Mechanical Properties and Hydration Mechanism of Chemically Activated High Content Fly Ash Composite Cementitious Materials

doi:10.16552/j.cnki.issn1001-1625.2024.1007

Abstract

Abstract: In this study, a high content fly ash (m(slag powder)∶m(fly ash)=1∶3 (mass ratio)) was used as matrix, and the composite activators under different compounding methods were obtained by orthogonal test design. The effects of different single-doped and co-doped activators on the mechanical properties and hydration mechanism of high content fly ash cementitious system were studied by XRD, FT-IR, TG-DTG, SEM and other test methods. The results show that Na₂SiO₃ has the best activation effect on the high content fly ash composite cementitious system in the single-doped activator. When Na₂SiO₂ content is 1.0% (mass fraction), 7 and 28 d compressive strength of high content fly ash composite cementitious system is 17.5 and 31.7 MPa, respectively. The optimal mass ratio of multiple activators to the excitation effect of high content fly ash cementitious system is m(slag powder)∶m(fly ash)=1∶3. The compressive strength of 7 and 14 d is 27.5 and 35.5 MPa, respectively. The compressive strength of 28 d is increased to 49.2 MPa, reaching the strength index of 42.5 cement. This is due to the secondary pozzolanic reaction of the active substances of fly ash in alkaline environment, and the hydration products such as AFt and C-(A)-S-H gradually increase, which significantly enhances the compressive strength of the cementitious material. This study not only provides a new way for the high-content utilization of fly ash, but also provides a reference for the research and development of solid waste composite materials.

Key words: fly ash, chemical activator, orthogonal test, compressive strength, hydration mechanism

CLC Number:

TU526

DOU Zhanshuang, LI Xiaomin, QIN Hongtao, WEI Dingbang, WU Xu, YAN Sheng, ZHANG Fuqiang, HAN Fangyuan. Mechanical Properties and Hydration Mechanism of Chemically Activated High Content Fly Ash Composite Cementitious Materials[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2025, 44(1): 243-252.

