College of Civil Engineering, Taiyuan University of Technology

【目的】研究晶态和非晶态两种纳米二氧化硅和煤系偏高岭土(CMK)对氧化石墨烯(GO)在水泥净浆中的分散效果及其对水泥净浆性能的影响。【方法】使用紫外分光光度计(UV-vis)探究超声时间以及不同用量ANS和CNS对于GO在饱和氢氧化钙溶液中分散的影响。使用抗压强度结果表征不同颗粒材料对GO分散的影响。通过热重(TG)观测水化产物各物相的脱水、分解过程,并使用压汞法(MIP)分析掺加不同颗粒材料和GO对水泥净浆孔结构的影响。【结果】研究结果表明:非晶态纳米二氧化硅(ANS)、晶态纳米二氧化硅(CNS)的掺量分别为水泥质量的2%、1.5%时,对GO在饱和Ca(OH)2溶液中分散的改善效果最好,同时对水泥净浆力学性能提高效果更好;当CMK掺量为水泥质量的4%时,CMK对GO在水泥净浆中的分散改善效果最好,对水泥净浆力学性能的提高最大;龄期为28d时,复掺4%CMK和0.03%GO对水泥净浆抗折、抗压强度较参考样品分别提高了26.93%和30.41%。热重(TG)和压汞法(MIP)试验结果显示,CMK的二次水化不仅有效改善水泥净浆的孔结构并可以提高GO分散以及水化产物与GO之间的结合力,这是它能够有效提高水泥净浆力学性能的主要原因。

【Purposes】 For improving the mechanical properties of GO incorporated cement paste, two types of nano-silica (crystalline and amorphous) and coal-bearing metakaolin (CMK) were used seprately to improve GO dispersion in cement paste. 【Methods】 UV-vis spectropho- tometry was used to investigate the effects of ultrasound time and different dosages of amorphous nano-silica (ANS) and crystalline nano-silica (CNS) on the dispersion of GO in saturated calcium hydroxide solution. The effects of different particle materials on GO dispersion were character- ized by using compressive strength results. The dehydration and decomposition processes of vari- ous phases of hydration products were observed by thermogravimetric (TG) analysis, and the effect of adding different particle materials and GO on the pore structure of cement paste was ana- lyzed by mercury intrusion porosimetry (MIP). 【Findings】 According to UV-vis spectroscopic study, when the contents of ANS and CNS were 2% and 1.5% by weight of cement, respective- ly, GO dispersion in saturated Ca(OH) solution is improved greatly. Compared with two nano- silicas, CMK is more effective to improve the compressive strength of GO incorporated cement paste. At the age of d, the flexural strength and compressive strength of the cement paste in- corporated with 4% CMK and 0.03% GO are 26.93% and 30.41%, respectively, higher than those of a plain cement paste sample. The results of TG and MIP tests showed that the pozzola- nic reaction of CMK can effectively refine the pore structure of cement paste, improve GO disper- sion, and enhance the bonding between hydration products and GO, which is the main reason why CMK can effectively improve the mechanical properties of GO incorporated cement paste.

国家自然科学基金面上项目(52178238);广东省海洋土木工程耐久性重点实验室开放基金;江苏省土木工程材料重点实验室开放课题基金

刘卓鹏,王雅楠,陈雅,等.不同颗粒材料和氧化石墨烯对水泥净浆性能的影响[J].太原理工大学学报,2024,55(5):881-891.

LIU Zhuopeng,WANG Ya’nan,CHEN Ya,et al.Effect of different particulate materials and graphene oxide on properties of cement paste[J].Journal of Taiyuan University of Technology,2024,55(5):881-891.