Preparation of anti-washout cement-stabilized marine soft clay for scouring protection of wind power pile foundations

This study aims to prepare an anti-washout grout using marine soft clay to stabilize the wind power pile foundations. The cement, hydroxypropyl-methyl cellulose ether (HPMC), and sodium silicate were chosen as the main materials to modify the marine soft clay, and the fluidity, bleeding rate, setting time, rheology, anti-washout characteristics, and compressive strength were investigated. The results showed that high cement content, HPMC, and sodium silicate decreased the workability of grout while enhancing the washout resistance. The addition of HPMC and sodium silicate would increase the yield stress and plastic viscosity of the grout. The sodium silicate content was the key factor influencing the early strength, while the cement content and HPMC affect the later strength. The microstructures including the morphology of C-S-H gels and the content of ettringite and calcium hydroxide significantly changed with the addition of sodium silicate, and Friedel's salt was observed through the microstructure analysis. This study can provide effective guidance for the utilization of marine soft clay, the preparation of anti-washout grout, and the control of pile foundation stability.

Automated summary

This study aims to develop an anti-washout grout using marine soft clay for stabilizing wind power pile foundations. Main materials used for modification were cement, hydroxypropyl-methyl cellulose ether (HPMC), and sodium silicate. The study investigated various properties of the grout, including fluidity, bleeding rate, setting time, rheology, anti-washout characteristics, and compressive strength. The results showed that high cement content, HPMC, and sodium silicate reduced workability but improved washout resistance. The addition of HPMC and sodium silicate increased yield stress and plastic viscosity of the grout. Sodium silicate content influenced early strength, while cement content and HPMC affected later strength. The microstructure analysis revealed significant changes in C-S-H gel morphology and the content of ettringite and calcium hydroxide, along with the presence of Friedel's salt. This study provides valuable guidance for utilizing marine soft clay, preparing anti-washout grout, and controlling pile foundation stability.