Effect of aqueous phase condition on the strength increasing of cement stabilized soil
-
摘要: 对于同种土样形成的固化土,水泥掺量增加到一定程度后单位水泥量产生的固化土抗压强度增量会显著提高;物理性质相近的土样掺加等量的水泥后固化土抗压强度有显著的差异.为解释上述试验现象,测定了相应固化土孔隙液中主要离子的浓度,并进行热力学计算.结果表明:水泥掺量较少时,固化土孔隙液中Ca(OH)2不饱和,单位水泥量水化生成的胶凝性物质量较少,故产生的固化土抗压强度增量也较小;当土样中水泥掺量达到一定程度后,固化土孔隙液中Ca(OH)2饱和,固化土中胶凝性物质能充分生成,单位水泥量产生的固化土抗压强度增量较大.物理性质相近的土样掺加相同的水泥量,固化土孔隙液中Ca(OH)2离子浓度不同,故而固化土抗压强度也不同.Abstract: The strength increment of stabilized soil generated by unit cement content would remarkably increase after cement content reached to a certain amount, and at same cement content there existed obviously strength difference between the stabilized soil samples formated from different soil samples with same physical characteristics. In order to find the reason of these experimental results, concentrations of main ions in the pore solutions squeezed from the stabilized soil samples were measured, and the concentrations of Ca(OH)2 in the pore solutions with many ions were calculated by the thermodynamic method. The result shows that when cement content is not enough to ensure the Ca(OH)2 reach to saturation,the gel generated by unit cement hydration is less, therefore the strength of the stabilized soil is lower; When cement content reaches to a certain amount, the concentration of Ca(OH)2 in the pore solutions reaches to saturation, the gel can be sufficiently generated, therefore the strength increment of stabilized soil generated by unit cement content remarkably increases. At same cement content the concentrations of Ca(OH)2 in the pore solutions are various, so there are strength difference between the stabilized soil samples with same physical characteristics.
-
Key words:
- cement stabilized soil /
- compressive strength /
- pore solution /
- ion concentration /
- saturation
-
[1] 《地基处理手册》(第二版)编写委员会.地基处理手册[M].第二版.北京:中国建筑工业出版社,2000:110-112 The Compiling Committee of the Handbook of Foundation Treatment. The handbook of foundation treatment[M]. Second Edition. Beijing:Chinese Construction Industry Publishing House, 2000:110-112(in Chinese) [2] Saitoh S, Suzuki Y, Shirai K. Hardening of soil improved by deep mixing method[J].Takenaka Tech Res Rep,1986(36):141-147 [3] Bell F G. Cement stabilization and clay soils, with examples[J].Environmental & Engineering Geoscience,1995,1(2):139-151 [4] Mohamed A M O.Role of clay minerals in marly soils on its stability[J].Engineering Geology,2000,57(3):193-203 [5] Huang X. On suitability of stabilizer based on chemical analysis of the liquid from stabilized soil[J]. Proceedings of the International Conference on Soil Mechanics and Foundation Engineering-International Society for Soil Mechanics Foundation Engineering,1997,3(14):1613-1616 [6] 宁建国,黄新.固化土结构形成及强度增长机理试验[J].北京航空航天大学学报,2006,32(1):97-102 Ning Jianguo, Huang Xin. Experiment on structural formation and mechanism of strength increasing of stabilized soil[J]. Journal of Beijing University of Aeronautics and Astronautics,2006,32(1):97-102(in Chinese) [7] 薛君玕,许温葭,叶铭勋.硬化水泥浆体孔隙中孔隙液的分离和研究[J].硅酸盐学报,1983,11(3):276-289 Xue Jungan, Xu Wenxia, Ye Mingxun. A study of the liquid phase separated from the pores of hardened cement paste[J]. Journal of the Chinese Ceramic Society,1983,11(3):276-289(in Chinese) [8] 黄新, 周国钧. 水泥加固土硬化机理初探[J]. 岩土工程学报, 1994,16(1):62-68 Huang Xin, Zhou Guojun. Hardening mechanism of cement-stabilized soil[J].Chinese Journal of Geotechnical Engineering,1994,16(1):62-68(in Chinese) [9] Thomas J J, Rothstein D, Jennings H M, et al. Effect of hydration temperature on the solubility behavior of Ca-, S-, Al-,and Si-bearing solid phases in portland cement pastes[J].Cement and Concrete Research,2003,33(12):2037-2047 [10] Rothstein D,Thomas J J,Christensen B J,et al. Solubility behavior of Ca-, S-,Al-, and Si-bearing solid phases in portland cement pore solutions as a function of hydration time[J]. Cement and Concrete Research,2002,32(10):1663-1671 [11] 李保山.基础化学[M].北京:科学出版社, 2003:98-99 Li Baoshan.Basal chemistry[M].Beijing:Science Press, 2003:98-99(in Chinese) [12] Borjesson S, Emren A. Passiphic:a program for solubility calculations involving complex solids[J]. Computers & Geosciences,1998,24(9):839-846 [13] Croft J B. The influence of soil mineralogical composition on cement stabilization[J]. Geotechnique,1967,17(2):117-135 [14] Mitsunori Kawamura, Shigemasa Hasaba, Seiji Sugiura. A function of free lime and characteristics clay-cement mixtures[J]. Proc of JSCE,1971(191):117-131
点击查看大图
计量
- 文章访问数: 3111
- HTML全文浏览量: 189
- PDF下载量: 680
- 被引次数: 0