Casing Slime Treatment Control Study with Electrical Resistivity

In the cast-in-place concrete expanded bottom pile method with large diameters, slime and impurity accumulation during ground excavation can impact the pile tip shape and tip bearing capacity. Real-time assessment of slime treatment at the bottom of the hole is challenging. This study aims to evaluate the effectiveness of electrical resistivity control and sand fraction control in treating slime at the bottom of the borehole. On-site construction experiments were conducted using a special pump and a venturi plant. The resistivity and sand fraction were monitored and controlled during slime treatment. Results showed that the special pump effectively treated slime, while the resistivity remained relatively constant. The sand fraction decreased significantly, meeting the required level for concrete quality. The relationship between sand fraction and electrical resistivity was analyzed. The study concludes that while the slime treatment method was effective, the electrical resistivity measurement method requires further refinement to observe the decrease in sand fraction resulting from slime treatment.