Field Test on the Application of Industrial Solid Waste in the Grouting Process of Pre-Bored Grouted Planted Pile

In the installation of pre-bored grouted planted (PGP) piles and other composite pile foundations, cement is commonly used in the grouting stage. However, the cement-production process generates significant CO2 emissions, which are not favorable for achieving low-carbon societal goals. This study explores the use of industrial solid waste (mineral powder and gypsum powder) mixed with cement as a grouting material in test pile TP1, while traditional cement grout was used in test pile TP2. Both test piles were instrumented with optical fiber sensors along their shafts. The findings indicate that the ultimate load-bearing capacity of TP1 was approximately 93% of that of TP2, signifying a 7% reduction when mineral and gypsum powder were added to cement. Additionally, TP1's peak surface friction in various soil layers ranged from 1.29 to 2.79 times that of the bored pile, whereas TP2's peak surface friction was about 1.42 to 3.10 times higher. The cement consumption for TP1 was roughly 65% less than for TP2, and the cost of grouting materials for TP1 was reduced by 35%. This study confirms that utilizing solid waste in the grouting stage of PGP piles is feasible, and optimizing material proportions may enhance future performance.