化学发泡式泡沫水泥浆稠化实验方法对比与分析

Comparison and Analysis of Thickening Experiment Methods for Chemically Foamed Cement Slurry

水泥浆的稠化实验使用稠化仪,但泡沫水泥浆中本身含有气体,在加压过程中会造成稠化性能测量误差。针对此问题,采用3种测试方法测试了不同加量发泡剂条件下,化学发泡式泡沫水泥浆的稠度性能,并优选出最优的测试方法。分析了测试方法误差的产生原因,并通过力学分析和计算对最优测试方法的稠度曲线进行修正。结果表明,发泡剂反应剩余物对泡沫水泥浆具有促凝作用,含发泡剂剩余物的水泥浆稠化时间比不含发泡剂剩余物的少41%,其影响不能忽略;使用不含气体和含有气体的水泥浆所测稠化曲线相差不大(不含有和含有气体的水泥浆稠化时间相差1 min和11 min),但其稠化曲线形态有所差别,含有气体的泡沫水泥浆测得的稠化曲线更接近直角稠化;当气体含量较少或者水泥浆后期稠度增长较快时,修正前后的稠化时间可能相差不大,化学发泡式泡沫水泥浆修正前后达到100 Bc的稠化时间相差3 min。但当泡沫水泥浆密度较小、气体含量较大,或者后期稠度增长较慢时,必须对测得的数据进行修正后才能使用。

Consistency tester is used to measure the thickening of cement slurry. For foamed cement slurries, air contained in the slurries often results in errors in consistencies measured. To minimize the effects of air on the consistency of cement slurry, three methods have been used to measure the consistencies of foamed cement slurries treated with different concentrations of foamers, and an optimized measuring method has been selected. Sources of the errors have been analyzed, and the consistency curves obtained from the optimized measuring method corrected through mechanical analyses and calculation. It was found that the residue foamers in cement slurry accelerated the thickening process, and the thickening time of the cement slurry containing residue foamer was 41% less than that of the cement slurry with no residue foamer, indicating that the effects of residue foamer should not be ignored. In two consistency tests with one cement slurry containing air and another one containing no air in it, the differences in thickening times were small（1 min and 11 min, respectively）, while the shapes of the thickening curves were quite different; the thickening curve of the foamed cement slurry was more of right-angled. Cement slurry containing less air, or cement slurry with later consistency increasing faster, difference between the thickening times before and after correction was small; for chemically foamed cement slurries, this time difference was only 3 min when the consistencies before and after correction had both reached 100 Bc. For cement slurries with low density and high air content, or cement slurry with its later consistency increasing slowly, the consistency measured has to be corrected.