Experimental Study on New Composite Excited Lithium Slag-Based Curing Agent for Reinforcing Soft Soil

Abstract

Abstract: In order to improve the utilization rate of solid waste lithium slag, lithium slag was used as raw material, quick lime was selected as external additive, and calcium carbonate and sodium hydroxide were added as composite activators. A new type of soft soil curing agent material was developed by alkali excitation technology. The curing mix ratio of new composite excited lithium slag-based curing agent (CELS) was studied by orthogonal test, and the influences of various factors on the compressive strength of solidified soil were explored. At the same time, combined with XRD and SEM, the curing mechanism and microstructure evolution between curing agent and soft soil were revealed. The results show that the optimum mixture ratio of curing agent is 73% (mass fraction) of lithium slag, 18% (mass fraction) of lime, 9% (mass fraction) of composite activator, and the mass ratio of calcium carbonate to sodium hydroxide is 1∶1. Under this mix ratio, the unconfined compressive strength of solidified soil at 7 and 28 d is 1.32 and 2.35 MPa, respectively, and the water stability coefficient is 0.80 and 0.87, respectively. Under the synergistic effect of quicklime and composite activator, the cementitious materials such as calcium aluminosilicate hydrate (C-A-S-H) and sodium aluminosilicate hydrate (N-A-S-H) in solidified soil increase significantly, and the density of soil structure increases, thereby improving the strength and water stability of solidified soil.

Key words: lithium slag, curing agent, alkali-activated technology, unconfined compressive strength, water stability, solidified mechanism, microstructure

CLC Number:

X705
TU472

YANG Lin, YANG Jianyu, YANG Weijun. Experimental Study on New Composite Excited Lithium Slag-Based Curing Agent for Reinforcing Soft Soil[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2024, 43(7): 2556-2564.

