振动拌和对混凝土强度及其抗冻性能的影响

为研究混凝土振动拌和过程中的振动参数对混凝土强度和抗冻性能的影响,通过正交试验分析了振动功率、振动时间、拌和次数对混凝土抗压强度的影响,得到了实验室条件下混凝土振动拌和的最优参数组合;在此基础上,对以该最优振动参数振动拌和的混凝土试件进行冻融试验,分析了振动拌和对混凝土抗冻性能的影响.试验结果表明,振动功率对混凝土试件的抗压强度影响较为显著,而振动时间对其影响较小;振动拌和可有效提高混凝土的抗压强度,以本试验获得的最佳振动参数振动拌和的混凝土,其28d抗压强度较相同配比的静力搅拌的普通混凝土抗压强度提高24.31%;随冻融循环次数的增加,经振动拌和的混凝土试件的质量损失率和抗压强度损失率均明显低于采用静力搅拌的混凝土的相应指标,振动拌和有助于提高混凝土的抗压强度和抗冻性.

Strength and Frost-Resistance Properties of the Vibration-Mixed Concrete

The influence of vibration parameters on strength and frost-resistance properties of vibration-mixed concrete was experimentally studied. Firstly, the effects of vibration power, vibration time and mixing numbers were analyzed through orthogonal tests to determine the optimal vibration parameters; then, freeze-thaw tests were conducted on those concrete specimens prepared according to the optimized vibration parameters to analyze the frost-resistance properties. Results show that the vibration power has a more significant effect on the compressive strength of concrete than the mixing numbers and the vibration time. Through vibration-mixing, the 28d compressive strength increase by 24.31% compared with those prepared by static-mixing method. With the increase of freeze-thaw cycles, the mass loss rate and compressive strength loss rate of the vibration-mixed concrete are significantly lower than those of the static-mixed concrete. The concrete compressive strength and the frost-resistance properties can be improved through the vibration-mixing process.