Mechanical Properties and Road Performance of Slag-Fly Ash Geopolymer Stabilized Sludge

Abstract

Abstract: River sludge is usually stabilized with cementitious binder and applied in pavement construction as sub-ground soil for sustainable treatment. However, the application of Ca-based binder, such as Portland cement and lime, is increasingly limited by the high energy consumption and CO₂ emission. To solve this problem, granulated blast furnace slag (GBFS) and fly ash were used to synthesize binary-phases based geopolymer to stabilize sludge. Firstly, the mix proportion of geopolymer stabilizer was determined based on the influence of Si/Al and Na/Al molar ratio on the setting time and compressive strength of geopolymer. Subsequently, the effects of geopolymer content and curing age on the mechanical properties of stabilized sludge are studied, and the practical performance of stabilized sludge was evaluated with water stability, CBR, dry shrinkage and temperature shrinkage tests. Furthermore, the stabilization mechanism was revealed by the microstructure characterization with scanning electron microscopy and X-ray diffractometry. The experimental results show that the geopolymerization products include amorphous geopolymer gel, calcium silicate hydrate and calcium aluminate hydrate, which enhance the binding of soil particles and filled the voids, and thus improve the mechanical properties and road performance of stabilized sludge. It provides experimental foundation for the practical application of geopolymer stabilized sludge in pavement construction.

Key words: stabilized sludge, slag-fly ash geopolymer, unconfined compressive strength, water stability, dry shrinkage, temperature shrinkage, stabilization mechanism, roadbed material

CLC Number:

TU52

YANG Zhenjia, HE Meng, WU Yang, SHI Yupeng, SUN Liang, PAN Zhu, ZHANG Mo. Mechanical Properties and Road Performance of Slag-Fly Ash Geopolymer Stabilized Sludge[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2022, 41(2): 693-703.

