基于磷石膏硫激发作用水泥-石灰固化赤泥,开展了固化赤泥无侧限抗压强度、抗劈裂、抗回弹力学性能和干湿、冻融耐久性能等路用性能的室内试验,探究了该固化赤泥应用道路基层的可行性。试验结果表明:采用固化剂配比m水泥:m石灰:m磷石膏=8:2:2的固化赤泥路用基层性能最佳,7 d无侧限抗压强度为4.18 MPa,满足基层强度要求;28 d劈裂强度和回弹模量分别为0.256、1 020 MPa;五级干湿和冻融循环后,质量变化率<2%,强度损失指标BDR均在80%以上。压汞试验从微观揭示了磷石膏反应产生的钙矾石,通过填充孔隙(0.1~1 μm),增强固化赤泥强度;过量钙矾石使得固化赤泥体积膨胀,产生微裂缝孔隙(1~10 μm),强度性能劣化。综合固化赤泥性能试验结果,使用m赤泥:m水泥:m石灰:m磷石膏=100:8:2:2配合比制备的固化赤泥替代传统路面基层材料是可行的,拓宽了赤泥综合利用的途径。
Abstract
We conducted indoor experimental research to evaluate the unconfined compressive strength, splitting strength, resilient modulus, and dry-wet and freeze-thaw durability of phosphogypsum-activated cement-lime solidified red mud for road applications. The aim was to investigate the feasibility of using this solidified red mud as a road base material. The experimental results demonstrate that the best road base performance is achieved when the curing agent mixing ratio is mcement:mlime:mphosphogypsum=8:2:2. The 7-day unconfined compressive strength reaches 4.18 MPa, meeting the strength requirements of road base. The splitting strength and resilient modulus at 28-day age are 0.256 MPa and 1 020 MPa, respectively. After five cycles of dry-wet and freeze-thaw, the mass change rate is less than 2%, and the strength loss index (BDR) exceeds 80%. Microscopic analysis using a mercury intrusion test reveals that the AFt (ettringite) generated from the reaction of phosphogypsum could enhance the strength of red mud by filling pores (0.1~1 μm) in the solidified red mud. However, excessive AFt causes volumetric expansion and gives rise to micro-crack pores (1~10 μm), resulting in deteriorated strength performance. In conclusion, the performance test results indicate that the solidified red mud prepared with a ratio of mred mud:mcement:mlime:mphosphogypsum=100:8:2:2 can be effectively used as a substitute for traditional pavement base materials. This discovery provides a broader avenue for the comprehensive utilization of red mud.
关键词
赤泥 /
道路工程 /
道路基层 /
无侧限抗压强度 /
路用性能
Key words
red mud /
road engineering /
road base /
unconfined compressive strength /
road performance
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] POWER G, GRÄFE M, KLAUBER C. Bauxite Residue Issues: I. Current Management, Disposal and Storage Practices[J]. Hydrometallurgy, 2011, 108(1/2): 33-45.
[2] XUE S, KONG X, ZHU F, et al. Proposal for Management and Alkalinity Transformation of Bauxite Residue in China[J]. Environmental Science and Pollution Research, 2016, 23(13): 12822-12834.
[3] HUA Y, HEAL K V, FRIESL-HANL W. The Use of Red Mud as an Immobiliser for Metal/Metalloid-contaminated Soil: A Review[J]. Journal of Hazardous Materials, 2017, 325: 17-30.
[4] LI Y W, JIANG J, XUE S G, et al. Effect of Ammonium Chloride on Leaching Behavior of Alkaline Anion and Sodium Ion in Bauxite Residue[J]. Transactions of Nonferrous Metals Society of China, 2018, 28(10): 2125-2134.
[5] LU F, XIAO T, LIN J, et al. Recovery of Gallium from Bayer Red Mud through Acidic-leaching-ion-exchange Process under Normal Atmospheric Pressure[J]. Hydrometallurgy, 2018, 175: 124-132.
[6] KRIVENKO P, KOVALCHUK O, PASKO A, et al. Development of Alkali Activated Cements and Concrete Mixture Design with High Volumes of Red Mud[J]. Construction and Building Materials, 2017, 151: 819-826.
[7] SRIDEVI G, SAHOO S, SEN S. Stabilization of Expansive Soil with Red Mud and Lime[M]∥Lecture Notes in Civil Engineering. Singapore: Springer Singapore, 2018: 259-268.
[8] SUTAR H. Progress of Red Mud Utilization: An Overview[J]. American Chemical Science Journal, 2014, 4(3): 255-279.
[9] DEELWAL K. Evaluation of Characteristic Properties of Red Mud for Possible Use as a Geotechnical Material in Civil Construction[J]. International Journal of Advances in Engineering & Technology, 2014, 7(3): 1053-1059.
[10] MUKIZA E, ZHANG L, LIU X, et al. Utilization of Red Mud in Road Base and Subgrade Materials: a Review[J]. Resources, Conservation and Recycling, 2019, 141: 187-199.
