Preparation and Strength Mechanism of Alkali-Activated Fly Ash-Slag-Carbide Slag Based Geopolymer

Abstract

Abstract: In this paper, fly ash, slag and carbide slag were used as precursors, and sodium hydroxide and sodium silicate were used as mixed activators to prepare geopolymer. The effects of precursor ratio and activator parameters on the compressive strength of fly ash-slag-carbide slag based geopolymer were investigated, and the microstructure was observed by mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). It is found that the compressive strength of geopolymer increases first and then decreases with the increase of the carbide slag replacing fly ash content, liquid-solid ratio, and activator modulus. When the carbide slag replacing slag content decreases, or the activator concentration increases, the compressive strength increases continuously. Adding carbide slag in the precursors with appropriate amount to replace fly ash positively affects the geopolymer compressive strength. The total porosity and the large pore proportion of geopolymer are generally negatively correlated with the compressive strength. The higher the strength is, the denser the microstructure of geopolymer is. The optimum ratio of geopolymer derived from the test is 32∶15∶3 for the mass ratio of fly ash, slag and carbide slag, 0.55 for the liquid-solid ratio, 30% (mass fraction) for the activator concentration, and 1.2 for the activator modulus, which corresponds to a 28 d compressive strength of 77.83 MPa.

Key words: geopolymer, carbide slag, fly ash, slag, compressive strength, microstructure

CLC Number:

TU502

LIU Yang, CHEN Xiang, WANG Bowen, LU Naiwei, XIAO Xinxin, LUO Dong. Preparation and Strength Mechanism of Alkali-Activated Fly Ash-Slag-Carbide Slag Based Geopolymer[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2023, 42(4): 1353-1362.

