搅拌速度对新拌混凝土含气量的影响分析

Influence of mixing speed on fresh concrete air content

搅拌速度是混凝土生产过程中的重要工作参数,前期搅拌机工作装置参数优化试验表明,搅拌速度对混凝土含气量的影响较大。普遍认为,随着搅拌速度的增加,含气量呈上升趋势。但当搅拌工艺改变时,此规律将发生变化。因此,要达到对含气量的有效控制,必须研究不同工艺条件下搅拌速度对其的影响规律。就此进行了分析和试验研究,结果表明:采用传统搅拌工艺,新拌混凝土的含气量随着搅拌速度的增加而增加,当搅拌速度超过1.6m/s时含气量会随着搅拌的加快而下降,含气量变化量在1.0%～2.3%之间;采用二次搅拌工艺,含气量随着搅拌速度的增加基本上呈下降趋势,搅拌速度超过1.6m/s时,含气量会随着搅拌的加快而上升,含气量变化量在1.1%～1.75%之间。

Mixing speed is an important working parameter for fresh concrete mixing process.The former test research on parameters optimization of mixer indicated that the effect of mixing speed on fresh concrete air content is rather large.It is well know that the air content will rise as mixing speed increased, while this rule will be changed by means of different mixing technology.For the purpose of effectively controlling air content, the study of the relationship between mixing speed and air content under different mixing technology is necessary.The test results indicate that by means of traditional mixing technology, the air content of fresh concrete will increase as mixing speed increased, then decrease as mixing speed over 1.6m/s,, and the air content excursion is 1.0%-2.3%, while the air content change rule will be opposite under secondary mixing technology, and the air content excursion is 1.1%-1.75%.