References

[1] 中国粉煤灰综合利用正全面发展: 粉煤灰材料分会2020年度行业发展报告[J]. 混凝土世界, 2021(10): 28-29.
Comprehensive utilization of fly ash is developing in an all-round way in China—industry development report of fly ash materials branch in 2020[J]. China Concrete, 2021(10): 28-29 (in Chinese).
[2] 王晓丽, 李秋义, 陈帅超, 等. 工业固体废弃物在新型建材领域中的应用研究与展望[J]. 硅酸盐通报, 2019, 38(11): 3456-3464.
WANG X L, LI Q Y, CHEN S C, et al. Application research and prospect of industrial soild waste in new building materials[J]. Bulletin of the Chinese Ceramic Society, 2019, 38(11): 3456-3464 (in Chinese).
[3] 乔亮, 兰天翔, 李绪萍, 等. 粉煤灰综合利用研究现状及发展建议[J]. 中国煤炭工业, 2021(4): 64-65.
QIAO L, LAN T X, LI X P, et al. Research status and development suggestions of comprehensive utilization of fly ash[J]. China Coal Industry, 2021(4): 64-65 (in Chinese).
[4] 李茂辉, 杨志强, 王有团, 等. 粉煤灰复合胶凝材料充填体强度与水化机理研究[J]. 中国矿业大学学报, 2015, 44(4): 650-655+695.
LI M H, YANG Z Q, WANG Y T, et al. Experiment study of compressive strength and mechanical property of filling body for fly ash composite cementitious materials[J]. Journal of China University of Mining & Technology, 2015, 44(4): 650-655+695 (in Chinese).
[5] 唐力军, 刘卫东, 陈凯伦. 超细活性粉煤灰对碱激发矿渣体系的影响研究[J]. 粉煤灰综合利用, 2022, 36(4): 92-97.
TANG L J, LIU W D, CHEN K L. Study on the effect of reactive ultra-fine fly ash on alkali-activated slag system[J]. Fly Ash Comprehensive Utilization, 2022, 36(4): 92-97 (in Chinese).
[6] 庄培镇. 碱激发粉煤灰/矿渣微观力学性能的研究[D]. 广州: 广州大学, 2023.
ZHUANG P Z. Study on micromechanical properties of alkali-activated fly ash/slag[D]. Guangzhou: Guangzhou University, 2023 (in Chinese).
[7] 杨达, 庞来学, 宋迪, 等. 粉煤灰对碱激发矿渣/粉煤灰体系的作用机理研究[J]. 硅酸盐通报, 2021, 40(9): 3005-3011.
YANG D, PANG L X, SONG D, et al. Reaction mechanism of fly ash in alkali-activated slag/fly ash system[J]. Bulletin of the Chinese Ceramic Society, 2021, 40(9): 3005-3011 (in Chinese).
[8] 童国庆, 张吾渝, 高义婷, 等. 碱激发粉煤灰地聚物的力学性能及微观机制研究[J]. 材料导报, 2022, 36(4): 129-134.
TONG G Q, ZHANG W Y, GAO Y T, et al. Mechanical properties and micromechanism of alkali-activated fly ash geopolymer[J]. Materials Reports, 2022, 36(4): 129-134 (in Chinese).
[9] 程国东, 黄天勇, 刘泽, 等. 粉煤灰-矿渣基地聚合物胶砂性能研究[J]. 新型建筑材料, 2020, 47(1): 50-53.
CHENG G D, HUANG T Y, LIU Z, et al. Research on the performance of ash-slag based geopolymer mortar[J]. New Building Materials, 2020, 47(1): 50-53 (in Chinese).
[10] 彭玉清, 郭荣鑫, 林志伟, 等. 粉煤灰-矿渣基地聚合物砂浆凝结时间及力学性能试验研究[J]. 新型建筑材料, 2021, 48(12): 138-144.
PENG Y Q, GUO R X, LIN Z W, et al. Experimental study on setting time and mechanical properties of fly ash-slag geopolymer mortar[J]. New Building Materials, 2021, 48(12): 138-144 (in Chinese).
[11] 张琰, 刘华清, 刘佳龙, 等. 三异丙醇胺-碳酸钠协同激发矿渣-粉煤灰体系的力学性能和水化历程[J]. 新型建筑材料, 2022, 49(7): 104-109.
ZHANG Y, LIU H Q, LIU J L, et al. Mechanical property and hydration kinetics of slag-fly ash blends activated with triisopropanolamine and sodium carbonate[J]. New Building Materials, 2022, 49(7): 104-109 (in Chinese).
[12] 刘淑贤, 苏严, 杨敏, 等. 钢渣: 矿渣复合胶凝材料的制备及胶凝活性激发试验研究[J]. 金属矿山, 2022(11): 252-258.
LIU S X, SU Y, YANG M, et al. Experimental study on preparation of the steel slag and slag composite cementitious material and its gelling activity inspiration[J]. Metal Mine, 2022(11): 252-258 (in Chinese).