References

[1] 丁慧,孙秀丽,刘文化,等.固化疏浚淤泥作路基材料工程特性试验研究[J].土木建筑与环境工程,2017,39(2):11-18.
DING H, SUN X L, LIU W H, et al. Experimental analysis of engineering properties of solidified sludge as roadbed filling material[J]. Journal of Civil, Architectural & Environmental Engineering, 2017, 39(2): 11-18 (in Chinese).
[2] 汤怡新,刘汉龙,朱伟.水泥固化土工程特性试验研究[J].岩土工程学报,2000,22(5):549-554.
TANG Y X, LIU H L, ZHU W. Study on engineering properties of cement-stabilized soil[J]. Chinese Journal of Geotechnical Engineering, 2000, 22(5): 549-554 (in Chinese).
[3] 贾尚华,申向东,解国梁.石灰-水泥复合土增强机制研究[J].岩土力学,2011,32(s1):382-387.
JIA S H, SHEN X D, XIE G L. Reinforecment mechanism of lime-cement soil[J]. Rock and Soil Mechanics, 2011, 32(s1): 382-387 (in Chinese).
[4] 杨爱武,杜东菊,赵瑞斌,等.水泥及其外加剂固化天津海积软土的试验研究[J].岩土力学,2007,28(9):1823-1827.
YANG A W, DU D J, ZHAO R B, et al. Experimental study on cement and its additional agent to cure Tianjin marine soft soil[J]. Rock and Soil Mechanics, 2007, 28(9): 1823-1827 (in Chinese).
[5] POURAKBAR S, HUAT B B K. Laboratory-scale model of reinforced alkali-activated agro-waste for clayey soil stabilization[J]. Advances in Civil Engineering Materials, 2017, 6(1): 20160023.
[6] 李芳菲,华渊,刘文化,等.干湿循环条件下水泥固化疏浚淤泥的物理力学特性[J].硅酸盐通报,2019,38(2):344-350.
LI F F, HUA Y, LIU W H, et al. Physico-mechanical characteristics of cement-solidified dredged sludge under drying and wetting cycle[J]. Bulletin of the Chinese Ceramic Society, 2019, 38(2): 344-350 (in Chinese).
[7] 秦川,刘松玉,杜广印,等.淤泥质土的整体碳化固化模型试验研究[J].工程地质学报,2019,27(6):1302-1310.
QIN C, LIU S Y, DU G Y, et al. Model tests on mass carbonation stabilization of mucky soil[J]. Journal of Engineering Geology, 2019, 27(6): 1302-1310 (in Chinese).
[8] MCLELLAN B C, WILLIAMS R P, LAY J, et al. Costs and carbon emissions for geopolymer pastes in comparison to ordinary Portland cement[J]. Journal of Cleaner Production, 2011, 19(9/10): 1080-1090.
[9] 田亮,姚晓,董洁,等.矿渣碱激发胶凝材料固化盐渍土试验研究[J].混凝土与水泥制品,2018(9):98-101.
TIAN L, YAO X, DONG J, et al. Experimental study on solidification of saline soil using alkali-activated slag materials[J]. China Concrete and Cement Products, 2018(9): 98-101 (in Chinese).
[10] 黄煜镔,张凯,周静静,等.流化床燃煤固硫灰固化淤泥质土路用性能研究[J].应用基础与工程科学学报,2019,27(2):375-383.
HUANG Y B, ZHANG K, ZHOU J J, et al. Experiment study on the road performances of muddy soil cured by fluidized bed combustion ashes[J]. Journal of Basic Science and Engineering, 2019, 27(2): 375-383 (in Chinese).
[11] 乔京生,王旭影,王冠泓,等.粒化高炉矿渣微粉固化淤泥质土的动力特性及微观机理[J].硅酸盐通报,2021,40(7):2306-2312.
QIAO J S, WANG X Y, WANG G H, et al. Dynamic characteristics and microscopic mechanism of muddy clay solidified by ground granulated blast-furnace slag[J]. Bulletin of the Chinese Ceramic Society, 2021, 40(7): 2306-2312 (in Chinese).
[12] 吴俊,征西遥,杨爱武,等.矿渣-粉煤灰基地质聚合物固化淤泥质黏土的抗压强度试验研究[J].岩土力学,2021,42(3):647-655.
WU J, ZHENG X Y, YANG A W, et al. Experimental study on the compressive strength of muddy clay solidified by the one-part slag-fly ash based geopolymer[J]. Rock and Soil Mechanics, 2021, 42(3): 647-655 (in Chinese).
[13] 孙秀丽,童琦,刘文化,等.碱激发粉煤灰和矿粉改性疏浚淤泥力学特性及显微结构研究[J].大连理工大学学报,2017,57(6):622-628.
SUN X L, TONG Q, LIU W H, et al. Study of microstructure and mechanical properties of dredged silt solidified using fly ash and slag stimulated by alkali[J]. Journal of Dalian University of Technology, 2017, 57(6): 622-628 (in Chinese).
[14] PHETCHUAY C, HORPIBULSUK S, ARULRAJAH A, et al. Strength development in soft marine clay stabilized by fly ash and calcium carbide residue based geopolymer[J]. Applied Clay Science, 2016, 127/128: 134-142.
[15] ARULRAJAH A, MOHAMMADINIA A, D’AMICO A, et al. Cement kiln dust and fly ash blends as an alternative binder for the stabilization of demolition aggregates[J]. Construction and Building Materials, 2017, 145: 218-225.
[16] ELKHEBU A, ZAINORABIDIN A, HJ BAKAR I, et al. Alkaline activation of clayey soil using potassium hydroxide & fly ash[J]. International Journal of Integrated Engineering, 2018, 10(9): 99-104.
