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硅酸盐通报 ›› 2023, Vol. 42 ›› Issue (11): 3807-3815.

所属专题: 水泥混凝土

• 水泥混凝土 • 上一篇    下一篇

磨细石灰石粉-水泥流变性能及水化机理研究

邓国庆1, 屠林春1, 赵文昊2, 李炜2   

  1. 1.中交二航局第四工程有限公司,芜湖 241000;
    2.江苏苏博特新材料股份有限公司,南京 211103
  • 收稿日期:2023-06-21 修订日期:2023-07-11 出版日期:2023-11-15 发布日期:2023-11-22
  • 作者简介:邓国庆(1987—),男,高级工程师。主要从事混凝土建筑相关的研究。E-mail:1245395768@qq.com
  • 基金资助:
    中交二航局石灰石粉研究课题(JSFW-20230602-005202)

Rheological Properties and Hydration Mechanism of Finely Ground Limestone Powder-Cement

DENG Guoqing1, TU Linchun1, ZHAO Wenhao2, LI Wei2   

  1. 1. The Fourth Engineering Co., Ltd., Second Harbor Engineering Co., Ltd., Wuhu 241000, China;
    2. Jiangsu Sobute New Materials Co., Ltd., Nanjing 211103, China
  • Received:2023-06-21 Revised:2023-07-11 Online:2023-11-15 Published:2023-11-22

摘要: 为研究石灰石粉细度和掺量对水泥浆体流变性能和水化进程的影响,采用安东帕流变仪测试了新拌浆体的流变性能,通过计算触变环面积表征浆体的触变性,同时利用湿堆积密度测试和水膜层厚度计算结果解释石灰石粉对水泥浆体流变行为的影响机制,最后通过微量热测试和XRD定量分析阐明石灰石粉对水泥水化进程的影响规律。结果表明,10%(质量分数)掺量下,1 000目(5.25 μm)石粉的掺入使屈服应力较掺400目(17.34 μm)石粉降低了48.4%,但较掺600目(11.23 μm)石粉提高了15.6%;相同细度下,掺10%和20% 600目石粉浆体屈服应力较空白组分别降低76.7%和81.8%;石粉的掺入降低了浆体的触变性,并改变了触变性随时间的变化规律;增加石粉细度和掺量使浆体湿堆积密度增大,颗粒水膜层厚度提高,浆体屈服应力和稠度减小;增大石粉细度能够缩短水化诱导期,使水化第二放热峰前移,促进早期C3S溶解和C-S-H生成,加快水泥水化进程。

关键词: 石灰石粉, 水泥浆体, 流变性能, 屈服应力, 水化机理

Abstract: In order to study the effect of limestone powder fineness and dosage on the rheological properties and hydration process of cement paste, the rheological properties of freshly mixed paste were tested by Anton Paar rheometer, and the thixotropy of paste was characterized by calculating the thixotropic annulus area. Meanwhile, the mechanism of the influence of limestone powder on the rheological behavior of cement paste was explained by using the results of wet stacking density test and the calculation of the thickness of water film powder on the rheological behavior of cement paste was clarified by microcalorimetry test and quantitative analysis. Finally, the influence of limestone powder on the hydration process of cement was clarified by microcalorimetric test and XRD quantitative analysis. The results show that, at 10% dosage, the doping of 1 000 mesh (5.25 μm) stone powder reduces the yield stress by 48.4% compared with that of 400 mesh (17.34 μm) stone powder, but it improves by 15.6% compared with that of 600 mesh stone powder. At the same fineness, the doping of 10% and 20% 600 mesh (11.23 μm) stone powder reduces the yield stress of the paste by 76.7% and 81.8% compared with that of the blank group, respectively. Doping stone powder reduces the thixotropic behavior of paste and changes the variation rule of thixotropy with time. Increasing the fineness and dosage of stone powder increases the wet packing density of paste, and the thickness of water film layer, resulting in a decrease in yield stress and consistency of slurry. Increasing the fineness of stone powder can shorten the hydration induction period, move the second exothermic peak of hydration forward, and promote the early dissolution of C3S and the generation of C-S-H, which can accelerate the hydration process of cement.

Key words: limestone powder, cement paste, rheological property, yield stress, hydration mechanism

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