Characteristics of energy dissipation and strain field evolution in rubber soil-cement composites under cyclic loading and unloading

To investigate the effect of rubber particle on the energy dissipation characteristics and damage evolution of cement soil (CS) under cyclic loading, graded cyclic loading-unloading tests were conducted on rubberized cement soil (RCS). By integrating digital image correlation (DIC) technology, the effects of rubber content and particle size on the stress-strain behavior, energy density, damage variable (D), damping ratio, and strain field of CS were analyzed. Results indicated that as the cycles number increased, the stress-strain curve of the RCS specimen exhibited a transition from sparse to dense characteristics. In the ranges of 20%, 40%, and 60% stress amplitude, both the input energy (U_I) and dissipated energy (U_D) displayed a two-stage attenuation characteristic, characterized by an initial steep decrease followed by a progressive decline as the cycles number increased. Conversely, at an 80% stress amplitude, the evolution of energy demonstrates a slow attenuation pattern. The incorporation of rubber particles effectively dissipated a portion of the energy through elastic deformation. This mechanism mitigates structural damage during cyclic loading-unloading, resulting in a reduction of D by 27% to 45% when compared to the CS specimen. The damping ratio increased with rubber content, while specimen with 0.1 mm rubber particles demonstrated superior damping performance at a given dosage. An increase in rubber content was accompanied by a transition in the failure mode of specimen from brittle to ductile, characterized by multiple cracks, and a significant enhancement in transverse deformation ability.