活化牡蛎壳固化余泥渣土及其机理分析

硅酸盐通报 ›› 2021, Vol. 40 ›› Issue (3): 900-906.

活化牡蛎壳固化余泥渣土及其机理分析

许颖, 陈锐, 韦其颖, 徐婷婷

哈尔滨工业大学(深圳),深圳市城市与土木工程防灾减灾重点实验室,深圳 518055

收稿日期:2020-10-16 修回日期:2020-11-24 出版日期:2021-03-15 发布日期:2021-04-13
作者简介:许颖(1977—),女,博士,副教授。主要从事FRP、结构健康监测、光纤传感器、新型结构和新材料结构的研究。E-mail:cexyx@hotmail.com
基金资助:
国家自然科学基金面上项目(52078173)

Activated Oyster Shell for Solidification of Residual Soil and Its Mechanism Analysis

XU Ying, CHEN Rui, WEI Qiying, XU Tingting

Shenzhen Key Lab of Urban & Civil Engineering Disaster Prevention & Reduction, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China

Received:2020-10-16 Revised:2020-11-24 Online:2021-03-15 Published:2021-04-13

摘要/Abstract

摘要： 为实现牡蛎壳和余泥渣土两种固废资源的利用,提出了预处理的牡蛎壳经磷酸或磷酸氢二铵(DAP)活化后固化土体,制得牡蛎壳固化土。试验测定了不同配比的牡蛎壳固化土的力学性能,研究牡蛎壳固化土的边坡抗冲刷性能,并使用扫描电镜和X射线衍射仪观察固化土的微观结构,分析其固化机理。结果表明,掺磷酸、DAP能提高牡蛎壳固化土的抗压强度,其中掺加DAP的效果更好。材料最佳配比(质量分数)为:73.6%土,18.4%牡蛎壳(粒径≤1 mm),8%DAP。其烘干抗压强度达到2.14 MPa,是牡蛎壳稳定余泥渣土抗压强度的2.43 倍,软化系数达到0.5,改变了原土遇水崩解的特性。在室内边坡冲刷试验中,掺DAP牡蛎壳固化土与素土相比,有效降低了坡面冲刷的产沙量。微观结构分析表明,磷酸、DAP分别与牡蛎壳作用生成磷酸钙晶体、羟基磷灰石,两者都能胶结土粒,从而固化土体。

关键词: 余泥渣土, 活化牡蛎壳, 固化土, 边坡抗冲刷性能, 固化机理

Abstract: In order to realize the utilization of the two solid waste resources of oyster shell and residual soil, it was proposed that the pretreated oyster shell was activated by phosphoric acid or diammonium hydrogen phosphate (DAP) to obtain the oyster shell solidified soil. The mechanical properties of oyster shell solidified soil with different ratios were measured and the scouring resistance of slope was studied. The scanning electron microscope and X-ray diffraction were used to observe the microstructure of solidified soil and analyze its solidification mechanism. The results show that the addition of phosphoric acid or DAP improves the compressive strength of oyster shell solidified soil, and the effect of adding DAP is better. The best ratio (mass fraction) of materials is: 73.6% soil, 18.4% oyster shell (particle size ≤1 mm), 8% DAP. Under the optimum ratio condition, the drying compressive strength reaches 2.14 MPa, which is 2.43 times of the compressive strength of oyster shell stabilized residual soil, and the softening coefficient reaches 0.5, which changes the disintegration characteristics of the original soil when exposes to water.In indoor slope scour test, the oyster shell solidified soil mixed with DAP effectively reduces the amount of sand produced by the erosion of slope compared with the plain soil. Microstructure analysis shows that phosphoric acid or DAP interacts with oyster shell to form calcium phosphate crystals and hydroxyapatite. The new products can cement soil particles and solidify the soil.

Key words: residual soil, activated oyster shell, solidified soil, scouring resistance of slope, solidification mechanism

中图分类号:

TU521

许颖, 陈锐, 韦其颖, 徐婷婷. 活化牡蛎壳固化余泥渣土及其机理分析[J]. 硅酸盐通报, 2021, 40(3): 900-906.

