Classification of impact damage patterns of cement cured soils in Pisha sandstone geopolymer based on critical strain rate.

This study investigates the mechanical properties and damage processes of cement-consolidated soils with Pisha sandstone geopolymer under impact loading using the Hopkinson lever impact test. The mechanical properties of cement-cured soils containing Pisha sandstone geopolymer were examined at various strain rates. The relationship between strain rate and strength of the geopolymer-cemented soil was established. As the strain rate increased, the coefficient of power increase for the Pisha sandstone geopolymer cement-cured soil initially rose before gradually stabilizing. The pore structure of the crushed specimens was analyzed using Mercury intrusion porosimetry. Based on the observed pore changes under impact loading, the pore intervals of the geopolymer-cemented soil were defined. A fitting model linking strain rate and porosity was developed. As strain rate increased, the porosity of the specimens first increased and then decreased, with larger internal pores gradually transforming into smaller ones. The highest porosity was observed at a strain rate of 64.67 s. Crushing characteristics of the cement-cured soils under impact loading were determined through sieving statistics of the crushed particles. The average particle size of the fragments decreased as the strain rate increased. The fractal dimension initially decreased and then increased with the rise in strain rate, reaching its lowest value at a strain rate of 64.67 s. Based on the dynamic mechanical properties, microscopic porosity, and fracture characteristics, the critical strain rate and damage form for cement-consolidated soils with Pisha sandstone geopolymer under impact loading were determined. This study offers valuable insights for the practical application of Pisha sandstone geopolymer cement-cured soils in engineering.