Bentonite slurry is a type of excavation fluid widely used in civil engineering and construction projects. Based on its application, as highlighted in the reference, it serves a crucial role in stabilizing excavations during construction processes.
Understanding Bentonite Slurry
Essentially, bentonite slurry is a mixture primarily consisting of bentonite clay and water. When bentonite clay is mixed with water, it forms a viscous suspension or slurry. This mixture possesses thixotropic properties, meaning it becomes less viscous when stirred but thickens when left standing. These properties make it ideal for supporting trench walls and preventing collapse during excavation work.
Key Application in Construction
One significant application of bentonite slurry mentioned in the reference is in the construction of concrete diaphragm walls. These are structural elements often used in deep foundations, cut-off walls, or retaining walls.
During the excavation of the trench for a diaphragm wall, bentonite slurry is pumped in. It exerts hydrostatic pressure against the trench walls, counteracting the earth pressure and preventing the soil from caving in. The thixotropic nature allows it to remain fluid enough to pump but thickens quickly to support the walls when excavation pauses.
Why Bentonite Slurry is Preferred
The reference explicitly states that bentonite slurry is considered one of the most foolproof excavation fluids in building concrete diaphragm walls. A key reason for this reliability is its versatility: it can be used in all forms of soil.
This universal applicability provides a significant advantage over other types of excavation fluids, such as polymer slurry. The reference notes a limitation for polymer slurry, requiring that the sand content in the total soil should be just 2% for its effective use. Bentonite slurry does not have such a restrictive soil composition requirement, making it a robust choice across diverse geological conditions.
In summary, bentonite slurry is a vital excavation fluid, particularly valued for its reliable performance in supporting trench walls during the construction of concrete diaphragm walls, irrespective of soil type.