References

[1] 赵立文, 朱干宇, 李少鹏, 等. 电石渣特性及综合利用研究进展[J]. 洁净煤技术, 2021, 27(3): 13-26.
ZHAO L W, ZHU G Y, LI S P, et al. Research progress on characteristics and comprehensive utilization of calcium carbide slag[J]. Clean Coal Technology, 2021, 27(3): 13-26 (in Chinese).
[2] 曹春霞, 王波, 成怀刚, 等. 电石渣及二氧化碳资源化利用现状与展望[J]. 化工矿物与加工, 2022, 51(2): 1-9.
CAO C X, WANG B, CHENG H G, et al. The status and outlook of the resource utilization of calcium carbide slag and carbon dioxide[J]. Industrial Minerals & Processing, 2022, 51(2): 1-9 (in Chinese).
[3] DAVIDOVITS J. Geopolymers and geopolymeric materials[J]. Journal of Thermal Analysis, 1989, 35(2): 429-441.
[4] 赵献辉, 王浩宇, 周博宇, 等. 粉煤灰基地聚物的性能影响因素及其凝胶产物研究进展[J]. 硅酸盐通报, 2021, 40(3): 867-876.
ZHAO X H, WANG H Y, ZHOU B Y, et al. Research development on influencing factors of performances and gel products in fly ash-based geopolymer material[J]. Bulletin of the Chinese Ceramic Society, 2021, 40(3): 867-876 (in Chinese).
[5] SOUTSOS M, BOYLE A P, VINAI R, et al. Factors influencing the compressive strength of fly ash based geopolymers[J]. Construction and Building Materials, 2016, 110: 355-368.
[6] ASSI L N, DEAVER E E, ELBATANOUNY M K, et al. Investigation of early compressive strength of fly ash-based geopolymer concrete[J]. Construction and Building Materials, 2016, 112: 807-815.
[7] NATH P, SARKER P K. Effect of GGBFS on setting, workability and early strength properties of fly ash geopolymer concrete cured in ambient condition[J]. Construction and Building Materials, 2014, 66: 163-171.
[8] PHOO-NGERNKHAM T, PHIANGPHIMAI C, INTARABUT D, et al Low cost and sustainable repair material made from alkali-activated high-calcium fly ash with calcium carbide residue[J]. Construction and Building Materials, 2020, 247: 118543.
[9] MEESALA C R, VERMA N K, KUMAR S. Critical review on fly-ash based geopolymer concrete[J]. Structural Concrete, 2020, 21(3): 1013-1028.
[10] 陈晨, 程婷, 贡伟亮, 等. 粉煤灰地聚物反应体系下的反应动力学研究[J]. 硅酸盐通报, 2016, 35(9): 2717-2723.
CHEN C, CHENG T, GONG W L, et al. Reaction kinetics of fly ash based geopolymer systems[J]. Bulletin of the Chinese Ceramic Society, 2016, 35(9): 2717-2723 (in Chinese).
[11] 段玉杰, 周伟, 姬翔, 等. 水固比对溶胶-凝胶法合成地聚物性能的影响[J]. 水力发电学报, 2020, 39(1): 102-109.
DUAN Y J, ZHOU W, JI X, et al. Effect of water-solid ratio on geopolymer synthesized using sol-gel method[J]. Journal of Hydroelectric Engineering, 2020, 39(1): 102-109 (in Chinese).
[12] 刘进琪, 王世玉, 彭晖, 等. 碱激发剂对粉煤灰基地聚物性能影响研究[J]. 交通科学与工程, 2020, 36(3): 8-13.
LIU J Q, WANG S Y, PENG H, et al. Study on the effect of alkali activator on the properties of fly ash-based geopolymer[J]. Journal of Transport Science and Engineering, 2020, 36(3): 8-13 (in Chinese).
[13] 丁兆洋, 苏群, 李明泽, 等. 水玻璃模数对地聚物再生混凝土力学性能影响[J/OL]. 建筑材料学报, 2022: 1-13 (2022-03-08) [2022-10-20]. https://kns.cnki.net/kcms/detail/31.1764.TU.20220307.0902.002.html.
DING Z Y, SU Q, LI M Z, et al. Water-glass modulus on mechanical properties of geopolymer recycled aggregate concrete[J/OL]. Journal of Building Materials, 2022: 1-13 (2022-03-08) [2022-10-20]. https://kns.cnki.net/kcms/detail/31.1764.TU.20220307.0902.002.html (in Chinese).
[14] 彭晖, 崔潮, 蔡春声, 等. 激发剂浓度对偏高岭土基地聚物性能的影响机制[J]. 复合材料学报, 2016, 33(12): 2952-2960.
PENG H, CUI C, CAI C S, et al. Mechanism of activator concentration influencing properties of metakaolin-based geopolymer[J]. Acta Materiae Compositae Sinica, 2016, 33(12): 2952-2960 (in Chinese).
[15] CHEN K L, LIN W T, LIU W D. Effect of NaOH concentration on properties and microstructure of a novel reactive ultra-fine fly ash geopolymer[J]. Advanced Powder Technology, 2021, 32(8): 2929-2939.
[16] PHETCHUAY C, HORPIBULSUK S, SUKSIRIPATTANAPONG C, et al. Calcium carbide residue: alkaline activator for clay-fly ash geopolymer[J]. Construction and Building Materials, 2014, 69: 285-294.
[17] MA X Q, ZHAO M Q, CHEN D J, et al. Preparation of a novel composite geopolymer based on calcium carbide slag-fly ash and its characterization, mechanism and adsorption properties[J]. Water Science and Technology, 2022, 85(8): 2389-2397.
[18] 万宗华, 张文芹, 刘志超, 等. 电石渣-矿渣复合胶凝材料性能研究[J]. 硅酸盐通报, 2022, 41(5): 1704-1714.
WAN Z H, ZHANG W Q, LIU Z C, et al. Properties of carbide slag-slag composite cementitious material[J]. Bulletin of the Chinese Ceramic Society, 2022, 41(5): 1704-1714 (in Chinese).
[19] 夏琳玲, 吴大志, 陈柯宇. 粉煤灰基地质聚合物的性能研究及机理分析[J]. 水利规划与设计, 2021(4): 79-82+132+137.
XIA L L, WU D Z, CHEN K Y. Study on properties and mechanism of fly ash based geopolymer[J]. Water Resources Planning and Design, 2021(4): 79-82+132+137 (in Chinese).
[20] 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).
[21] ZHANG M H, LI H. Pore structure and chloride permeability of concrete containing nano-particles for pavement[J]. Construction and Building Materials, 2011, 25(2): 608-616.