Influence of Organic Compounds in Shield Aggregate on Concrete Properties

The aggregate obtained from the separation of shield dregs can be utilized in constructing concrete structures, provided that it meets the relevant requirements after appropriate treatment and testing. To meet the demands of shield construction and ensure a harmless and resource recovery process, various high molecular organic polymers such as foams and flocculants are intentionally added during residual soil generation and treatment, which remain on the aggregate surface through adsorption. Through thorough testing and analysis, it has been determined that the interaction between organic matter and cement primarily involves physical actions without any impact on the strength of concrete in later stages. However, this interaction significantly influences gas content within the concrete, retards hydration rate, and notably affects mixture performance. When utilizing shield aggregate for structural construction purposes, it is recommended to increase sampling frequency. Moreover, it is needed to enhance testing standards and reduce polymer content while refraining from using it in high-grade concrete preparation.