References

[1] GUO Q, WEI M, WU H, et al. Strength and micro-mechanism of MK-blended alkaline cement treated high plasticity clay[J]. Construction and Building Materials, 2020, 236: 117567.
[2] HASSAN A, ARIF M, SHARIQ M. A review of properties and behaviour of reinforced geopolymer concrete structural elements: a clean technology option for sustainable development[J]. Journal of Cleaner Production, 2020, 245: 118762.
[3] WU H L, JIN F, BO Y L, et al. Leaching and microstructural properties of lead contaminated Kaolin stabilized by GGBS-MgO in semi-dynamic leaching tests[J]. Construction and Building Materials, 2018, 172: 626-634.
[4] WU D Z, ZHANG Z L, CHEN K Y, et al. Experimental investigation and mechanism of fly ash/slag-based geopolymer-stabilized soft soil[J]. Applied Sciences, 2022, 12(15): 7438.
[5] TAN H B, ZHANG X, HE X Y, et al. Utilization of lithium slag by wet-grinding process to improve the early strength of sulphoaluminate cement paste[J]. Journal of Cleaner Production, 2018, 205: 536-551.
[6] CHEN D, HU X, SHI L, et al. Synthesis and characterization of zeolite X from lithium slag[J]. Applied Clay Science, 2012, 59/60: 148-151.
[7] HE Y, CHEN Q S, QI C C, et al. Lithium slag and fly ash-based binder for cemented fine tailings backfill[J]. Journal of Environmental Management, 2019, 248: 109282.
[8] 张兰芳, 陈剑雄, 李世伟. 碱激发矿渣-锂渣混凝土试验研究[J]. 建筑材料学报, 2006, 9(4): 488-492.
ZHANG L F, CHEN J X, LI S W. Examination study of alkali-activated slag-lithium slag concrete[J]. Journal of Building Materials, 2006, 9(4): 488-492 (in Chinese).
[9] LI J Z, LIAN P H, HUANG S W, et al. Recycling of lithium slag extracted from lithium mica by preparing white Portland cement[J]. Journal of Environmental Management, 2020, 265: 110551.
[10] HE Z H, DU S G, CHEN D. Microstructure of ultra high performance concrete containing lithium slag[J]. Journal of Hazardous Materials, 2018, 353: 35-43.
[11] QIN Y J, CHEN J J, LI Z X, et al. The mechanical properties of recycled coarse aggregate concrete with lithium slag[J]. Advances in Materials Science and Engineering, 2019, 2019: 8974625.
[12] NATH S K, MAITRA S, MUKHERJEE S, et al. Microstructural and morphological evolution of fly ash based geopolymers[J]. Construction and Building Materials, 2016, 111: 758-765.
[13] ROSTAMI M, BEHFARNIA K. The effect of silica fume on durability of alkali activated slag concrete[J]. Construction and Building Materials, 2017, 134: 262-268.
[14] WU J, ZHENG X Y, YANG A W, et al. Experimental study on the compressive strength of the one-part slag-fly ash based geopolymer stabilized muddy clay[J]. Rock Soil Mech, 2021, 42(9): 647-655.
[15] RIVERA J, OROBIO A, CRISTELO N, et al. Fly ash-based geopolymer as A4 type soil stabiliser[J]. Transportation Geotechnics, 2020, 25: 100409.
[16] SALIMI M, GHORBANI A. Mechanical and compressibility characteristics of a soft clay stabilized by slag-based mixtures and geopolymers[J]. Applied Clay Science, 2020, 184: 105390.
[17] CHOUBEY P K, KIM M S, SRIVASTAVA R R, et al. Advance review on the exploitation of the prominent energy-storage element: lithium. Part I: from mineral and brine resources[J]. Minerals Engineering, 2016, 89: 119-137.
[18] 王奕仁, 王栋民, 赵计辉, 等. 锂渣-CaO胶凝体系的火山灰反应性研究[J]. 硅酸盐通报, 2020, 39(8): 2501-2507.
WANG Y R, WANG D M, ZHAO J H, et al. Pozzolanic reactivity of lithium slag-CaO cementitious system[J]. Bulletin of the Chinese Ceramic Society, 2020, 39(8): 2501-2507 (in Chinese).
[19] LUO Q, LIU Y T, DONG B Q, et al. Lithium slag-based geopolymer synthesized with hybrid solid activators[J]. Construction and Building Materials, 2023, 365: 130070.
[20] 李保亮, 尤南乔, 曹瑞林, 等. 锂渣粉的组成及在水泥浆体中的物理与化学反应特性[J]. 材料导报, 2020, 34(10): 10046-10051.
LI B L, YOU N Q, CAO R L, et al. Composition of lithium slag powder and its physical and chemical reaction characteristics in cement paste[J]. Materials Reports, 2020, 34(10): 10046-10051 (in Chinese).
[21] ZHOU Y F, LI J S, LU J X, et al. Recycling incinerated sewage sludge ash (ISSA) as a cementitious binder by lime activation[J]. Journal of Cleaner Production, 2020, 244: 118856.
[22] 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.
[23] LIU Z, WANG J X, JIANG Q K, et al. A green route to sustainable alkali-activated materials by heat and chemical activation of lithium slag[J]. Journal of Cleaner Production, 2019, 225: 1184-1193.
[24] 杨振甲, 何猛, 吴杨, 等. 矿渣-粉煤灰地聚物固化淤泥力学性能和路用性能研究[J]. 硅酸盐通报, 2022, 41(2): 693-703+724.
YANG Z J, HE M, WU Y, et al. Mechanical properties and road performance of slag-fly ash geopolymer stabilized sludge[J]. Bulletin of the Chinese Ceramic Society, 2022, 41(2): 693-703+724 (in Chinese).
[25] CONG P, OUYANG Z, HOU R X, et al. Effects of application of microbial fertilizer on aggregation and aggregate-associated carbon in saline soils[J]. Soil & Tillage Research, 2017, 168: 33-41.
[26] YAO J L, QIU H J, HE H, et al. Application of a soft soil stabilized by composite geopolymer[J]. Journal of Performance of Constructed Facilities, 2021, 35(4): 04021018.
[27] 金胜赫, 王修山, 吴越鹏. 矿渣-脱硫石膏-电石渣固化剂固化黏土的研究[J]. 工程地质学报, 2023, 31(2): 397-408.
JIN S H, WANG X S, WU Y P. Study on modification of marine clay treated with new gdc soil stabilizer[J]. Journal of Engineering Geology, 2023, 31(2): 397-408 (in Chinese).
[28] JEON D, JUN Y B, JEONG Y, et al. Microstructural and strength improvements through the use of Na₂CO₃ in a cementless Ca(OH)₂-activated class F fly ash system[J]. Cement and Concrete Research, 2015, 67: 215-225.
[29] 董必钦, 罗小龙, 田凯歌, 等. 碱激发锂渣人造骨料的制备和性能表征[J]. 材料导报, 2021, 35(15): 15011-15016.
DONG B Q, LUO X L, TIAN K G, et al. Preparation and characterization of alkali-activated lithium slag-based artificial aggregates[J]. Materials Reports, 2021, 35(15): 15011-15016 (in Chinese).