[17] LATIFI N, VAHEDIFARD F, SIDDIQUA S, et al. Solidification-stabilization of heavy metal-contaminated clays using gypsum: multiscale assessment[J]. International Journal of Geomechanics, 2018, 18(11): 04018150.
[18] MUHAMMAD N, SIDDIQUA S, LATIFI N. Solidification of subgrade materials using magnesium alkalinization: a sustainable additive for construction[J]. Journal of Materials in Civil Engineering, 2018, 30(10): 04018260.
[19] 徐杨.城市河道淤泥特性及其资源化利用技术研究[D].南京:南京大学,2015:40-43.
XU Y. Geotechnical characterization and beneficial utilization of urban river sediments[D]. Nanjing: Nanjing University, 2015: 40-43 (in Chinese).
[20] KUMAR S, KUMAR R, MEHROTRA S P. Influence of granulated blast furnace slag on the reaction, structure and properties of fly ash based geopolymer[J]. Journal of Materials Science, 2010, 45(3): 607-615.
[21] ISMAIL I, BERNAL S A, PROVIS J L, et al. Modification of phase evolution in alkali-activated blast furnace slag by the incorporation of fly ash[J]. Cement and Concrete Composites, 2014, 45: 125-135.
[22] KAZEMIAN A, GHOLIZADEH VAYGHAN A, RAJABIPOUR F. Quantitative assessment of parameters that affect strength development in alkali activated fly ash binders[J]. Construction and Building Materials, 2015, 93: 869-876.
[23] 崔宏环,刘卫涛,张立群.土凝岩新型固化剂稳定路基粉质黏土的干缩性能[J].科学技术与工程,2019,19(14):320-328.
CUI H H, LIU W T, ZHANG L Q. Dry shrinkage properties of silty clay stabilized by new solidifying agent of soil tuff[J]. Science Technology and Engineering, 2019, 19(14): 320-328 (in Chinese).
[24] 杜衍庆,王新岐.滨海淤泥固化土路用性能试验研究[J].天津建设科技,2019,29(1):1-5.
DU Y Q, WANG X Q. Experimental study on road performance of coastal mud solidified soil[J]. Tianjin Construction Science and Technology, 2019, 29(1): 1-5 (in Chinese).
[25] 商晓儒.水泥稳定建筑垃圾路面基层的技术性能研究[D].西安:长安大学,2019:77-79.
SHANG X R. Research on technical performance of cement stabilized construction waste pavement base[D]. Xi’an: Chang’an University, 2019: 77-79 (in Chinese).
[26] 柯睿,汪洪星,谈云志,等.冻融循环对固化淤泥土力学性质的影响[J].长江科学院院报,2019,36(8):136-139+145.
KE R, WANG H X, TAN Y Z, et al. Effect of freeze-thaw cycle on mechanical properties of solidified silt[J]. Journal of Yangtze River Scientific Research Institute, 2019, 36(8): 136-139+145 (in Chinese).
[27] REDDY M S, DINAKAR P, RAO B H. Mix design development of fly ash and ground granulated blast furnace slag based geopolymer concrete[J]. Journal of Building Engineering, 2018, 20: 712-722.
[28] 孙海超,王文军,凌道盛.低掺量水泥固化土的力学特性及微观结构[J].浙江大学学报(工学版),2021,55(3):530-538.
SUN H C, WANG W J, LING D S. Mechanical properties and microstructure of solidified soil with low cement content[J]. Journal of Zhejiang University (Engineering Science), 2021, 55(3): 530-538 (in Chinese).
[29] 王东星,王宏伟,邹维列,等.碱激发粉煤灰固化淤泥微观机制研究[J].岩石力学与工程学报,2019,38(s1):3197-3205.
WANG D X, WANG H W, ZOU W L, et al. Research on micro-mechanisms of dredged sludge solidified with alkali-activated fly ash[J]. Chinese Journal of Rock Mechanics and Engineering, 2019, 38(s1): 3197-3205 (in Chinese).
[30] 何俊,王小琦,石小康,等.碱渣-矿渣固化淤泥的无侧限抗压强度与微观特征[J].应用基础与工程科学学报,2021,29(2):376-386.
HE J, WANG X Q, SHI X K, et al. Unconfined compressive strength and microscopic characteristics of soft soil solidified with soda residue and ground granulated blast furnace slag[J]. Journal of Basic Science and Engineering, 2021, 29(2): 376-386 (in Chinese).
[31] WANG D X, GAO X Y, LIU X Q, et al. Strength, durability and microstructure of granulated blast furnace slag-modified magnesium oxychloride cement solidified waste sludge[J]. Journal of Cleaner Production, 2021, 292: 126072.
[32] WANG D X, DI S J, GAO X Y, et al. Strength properties and associated mechanisms of magnesium oxychloride cement-solidified urban river sludge[J]. Construction and Building Materials, 2020, 250: 118933.
[33] 杨爱武,王韬,许再良.石灰及其外加剂固化天津滨海软土的试验研究[J].工程地质学报,2015,23(5):996-1004.
YANG A W, WANG T, XU Z L. Experimental study on lime and its additional agent to cure Tianjin marine soft soil[J]. Journal of Engineering Geology, 2015, 23(5): 996-1004 (in Chinese).