powerful tool for microanalysis, which can provide high-resolution images of samples as well as information on surface morphology and microstructure. In this paper, the micro-structure of RAC will be comprehensively analyzed according to the performance characteristics of RAC materials and the relevant analysis technology of SEM. Based on the microscopic technology of SEM, the research progress of the micro-structure of RAC was carried out, and the morphology and distribution characteristics of recycled aggregate particles, pore structure and porosity, the interface combination between recycled aggregate and cement matrix, and the relationship between micro-structure and RAC properties were summarized, which provided theoretical support for the future understanding of the micro-structure of RAC, increased the understanding of the micro-structure of RAC materials, and more systematically understood the application of microscopic analysis methods in RAC.