Evaluation of Microcrack Size in Rubber Concrete ITZ Exposed to Sulfate Attack

Abstract

The width of microcracks of the interfacial transition zone (ITZ) in rubber concrete exposed to sulfate attacks was investigated. The ITZ affects the mechanical properties of concrete to a certain extent. Therefore, the study of ITZ microstructure can provide a theoretical basis for the mechanical properties of rubber concrete. Specimens with 0%, 10%, and 20% replacement by volume of fine aggregates with rubber were exposed to 5% sodium sulfate solution. The effects of rubber particle size (i.e., 5–10, 10–20, 30–50, and 50–90 meshes) on microcrack width were considered. Ordinary concrete without rubber was added as a control. The microcrack width of the ITZ in composites was observed in the test, in which approximately 27 scanning electron microscopy images were obtained from each mixture. With the same rubber particle size, the ITZ microcrack width of concrete with 20% rubber was larger than that of concrete with 10% rubber content. With the same rubber content, the microcrack width increased as rubber particle size increased.