[11] SATYANAYARANA P, NAIDU G. Characterization of Lime Stabilized Red Mud Mix for Feasibility in Road Construction[J]. International Journal of Engineering Research and Development, 2012, 3(7): 20-26.
[12] HANUMANTH RAO C V. Application of GGBS Stabilized Redmud in Road Construction[J]. IOSR Journal of Engineering, 2012, 2(8): 14-20.
[13] SABAT A K,MOHANT AB S.Efficacy of Dolime Fine Stabilized Red Mud-Fly Ash Mixes as Subgrade Material[J]. ARPN Journal of Engineering and Applied Sciences, 2015, 10(14):5919-5923.
[14] 李 辰. 拜耳法赤泥应用于路基填筑基本性能与工程应用研究[D]. 济南: 山东建筑大学, 2018. (LI Chen. Study on Basic Performance and Engineering Application of Bayer Red Mud in Subgrade Filling[D].Jinan: Shandong Jianzhu University, 2018. (in Chinese))
[15] LI Y W, LUO X H, LI C X, et al. Variation of Alkaline Characteristics in Bauxite Residue under Phosphogypsum Amendment[J]. Journal of Central South University, 2019, 26(2): 361-372.
[16] 孙兆云. 拜耳法赤泥填筑路基的工程技术与环境影响研究[D]. 济南: 山东大学, 2017. (SUN Zhao-yun. Research on the Engineering Technology and Environmental Impact of Bayer Red Mud Filling Subgrade[D]. Jinan: Shandong University, 2017. (in Chinese))
[17] KUSHWAHA S S, KISHAN D. Stabilization of Red Mud by Lime, Gypsum and Investigating Its Possible Use as a Geotechnical Material in the Civil Construction[J]. International Journal of Advances in Engineering and Technology, 2014, 7(4): 1238-1244.
[18] ZHANG J, LI C. Experimental Study on Lime and Fly Ash-Stabilized Sintered Red Mud in Road Base[J]. Journal of Testing and Evaluation, 2018, 46(4): 20170215.
[19] 刘晓明, 唐彬文, 尹海峰, 等. 赤泥—煤矸石基公路路面基层材料的耐久与环境性能[J]. 工程科学学报, 2018, 40(4): 438-445. (LIU Xiao-ming, TANG Bin-wen, YIN Hai-feng, et al. Durability and Environmental Performance of Bayer Red Mud-coal Gangue-based Road Base Material[J]. Chinese Journal of Engineering, 2018, 40(4): 438-445.(in Chinese))
[20] 周士琼. 建筑材料[M].2版. 北京:中国铁道出版社, 1991.(ZHOU Shi-qiong. Construction Matetials[M]. Edition 2. Beijing: China Railway Publishing House Co., Ltd., 1991. (in Chinese))
[21] JTG 3430—2020, 公路土工试验规程[S]. 北京: 人民交通出版社, 2020. (JTG 3430—2020, Test Methods of Soils for Highway Engineering[S]. Beijing: China Communications Press, 2020. (in Chinese))
[22] JTG E51—2009, 公路工程无机结合料稳定材料试验规程[S]. 北京: 人民交通出版社, 2009. (JTG E51—2009, Test Methods of Materials Stabilized with Inorganic Binders for Highway Engineering[S]. Beijing: China Communications Press, 2009. (in Chinese))
[23] 童小东, 蒋永生, 龚维明, 等. 石灰在水泥系深层搅拌法中的应用[J]. 工业建筑, 2000, 30(1): 21-25, 30. (TONG Xiao-dong, JIANG Yong-sheng, GONG Wei-ming, et al. Application of Lime in Cement Deep Mixing Method[J]. Industrial Construction, 2000, 30(1): 21-25, 30.(in Chinese))
[24] JTG/T F20—2015, 公路路面基层施工技术细则[S]. 北京: 人民交通出版社, 2015. (JTG/T F20—2015, Technical Guidelines for Construction of Highway Pavement Base[S]. Beijing: China Communications Press, 2015. (in Chinese))
[25] MUKIZA E, ZHANG L L, LIU X M. Durability and Microstructure Analysis of the Road Base Material Prepared from Red Mud and Flue Gas Desulfurization Fly Ash[J]. International Journal of Minerals, Metallurgy and Materials, 2020, 27(4): 555-568.
[26] 潘 浩. 赤泥磷石膏固化重金属污染土的特性和机理研究[D]. 南京: 东南大学, 2020. (PAN Hao. Study on Characteristic and Mechanism of Red Mud and Phosphogysum Solidifying Heavy Metal Contaminated Soil[D]. Nanjing: Southeast University, 2020. (in Chinese))
[27] 刘子铭.基于钙矾石填充的有机质土加固试验研究[D]. 南京: 东南大学, 2017. (LIU Zi-ming. Experimental Study on Reinforcing the Organic Soil Based on the Filling Function of Ettringite[D]. Nanjing: Southeast University, 2017. (in Chinese))
PDF(6841 KB)
