Mechanical responses of freeze-thaw treated natural stone masonry subject to compressive variable amplitude fatigue loading: Insights from stiffness loss and constitutive characterization

Stiffness loss and catastrophic failure frequently occur in natural stone masonry subject to freeze-thaw action and cyclic stress, which may incur serious engineering disasters and casualties. This work strives to experimentally unveil the mechanical responses of a medium-grained building sandstone exposed to dual effects of freeze-thaw and cyclic stress. Testing results are presented from the insights of volumetric deformation, secant modulus evolution. A drop in secant modulus of the first cycle is observed in the failure cyclic loading stage, whereas all former stages exhibit a modulus increase. This precursor well applies to all samples which is freeze-thaw and stress level independent. The development of Poisson's ratio as well as stress level at onset of volume reversal are also presented. A theoretical modelling is put forward to characterize the axial and circumferential strains exposed to variable cyclic stress. The model shows decent effectiveness calibrated by testing results, the way to determine constants in models is introduced in detail, which can be used by readers in a broader range of construction materials.

Automated summary

This study experimentally examines the mechanical responses of a medium-grained building sandstone exposed to freeze-thaw and cyclic stress. The results show a drop in secant modulus during the failure cyclic loading stage, while all previous stages exhibit modulus increase. A theoretical model is proposed to characterize the strains exposed to variable cyclic stress.