功率超声对水泥基复合材料流变性能的影响

叶姝君¹，梁浩²，刘圣洁³，宋雷¹，赵之仲^1*，彭庚^4，5

1.山东交通学院交通土建工程学院，山东 济南  250357；2.山东鲁中公路建设有限公司，山东 淄博  255086；

3.北京建筑大学土木与交通工程学院，北京  102616；4.北京市市政工程研究院，北京  100032;

5.北京市政路桥科技发展有限公司，北京  100032

摘要：为提高水泥颗粒的分散均匀性，研究功率超声对水泥基复合材料流变性能的影响，采用P·O 42.5普通硅酸盐水泥，以萘系减水剂FDN-C为减水剂，采用功率超声对水泥浆体进行预分散处理，在不同水灰质量比（0.50、0.55）、超声功率（250、500、750 W）、超声时间（0~4 min）下测试浆体的流动度和泌水率，研究功率超声对水泥浆体流变性能的影响。结果表明：超声时间相同时，水泥浆体的流动度随超声功率的增大而增大，泌水率随超声功率的增大而先减小后增大，超声功率为750 W时，不同水灰质量比的水泥浆体的流动度和泌水率均最大；超声功率相同时，超声作用4 min后2种水灰质量比水泥浆体的流动度均最大，水灰质量比为0.50水泥浆体的泌水率随超声时间的增大而呈减小→增大→减小→增大的变化趋势，超声作用3 min时，水灰质量比为0.55水泥浆体的泌水率继续增大。相比减水剂，功率超声在更短时间内改变水泥浆体的流变性能，超声功率为750 W、超声时间为2 min时和超声功率为500 W、超声时间为4 min时改变水泥浆体的流变性能效果最显著。

关键词：水泥基复合材料；功率超声；流变性；流动度；泌水率；减水剂

Influence of power ultrasound on the rheological properties ofcement-based composite materials

YE Shujun¹, LIANG Hao², LIU Shengjie³, SONG Lei¹, ZHAO Zhizhong1*, PENG Geng4,5

1.School of Civil Engineering, Shandong Jiaotong University, Jinan 250357, China；

2.Shandong Luzhong Highway Construction Co., Ltd., Zibo 255086, China;

3.School of Civil and Transportation Engineering, Beijing University of Civil Engineering and Architecture, Beijing 102616, China;

4.Beijing Municipal Engineering Research Institute, Beijing 100032, China;

5.Beijing Municipal Road and Bridge Technology Development Co., Ltd., Beijing 100032, China

Abstract: To improve the dispersion uniformity of cement particles, the influence of power ultrasonic on the rheological properties of cement-based composite materials is studied. Ordinary Portland cement P·O 42.5 is used, with naphthalene-based water reducer FDN-C as the water reducer. Power ultrasonic is employed for pre-dispersion treatment of cement slurry, and the fluidity and bleeding rate of the slurry are tested under different water-to-cement ratios（0.50, 0.55）, ultrasonic powers（250, 500, 750 W）, and ultrasonic times（0,1,2,3,4 min）to investigate the impact of power ultrasonic on the rheological properties of cement slurry. The results show that with the same ultrasonic time, the fluidity of the cement slurry increases with the increase of ultrasonic power, while the bleeding rate decreases first and then increases with the increase of ultrasonic power. When the ultrasonic power is 750 W, the fluidity and bleeding rate of cement slurry at different water-to-cement ratios are the highest. With the same ultrasonic power, the fluidity of both water-to-cement ratio cement slurries is the highest after 4 min of ultrasonic treatment. The bleeding rate of the 0.50 water-to-cement ratio slurry decreases, increases, then decreases, and increases again with the increase of ultrasonic time, while for the 0.55 water-to-cement ratio slurry, the bleeding rate continues to increase after 3 min of ultrasonic treatment. Compared to the water reducer, power ultrasonic can change the rheological properties of the cement slurry in a shorter time. The most significant effects on altering the rheological properties of the slurry are observed when the ultrasonic power is 750 W and the ultrasonic time is 2 min, and when the ultrasonic power is 500 W and the ultrasonic time is 4 min.

Keywords: cement-based composite material; power ultrasound; rheological property; fluidity; bleeding rate; water reducing agent