橡胶颗粒-钢纤维混掺对碾压混凝土抗冻性及抗冲击性能的影响

In this paper, the frost resistance and impact resistance of roller compacted concrete (RCC) mixed with rubber particles(RP) and steel fiber(SF) were investigated in 25% (by mass) potassium acetate (KAc) as the medium in freezing-thawing cycles. The flexural impact performance, relative dynamic elastic modulus, mass loss, microstructure, and pore structure of RCC were measured. The results show that the accumulated mass loss of RCC increases with the increase of freeze-thaw cycles. The RP have slight effect on the mass loss, the total porosity, the impact property and relative dynamic elastic modulus of RCC. However, the SF can obviously control the rapid growth of the mass loss and improve the flexural impact property. The cumulative mass loss of RCC with 300 freeze-thaw cycles is only 83.94 g/m². The impact number of RCC with 1.3% (by volume) SF raises from 3-5 to 140-170. The initial and final impact number decreases by 70% after RCC specimens being subjected to 300 freeze-thaw cycles. The relative dynamic elastic modulus firstly decreases and then has a slow increase at the later stage. The maximum loss of relative dynamic elastic modulus is 8% when the SF reinforced RCC with 300 freeze-thaw cycles. The loss of relative dynamic elastic modulus of all specimens is less than 10%.