Curing Stress Influences the Mechanical Characteristics of Cemented Paste Backfill and Its Damage Constitutive Model

As mechanical characteristics are one of the most important indexes that represent the backfill effect of CPB, curing stress is less considered, thus, establishing a damage constitutive model under the effect of curing stress has great significance for the stability of CPB. Firstly, a multifield coupling curing experiment was developed, and a uniaxial pressure testing experiment was used to test the mechanical parameters. Then, the evolution rule of mechanical characteristics of CPB, considering the effect of curing stress, was analyzed. Secondly, combined with elastic mechanics and damage mechanics theory, a damage constitutive model of CPB was explored. Thirdly, based on the laboratory results, an established damage constitutive model was verified. The results indicate that uniaxial compressive strength (UCS) of the CPB was significantly improved because of increasing curing stress and was also influenced by curing age. It was also shown that there existed four stages for the stress-strain curve of the CPB specimens. Moreover, the stress-strain curves of the model and the experiment’s results were the same. There were also good validity and rationality for the established two-stage damage constitutive model, which can provide a good reference for engineering applications of CPB.

This creative work has been published under the Creative Commons Attribution 4.0 International (CC-BY 4.0) license which allows copying, and redistribution as well as adaptation of the original work provided appropriate credit is given to the original author and the conditions of the license are met.