Mechanical properties and damage model of alkali activated polymer solidified soil containing coal gangue powder

This study investigates the stress-strain relationship and damage evolution mechanism of alkali-activated coal gangue powder-based geopolymer solidified loess under uniaxial compression. Uniaxial compression tests were conducted on specimens with different mix proportions and curing ages, followed by the development of a damage constitutive model based on damage mechanics theory. The experimental results demonstrate that the compressive strength of the solidified loess increases with extended curing periods and higher binder content. By integrating Lemaitre's strain equivalence principle with a composite power function, a damage constitutive model was derived. The model exhibits strong consistency with experimental stress-strain curves, thereby validating its rationality and the accuracy of elastic coefficient determination. These findings provide critical insights into the damage evolution patterns during uniaxial compression failure of alkali-activated coal gangue powder-based geopolymer-modified loess. Furthermore, this study establishes a theoretical framework and offers practical references for characterizing damage constitutive relationships in geopolymer-stabilized soils.