Research on the development of green foaming fluid and the improvement in the performance of foamed cement

The promotion of green foamed cement in engineering aligns with the double carbon strategy and sustainable development goals. The impacts of different foaming materials, their concentrations, the water–binder ratio, the foam–grout ratio, and the mineral powder on the slurry performance of foamed cement were investigated. Orthogonal and comprehensive tests were conducted to examine these factors. The results demonstrated that surface active agent molecules formed an interfacial film with mechanical strength, significantly enhancing the strength and uniformity of green foam. Although the density of green foamed cement was similar to that of commercial foamed cement, its compressive strength at 28 d was three times higher, reaching 8.07 MPa. Scanning electron microscopy observations revealed that the green foamed cement mainly featured 0–0.2-mm-diameter pores with independent pore spaces and thick pore walls, which could be improved by using surface active agents. Moreover, the production price per cubic meter of green foamed cement was 79.56 RMB lower than that of ordinary cement. In brief, the research indicated that the application prospects for green foamed cement are promising due to its performance and economic benefits.