[13] 肖力光, 雒锋, 王淑娟. 镁渣胶凝材料强度影响因素的研究[J]. 建筑材料学报, 2011, 14(5): 680-684.
XIAO L G, LUO F, WANG S J. Study of factors influencing strength of magnesium slag cementitious material[J]. Journal of Building Materials, 2011, 14(5): 680-684 (in Chinese).
[14] 卢前明, 王震, 张瑞林, 等. 化学外加剂对粉煤灰-矿渣-水泥胶凝体系的激发作用[J]. 硅酸盐通报, 2018, 37(8): 2516-2521.
LU Q M, WANG Z, ZHANG R L, et al. Excitation function of chemical admixture on fly ash-slag-cement cementitious system[J]. Bulletin of the Chinese Ceramic Society, 2018, 37(8): 2516-2521 (in Chinese).
[15] 孙国文, 汤青青, 张丽娟, 等. 大掺量粉煤灰早期活性激发及其作用机理[J]. 哈尔滨工程大学学报, 2019, 40(3): 540-547.
SUN G W, TANG Q Q, ZHANG L J, et al. Early activation effect and mechanism of high-volume fly ash[J]. Journal of Harbin Engineering University, 2019, 40(3): 540-547 (in Chinese).
[16] 李东旭. 低钙粉煤灰在不同碱环境中的活化研究[J]. 材料导报, 2000, 14(11): 59-61.
LI D X. Study of activation of low calcium fly ash in the different alkali surroundings[J]. Materials Review, 2000, 14(11): 59-61 (in Chinese).
[17] 蔡跃波, 罗睿, 王昌义. 水泥-磨细矿渣水化产物—F盐的微结构分析[J]. 水利水运工程学报, 2001(1): 45-49.
CAI Y B, LUO R, WANG C Y. Microstructure analysis on Friedel's salt in hydrate of cement and GGBS[J]. Hydro-Science and Engineering, 2001(1): 45-49 (in Chinese).
[18] 魏威, 高彦斌, 陈忠清, 等. 室温碱激发低钙粉煤灰地质聚合物配比试验研究[J]. 硅酸盐通报, 2020, 39(12): 3889-3896.
WEI W, GAO Y B, CHEN Z Q, et al. Experimental study on proportion of room temperature alkali-activated low-calcium fly ash geopolymer[J]. Bulletin of the Chinese Ceramic Society, 2020, 39(12): 3889-3896 (in Chinese).
[19] 王露, 刘数华. 钙矾石相的研究综述[J]. 混凝土, 2013(8): 83-86+90.
WANG L, LIU S H. Research review on ettringite phase[J]. Concrete, 2013(8): 83-86+90 (in Chinese).
[20] WANG C Q, TAN K F, XU X X, et al. Effect of activators, admixtures and temperature on the early hydration performance of desulfurization ash[J]. Construction and Building Materials, 2014, 70: 322-331.
[21] 白二雷, 许金余, 李浩, 等. 碱激发剂对矿渣粉煤灰活性激发特性影响试验研究[J]. 科学技术与工程, 2014, 14(1): 96-99.
BAI E L, XU J Y, LI H, et al. Experiment study on the stimulating characteristics of slag-fly ash cementitious material system to different alkali-activator[J]. Science Technology and Engineering, 2014, 14(1): 96-99 (in Chinese).
[22] 施惠生, 夏明, 郭晓潞. 粉煤灰基地聚合物反应机理及各组分作用的研究进展[J]. 硅酸盐学报, 2013, 41(7): 972-980.
SHI H S, XIA M, GUO X L. Research development on mechanism of fly ash-based geopolymer and effect of each component[J]. Journal of the Chinese Ceramic Society, 2013, 41(7): 972-980 (in Chinese).
[23] 南雪丽, 杨旭, 张宇, 等. 钢渣-矿渣基胶凝材料的协同水化机理[J]. 建筑材料学报, 2024, 27(4): 366-374.
NAN X L, YANG X, ZHANG Y, et al. Synergistic hydration mechanism of steel slag-slag based cementitious material[J]. Journal of Building Materials, 2024, 27(4): 366-374 (in Chinese).
[24] 杨达. 碱激发矿渣/粉煤灰胶凝材料的性能与水化机理研究[D]. 济南: 山东交通学院, 2022.
YANG D. Study on properties and hydration mechanism of alkali activated GGBS/FA cementitious material[D]. Jinan: Shandong Jiaotong University, 2022 (in Chinese).
[25] 朱庚杰, 朱万成, 齐兆军, 等. 固废基充填胶凝材料配比分步优化及其水化胶结机理[J]. 工程科学学报, 2023, 45(8): 1304-1315.
ZHU G J, ZHU W C, QI Z J, et al. Step optimization of a solid waste-based binder for backfill and a study on hydration and cementation mechanism[J]. Chinese Journal of Engineering, 2023, 45(8): 1304-1315 (in Chinese).