摘要: With the continuous increase of mining amount and the acceleration of green mine construction in China，cemented paste backfill technology has shown a broad application prospect. However，there have been few studies on the mechanical behavior of paste filling materials at different moisture conditions. In order to study the effects of different water content on the uniaxial compression mechanical behaviour of paste backfill materials with low cement content，cemented paste backfill specimens with 3% and 5% cement contents were prepared with tailings，cement and water. The RPH-80 controllable constant temperature-humidity chamber was used to change the specimens moisture content to 0，13%，25% and 36%，respectively. Then the TAW-200 multi-functional mechanical testing machine was used to conduct the uniaxial compression test at a constant displacement rate. The results showed that with the increase of the moisture content，the strength of the backfill decreased. The rate of the decrement in strength gradually accelerated and the relationship between the two parameters could be described quantitatively using a quadratic polynomial fit. The decreasing trend and velocity of the uniaxial compressive strength of the two samples with different cement content were similar. And the compressive strength of cemented paste backfill with 5% cement content was always higher than that of backfill with 3% cement content under different moisture content. On the other hand，with the increase of the moisture content，the elastic modulus of the specimen decreased，the peak strain point first increased and then decreased. The nonlinearity index for the cemented paste backfill was proposed to evaluate the stress-strain curve of cemented paste backfill under different water content. The cemented paste backfill with two different cement content both showed a high nonlinearity at the moisture content of 25%. The nonlinear characteristics of cemented paste backfill could be helpful for the early warning and early intervention of backfill failure. This study provided a reference for further understanding the uniaxial compression mechanical behavior of cemented paste backfill and the safety of backfilling areas.