Abstract:The construction of diaphragm wall is greatly affected by bentonite slurry. The quality control of bentonite slurry is the key to ensure the stability of the groove wall during the grooving of diaphragm wall. The quality of bentonite slurry is mainly affected by the type of bentonite, the quality of water used for making slurry, and the mixing amount of bentonite. Based on a diaphragm wall enclosure project in Suzhou, the slurry of the project is studied experimentally. Firstly, the performances of slurry produced by the well water and tap water in the region are compared. Three kinds of bentonites such as sodium earth powder in Fumaying Area of Weifang in Shandong Province, medium powder and high powder in Heishan County in Liaoning Province are selected for the slurry making tests. It is determined that the well water slurrying with 3% bentonite content could not meet the requirements of grooving. Then, five manufacturers of bentonite are selected for the well water slurrying experiments with the different amounts of bentonite. The specific gravity, viscosity parameters, and colloid fraction changes in 8~48 h are measured and recorded after the bentonite slurry is fully hydrated for 24 h with the different amounts. Finally, 7% of Zhejiang Anji super-moist bentonite is determined for slurry construction, which has been effectively used in the current construction of 13 diaphragm walls.
