振捣频率对混凝土性能的影响分析

Influence Analysis of Vibration Frequency on Concrete Performance

振捣频率对混凝土性能影响很大,频率不足对提高混凝土强度、密实程度和耐久性作用不大,过振则会出现离析病害。为提高混凝土性能,并保证其处于稳定状态,以济南东岳华庭住宅楼墙体工程为研究对象,采用4种频率对3组不同配合比的混凝土进行振捣,记录各频率下混凝土的出浆及排气时间、气孔大小及分布、强度发展及电通量值。结果表明,选用合适的振捣频率可以有效提高混凝土的性能,对于坍落度为140 mm的C30混凝土,当振捣频率在150 Hz时,混凝土振捣功效、回弹强度、匀质性及抗渗透性均得到较大提升并能处于稳定状态。

The vibration frequency greatly influence the performance of concrete, while the insufficient frequency has little effect on improving the strength, compactness and durability of concrete. Excessive vibration will induceseparation disease. In order to improve the performance of concrete and keep it stable, the wall of Dongyue Huating residential building in Ji’nan is taken as the research object, and three groups of concrete with different mix ratios are vibrated with four frequencies, the time of slurry and evacuation, the size and distribution of air holes, strength development and electric flux of concrete were recorded. The results show that the performance of C30 concrete can be improved effectively by choosing the appropriate vibrating frequency. For C30 concrete with slump of 140 mm, when the vibrating frequency is 150 Hz, the vibration efficiency, rebound strength, homogeneity and anti-permeability of concrete are greatly improved and can be in a stable state.