Study on volume stability of chemical foaming cement paste

The paper is aimed at investigating the mechanism and cause of volume instability of chemical foaming cement paste. Volume stability were studied by introducing ultimate shear stress of the technical parameter. The research shows that the ultimate shear stress should be between 25 Pa and 40 Pa when the paste was mixed for 30 minutes, and the ultimate shear stress reached 75 Pa when the paste was mixed for 2 hours. The paste is not easy to collapse, sink. By force analyzing of the paste, mathematical model of the paste was established. The ultimate shear stress was controlled by water-binder ratio, quick setting agent and foam stabilizer. The result shows that the water-binder ratio is 0.54∼0.58, the setting accelerator is 2% of cement content, and the foam stabilizer is 1.6% of cement content, which played an important role in the volume stability of the paste.