Pavement geotechnical properties of polymer modified weathered semi-arid shale subgrade
Tóm tắt
The use of non-traditional stabilizers with limited water demand for strength development provide significant cost benefit in geotechnical and pavement engineering applications in arid and semi-arid regions. Series of tests were conducted on weathered clay shales of the Witwatersrand super group from Johannesburg East Rand. The specimens were stabilized with different percentages of acrylic based water borne polymer and cured for between 3 and 56 days at 20°C and 50°C respectively. Atterberg limit, Dry and Soaked UCS, Permeability tests and Mercury intrusion porosimetry (MIP) tests were conducted. The results revealed that the strength and durability of the stabilized shale was very sensitive to the curing temperature, increase of curing temperature from 20°C and 50°C resulted in 150% increase in mobilized strength and 200% increase in soaked strength. The curing period at which the maximum strength was developed was dependent on curing temperature. The optimum properties at high temperature are associated with distribution and abundance of very fine pores < 0.002mm. Modified materials with % binder content greater than 8% and cured for more than 14 days at 50°C, were adequate for pavement subgrade and subbase according to local specification TRH 4 (2008).
Tài liệu tham khảo
A. A Al-khanbashi, S.H.W. Abdalla, Evaluation of three waterborne polymers as stabilizers for sandy soil. Geotechnical Geological Engineering 24 (2006) 1603–1625.
W.A A. Ajayi-Majebi, WA Grissom, L.S Smith, E.E Jones, Epoxy-resin based chemical stabilization of a fine, poorly graded soil system. Transp. Res. Rec. 1295 (1991).
R.L Santoni, J.S Tingle, S.L Webster. Stabilization of silty sand with non-traditional additives, Transp. Res. Rec. 1787 (2003) 33–41.
R.L Santoni., J.S Tingle, M Nieves. Accelerated curing of silty sand using non-traditional additives. Transp. Res. Rec. 1936 (2005) 34–42.
A.R Zandieh, S.S. Yasrobi. Study of factors affecting the compressive strength of sandy soil stabilized with polymer. Geotechnical and Geological Engineering 28(2) (2010) 139–145.
A.B.A Brink. Engineering geology of Southern Africa. V. 1 South Africa: Building Publication. 1979.
M.Q.W. Jones, Thermal properties of stratified rocks from Witwatersrand gold mining areas. The J. of The South African Institute of Mining and Metallurgy. April (2003) 173–186.
W.E. Washburn. Note on a method of determining the distribution of pore sizes in a porous material, Proceedings of the National Academy of Sciences of the United States of America, 7(4) (1921) 115–116.
S. Horpibulsuk, S Rachan, Y Raksachon, Role of fly ash on strength and microstructure development in blended cement stabilized silty clay, Soils and Foundations 49(1) (2009) 85–98.
D. D. Penumadu, J. Dean. Compressibility effect in evaluating the pore-size distribution of kaolin clay using mercury intrusion porosimetry, Canadian Geotech. J. 37(2) (2000) 393–405.
A S, Naeini, B.A. Naderinia, E. Izadi, (2011). Unconfined compressive strength of clayey soils stabilized with waterborne polymer. KSCE J. Civ. Eng. 16(6) (2011) 943–949.
A Al Tabbaa, and J. A. Stegemann, Summary of Keynote Lectures in advances in stabilization and Solidifications. Proceeding of the International Conference on Stabilisation/Solidification Treatment and Remediation. April, Cambridge, UK, 2005 12–13.
D. N. Little, T. Scullion, P.V. Kota, J. Bhuiyan, Guidelines for Mixture Design and Thickness Design for Stabilized Bases and Subgrades, Report No. 1287-3F. Texas Transportation Institute, 1995.
Technical Recommendations for Highways (TRH 4). Cementitious Stabilizers in road Construction. Pretoria: South Africa, 1986.
H. Åhnberg, G. Holm, Stabilization of Some Swedish Organic Soils with Different Types of Binders. Proceeding of Dry Mix Methods for Deep Soil Stabilization, Stockholm: Balkema, 1999 101–108.