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,1000目(5.25μm)石粉的掺入使屈服应力较掺400目(17.34μm)石粉降低了48.4%,但较掺600目(11.23μm)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C 3S溶解和C-S-H生成,加快水泥水化进程。
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 1000 mesh(5.25μm)stone powder reduces the yield stress by 48.4%compared with that of 400 mesh(17.34μm)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(11.23μm)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 C 3S and the generation of C-S-H,which can accelerate the hydration process of cement.
作者
邓国庆
屠林春
赵文昊
李炜
DENG Guoqing;TU Linchun;ZHAO Wenhao;LI Wei(The Fourth Engineering Co.,Ltd.,Second Harbor Engineering Co.,Ltd.,Wuhu 241000,China;Jiangsu Sobute New Materials Co.,Ltd.,Nanjing 211103,China)
出处
《硅酸盐通报》
CAS
北大核心
2023年第11期3807-3815,共9页
Bulletin of the Chinese Ceramic Society
基金
中交二航局石灰石粉研究课题(JSFW-20230602-005202)。
关键词
石灰石粉
水泥浆体
流变性能
屈服应力
水化机理
limestone powder
cement paste
rheological property
yield stress
hydration mechanism
