基于石灰石粉钙源的微生物固化砂土试验研究

doi:10.16108/j.issn1006-7493.2020106

摘要/Abstract

摘要： 微生物诱导碳酸钙沉积（MICP）作用是一种新型的土体改良技术。钙源作为MICP反应中重要的反应物，对微生物诱导碳酸钙沉积的效果有重要的影响。目前应用最广泛的钙源——氯化钙（CaCl2），具有成本高，环境污染性大的缺点。为此，文章提出利用石灰石粉提取钙源，通过在石灰石粉中加入乙酸溶液，释放钙离子用于微生物固化土体。通过开展无侧限抗压强度试验以及微观结构的扫描电镜观测、碳酸钙含量测定等分析，验证利用石灰石粉提取的钙源用于微生物诱导碳酸钙沉积作用固化土体的可行性，同时与醋酸钙和氯化钙固化砂柱进行了对比分析。研究结果表明：（1）石灰石粉用于微生物固化土体具有可行性，固化后砂柱的强度和碳酸钙含量较高，结构完整性高；（2）不同钙源固化砂柱的力学特性不同但均呈典型的脆性破坏模式，其中醋酸钙固化砂柱的无侧限抗压强度略高于石灰石钙源固化砂柱，氯化钙固化砂柱的无侧限抗压强度则远低于前两者且表面更加粗糙，孔隙更多，破坏后的完整性更低；（3）不同钙源固化砂柱的碳酸钙含量不同。醋酸钙和石灰石钙源固化砂柱的碳酸钙含量相近，而氯化钙固化砂柱中碳酸钙含量较低。不同钙源固化砂柱的碳酸钙含量和无侧限抗压强度基本呈正相关关系；（4）醋酸钙和石灰石钙源固化砂柱中砂土颗粒的表面和接触点间均沉积大量碳酸钙，碳酸钙晶体主要为薄片状堆叠的方解石。氯化钙固化砂柱中碳酸钙沉积量低于前两者，碳酸钙晶体主要为六面体状的方解石；（5）不同钙源主要通过影响微生物成矿过程的晶型、晶貌、晶体含量、晶体分布及胶结特征来改变固化效果。

关键词: 微生物诱导碳酸钙沉淀, MICP, 石灰石粉, 强度, 碳酸钙, 微观结构

Abstract: Microbial induced calcite precipitation (MICP) is a new soil improvement technology. As an important reactant in MICP reaction, calcium source has an important effect on the effect of microbial induced calcite precipitation. At present, the most widely used calcium source— calcium chloride (CaCl2), has the disadvantages of high cost and high environmental pollution. Therefore, this paper proposes to extract calcium source from limestone powder by adding acetic acid solution to limestone powder for microbial solidification of soil. The unconfined compressive strength test, scanning electron microscope observation of microstructure and calcium carbonate content test were carried out to verify the feasibility of using calcareous powder to extract calcium source for microbial induced calcite precipitation. The results show that: (1) It is feasible to extract calcium source from limestone powder for microbial solidification of soil. The strength and calcium carbonate content of sand column after solidifying is high and the structural integrity is high. (2) The mechanical properties of solidified sand columns treated by different calcium sources are different. The sand columns solidified by three kinds of calcium show typical brittle failure mode. But the unconfined compressive strength of sand columns solidified by calcium acetate is slightly higher than that of sand columns solidified by calcium source from limestone, and the unconfined compressive strength of sand columns solidified by calcium chloride is much lower than that of the first two. Sand columns solidified by calcium chloride are rougher and have more pores on the surface than the other two. They also have lower integrity after destruction. (3) The content of calcium carbonate in solidified sand columns treated by different calcium sources is different. Sand columns solidified by calcium acetate and calcium source from limestone have almost no difference, but sand columns solidified by calcium chloride have less calcium carbonate content. There is a positive correlation between calcium carbonate content and unconfined compressive strength of sand columns solidified by different calcium sources. (4) A large amount of calcium carbonate is precipitated between the surface and contact point of sand particles in the sand column solidified by calcium acetate and calcium source from limestone. Calcium carbonate crystal is mainly thin stacked calcite. Sand columns solidified by calcium chloride have less calcium carbonate precipitation than the first two, and calcium carbonate crystal is mainly hexagonal calcite. (5) Different calcium sources change the soildifying effect mainly by affecting the crystal appearance, crystal content, crystal distribution and cementation characteristics of microbial mineralization.