XU Ying, CHEN Rui, WEI Qiying, XU Tingting. Activated Oyster Shell for Solidification of Residual Soil and Its Mechanism Analysis[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(3): 900-906.

参考文献

[1] 徐硕,陈宇,丁梁.深圳市余泥渣土处理现状及应对策略研究[C]//规划60年:成就与挑战——2016中国城市规划年会论文集(02城市工程规划).北京:中国城市规划学会,2016:483-491.
XU S, CHEN Y, DING L. Study on the status and countermeasures of waste sludge treatment in Shenzhen[C]//60 Years of Planning: Achievements and Challenges-Proceedings of the 2016 China Urban Planning Annual Meeting (02 Urban Engineering Planning). Beijing: Chinese Urban Planning Society, 2016: 483-491 (in Chinese).
[2] 赵娟,杨耐德,周亮.牡蛎壳资源开发利用综述[J].安徽农学通报,2015,21(21):79-80.
ZHAO J, YANG N D, ZHOU L. Development and utilization of oyster shell resources[J]. Anhui Agricultural Science Bulletin, 2015, 21(21): 79-80 (in Chinese).
[3] MORAVEJ S, HABIBAGAHI G, NIKOOEE E, et al. Stabilization of dispersive soils by means of biological calcite precipitation[J]. Geoderma, 2018, 315: 130-137.
[4] 刘俊霞,张磊,杨久俊,等.磷酸对黄河泥沙石灰土的激活效果及作用机理[J].建筑材料学报,2013,16(5):898-902.
LIU J X, ZHANG L, YANG J J, et al. Activation effect and mechanism of phosphoric acid on Yellow River sediment limes soil[J]. Journal of Building Materials, 2013, 16(5): 898-902 (in Chinese).
[5] YAMADA M, TANIGUCHI K, OKUMURA M, et al. Deflection properties of pavement constructed on subgrade containing crushed oyster shell[J]. Journal of the Society of Materials Science, Japan, 2004, 53(1): 25-28.
[6] LEE S, YOON G, LEE Y, et al. Shear strength characteristics of dredged soil with oyster shell binder[J]. Journal of the Korean Geo-Environmental Society, 2007, 8(1): 27-32.
[7] MOTOHEI K, MASATAKA A, MASAMI O. Cementation of soil due to microbial activity using waste oyster shell[J]. Journal of the Clay Science Society of Japan, 2013, 52(1): 1-8 (in Japanese).
[8] DJOBO J N Y, TCHAKOUTÉ H K, RANJBAR N, et al. Gel composition and strength properties of alkali-activated oyster shell-volcanic ash: effect of synthesis conditions[J]. Journal of the American Ceramic Society, 2016, 99(9): 3159-3166.
[9] 侍倩,李翠华.酸、碱对粘土物理性质的影响的试验研究[J].武汉大学学报(工学版),2001,34(5):84-87.
SHI Q, LI C H. Laboratory study on effects of acid and alkali upon physical properties of clay[J]. Engineering Journal of Wuhan University, 2001, 34(5): 84-87 (in Chinese).
[10] 张登良.加固土原理[M].北京:人民交通出版社,1990:6-94.
ZHANG D L. Principle of reinforcement soil[M]. Beijing: People’s Communications Press, 1990: 6-94 (in Chinese).
[11] 郭金星.新型石灰石土抗压强度试验及微观机理研究[D].淮南:安徽理工大学,2017:12-13.
GUO J X. Study on the compressive strength and micro-mechanism of new limestone soil[D]. Huainan: Anhui University of Science & Technology, 2017: 12-13 (in Chinese).
[12] MA X, BALONIS M, PASCO H, et al. Evaluation of hydroxyapatite effects for the consolidation of a Hellenistic-Roman rock-cut chamber tomb at Athienou-Malloura in Cyprus[J]. Construction and Building Materials, 2017, 150: 333-344.