Gypsum Induced Strength Behaviour of Fly Ash-Lime Stabilized Expansive Soil

被引：60
作者：
Sivapullaiah P.V. [1 ]
Jha A.K. [1 ]
机构：
[1] Department of Civil Engineering, Indian Institute of Science, Bangalore
来源：
Geotechnical and Geological Engineering | 2014年 / 32卷 / 5期
关键词：
Cementitious; Ettringite; Fly ash; Gypsum; Montmorillonite;
D O I：
10.1007/s10706-014-9799-7
中图分类号：
学科分类号：
摘要：
Physical and engineering properties of soil are improved with various binders and binder combinations. Fly ash and lime are commonly used to improve the properties of expansive soils. An attempt has been made, in this paper, to examine the role of gypsum on the physical and strength behaviour of fly ash-lime stabilized soil. The change in strength behaviour is studied at different curing periods up to 90 days, and the mechanism is elucidated through pH, mineralogical, microstructural and chemical composition study. The strength of soil-fly ash mixture has improved marginally with the addition of lime up to 4 % lime and with curing period for 28 day. Significant increase in strength has been observed with 6 % lime and enhanced significantly after curing for 90 days. The variations in the strength of soil with curing period is due to cation exchange and flocculation initially, and binding of particles with cementitious compounds formed after curing. With addition of 1 % gypsum to soil-fly ash-lime, the strength gain is accelerated as seen at 14 day curing. The accelerated strength early is due to formation of compacted structure with growth of ettringite needles within voids. However, strength at curing for 28 day has been declined due to annoyance of clay matrix with the increase in size of ettringite needle; and again increased after curing for 90 days. The rearrangement of clay matrix and suppression of sulphate effects with formation of cementitious compounds are observed and found to be the main responsible factors for strength recovered. © 2014, Springer International Publishing Switzerland.
引用
收藏
页码：1261 / 1273
页数：12
相关论文
共 53 条
  • [1] Abdi M.R., Wild S., Sulphate expansion of lime-stabilized kaolinite: I. Physical characteristics, Clay Miner, 28, pp. 555-567, (1993)
  • [2] Abduljauwad S.N., Treatment of calcareous expansive clays, Fly ash for soil improvement ASCE geotechnical special publication no, (1993)
  • [3] Acosta H., Edil T.B., Benson C.H., Soil stabilization and drying using fly ash, Geo Eng Rep (03–03), (2003)
  • [4] Al-Mukhtar M., Lasledj A., Alcover J.-F., Behaviour and mineralogy changes in lime-treated expansive soil at 20 °C, Appl Clay Sci, 50, 2, pp. 191-198, (2010)
  • [5] Bell F.G., Lime stabilization of clay minerals and soils, Eng Geol, 42, 4, pp. 223-237, (1996)
  • [6] Bhanumathidas N., Kalidas N., Sustainable Development through use of Fly Ash, Keynote Paper presented at National Seminar on Building Materials &, (2005)
  • [7] Bhuvaneshwari S., Robinson R.G., Gandhi S.R., Stabilization of expansive soils using fly ash. Fly Ash Utilization Programme (FAUP), Technology Information Forecasting & Assessment Council (TIFAC), Department of Science and Technology (DST), (2005)
  • [8] Chen F.H., Foundations on expansive soils, Elsevier, (1975)
  • [9] Christopher B.R., Schwartz C., Boudreau R., Geotechnical aspects of pavements. Washington, DC: US Department of Transportation, Federal Highway Administration, Report Number FHWA NHI-05-037, (2006)
  • [10] Cokca E., Use of class c fly ashes for the stabilizationof an expansive soil, J Geotech Geoenviron Eng, 127, 7, pp. 568-573, (2001)
123456