Key words: microbial induced calcite precipitation, MICP, limestone power, strength, calcium carbonate, microstructure

中图分类号:

P642

程瑶佳, 唐朝生, 刘博, 泮晓华, 王殿龙, 吕超, 李昊. 基于石灰石粉钙源的微生物固化砂土试验研究[J]. 高校地质学报, 2021, 27(6): 746-753.

CHENG Yaojia, TANG Chaosheng, LIU Bo, PAN Xiaohua, WANG Dianlong, LYU Chao, LI Hao. Experimental Sthdy on Microbial Solidified Sand Based on Calcium Source Extracted from Limestone Powder[J]. Geological Journal of China Universities, 2021, 27(6): 746-753.

[1]	唐朝生, 泮晓华, 吕超, 董志浩, 刘博, 王殿龙, 李昊, 程瑶佳, 施斌. 微生物地质工程技术及其应用[J]. 高校地质学报, 2021, 27(6): 625-654.
[2]	申嘉伟, 周博, 张星, 吏垚, 汪华斌. MICP 对钙质砂单颗粒的破碎行为影响研究[J]. 高校地质学报, 2021, 27(6): 655-661.
[3]	王逸杰, 蒋宁俊. 原位激发微生物成矿加固钙质砂的剪切与压缩特性研究[J]. 高校地质学报, 2021, 27(6): 662-669.
[4]	王殿龙, 唐朝生, 泮晓华, 刘博, 李昊, 吕超, 程瑶佳. 纤维加筋MICP 固化钙质砂的抗拉强度特性研究[J]. 高校地质学报, 2021, 27(6): 670-678.
[5]	尹黎阳, 唐朝生, 张龙. MICP 联合纤维加筋改性钙质砂力学特性研究[J]. 高校地质学报, 2021, 27(6): 679-686.
[6]	周应征, 管大为, 成亮. 微生物诱导碳酸盐在土体加固中的应用进展[J]. 高校地质学报, 2021, 27(6): 697-706.
[7]	黄明, 张瑾璇, 刘子健, 许凯. 南方湿热区产脲酶菌固化海砂的碳酸钙结晶效果研究[J]. 高校地质学报, 2021, 27(6): 716-722.
[8]	泮晓华, 唐朝生, 施斌. 微生物矿化作用改善不同孔隙砂岩抗冻融特性试验研究[J]. 高校地质学报, 2021, 27(6): 723-730.
[9]	路桦铭, 张智超, 肖杨, 马国梁, 叶龙珍. 降雨条件下微生物技术治理崩岗侵蚀[J]. 高校地质学报, 2021, 27(6): 731-737.
[10]	许鹏旭, 温智力, 杨司盟, 刘志明, 冷勐, 彭劼. 不同颗粒尺寸条件下MICP 固化砂土的试验研究[J]. 高校地质学报, 2021, 27(6): 738-745.
[11]	赖汉江, 崔明娟. 基于脲酶诱导碳酸钙沉积固化土体的研究进展[J]. 高校地质学报, 2021, 27(6): 769-774.
[12]	郎钞棚, 马明, 邱立冬, 杨远江, 李明东. 大豆脲酶促沉碳酸钙改良砂土地基承载特性模型试验研究：基于静力触探试验[J]. 高校地质学报, 2021, 27(6): 784-788.
[13]	杨阳, 朱辰, 王洪涛, 花浩, 江锐捷, 毛玮, 赵良. 醇羟基对碳酸钙矿物成核物相及界面能影响研究[J]. 高校地质学报, 2020, 26(6): 617-627.
[14]	李鹏，聂宁，刘强，郝胜利，吴邵芳，杨俊杰. 青岛滨海海积淤泥水泥土力学性能及变形特性试验研究[J]. 高校地质学报, 2020, 26(6): 674-679.
[15]	赵沁华，赵晓豹，郑彦龙，李建春，何磊，刘汉文，余家旺. 微波照射下矿物升温特性与岩石弱化效果研究综述[J]. 高校地质学报, 2020, 26(3): 350-360.

基于石灰石粉钙源的微生物固化砂土试验研究

Experimental Sthdy on Microbial Solidified Sand Based on Calcium Source Extracted from Limestone Powder

PDF (PC)

可视化

摘要/Abstract

引用本文

使用本文

参考文献

相关文章 15

编辑推荐

Metrics