Curing Time Effect on Behavior of Cement Treated Marine Clay

Cement stabilization has been widely used for improving the strength and stiffness of soft clayey soils. Cement treated soil specimens used to investigate the stress-strain behaviour in the laboratory study are usually cured for 7 days. This paper examines the effects of curing time on the strength and stress strain behaviour of cement treated marine clay under triaxial loading condition. Laboratory-prepared cement treated Singapore marine clay with different mix proportion S-C-W (soil solid-cement solid-water) and curing time (7 days to 180 days) was investigated through conducting unconfined compressive strength test and triaxial test. The results show that the curing time has a significant effect on the unconfined compressive strength u q , isotropic compression behaviour and stress strain behaviour. Although the primary yield loci of the cement treated soil specimens with the same mix proportion expand with curing time, they are very narrowly banded and have nearly the same shape after being normalized by isotropic compression primary stress ' py p . The isotropic compression primary yield stress ' py p was shown to be linearly related to unconfined compressive strength u q for specimens with different curing time and mix proportion. The effect of curing time on the hardening behaviour will diminish with consolidation stress higher than isotropic compression primary yield stress but its damping rate is dependent on the cement content.




References:
[1] Tatsuoka, F. and Kobayashi, A., "Triaxial Strength Characteristics of
Cement-Teated Clay," in Proc. 8th ECSMFE, Helsinki, 1983, vol. 8, no.
1, pp. 421-426.
[2] Uddin, K., Balasubramaniam A.S., Bergado D.T., "Engineering
Behaviour of Cement-Treated Bangkok Soft Clay," Geotech. Eng., vol.
28, no.1, pp. 89-121, 1997.
[3] Chew, S. H., Kamruzzaman, A.H.M., and Lee, F.H., "Physico-Chemical
and Engineering Behaviour of Cement-Treated Clays," J. Geotech.
Geoenviron. Eng. ASCE, vol. 130, no. 7, pp. 696-706, 2004.
[4] Lee, F.H., Lee, Y., Chew, S. H., and Yong, K.Y., "Strength and Modulus
of Marine Clay-Cement Mixes," J. Geotech. Geoenviron. Eng., ASCE,
vol. 131, no.2, pp.178-186, 2005.
[5] Kezdi, A., Stabilized Earth Roads. Development in Geotechnical
Engineering, Elsevier Scientific, New York, 1979.
[6] Bergado, D.T., Anderson, L.R., Uiura, N. and Balasubramainam, A. S.,
Soft ground improvement in lowland and other environments. ASCE
press, New York, 1996.
[7] Kawasaki, T., Niina, A., Saitoh, S., Suzuki, Y. and Honjo, Y., "Deep
Mixing Method using Cement Hardening Agent," In Proc. 10th ICSMFE,
New York, 1981, vol. 3, pp.721-724.
[8] Saitoh, S., "Experimental Study of Engineering Properties of Cement
Improved Ground by the Deep Mixing Method", PhD dissertation, Nihon
University, Japan, 1988.
[9] Lorenzo, G.A. and Bergado. D.T., "Fundamental parameters of
cement-admixed clay - new approach," J. Geotech. Geoenviron. Eng.
ASCE, vol. 130, no.10, pp. 1042-1050, 2004.
[10] Kamruzzaman, A.H.M, "Physio-Chemical & Engineering Behaviour of
Cement Treated Singapore Marine Clay," Ph.D. dissertation, National
University of Singapore, Singapore, 2002.
[11] Tan, T.S., Phoon, K.K., Lee, F.H., Tanaka, H., Locat, J., and Chong, P.T.
"A Characterisation Study of Singapore Lower Marine Clay," in
Characterisation and Engineering Properties of Natural Soils, Tan et al.
(eds.). Swets & Zeitlinger, Lisse, 2003, pp. 429-454.
[12] Chin, K.G., Lee, F.H., and Dasari, G.R., "Effects of Curing Stress on
Mechanical Properties of Cement-Treated Soft Marine Clay," in Proc. Int.
Symp. on Engineering Practice and Performance of Soft Deposits, Osaka,
2004, pp. 217-222.
[13] Rotta, G.V., Consoli, N.C., Prietto, P.D.M., Coop, M.R. & Graham, J.,
"Isotropic Yielding in an Artificially Cemented Soil Cured under Stress,"
Geotechnique, vol. 53, no.5, pp.493-501, 2003.
[14] Barksdale, R.D. & Blight, G.E., "Compressibility and settlement of
residual soils. In Mechanics of residual soils," G.E. Blight Ed. Rotterdam:
A.A. Balkema, 1997, pp. 95-154.
[15] Smith P. R., Jardine R. J. and Hight D. W., "The yielding of Bothkennar
clay," Geotechnique, vol. 42, no. 2, pp.257-274, 1992.
[16] Cuccovillos T. and Coop M. R., "Yielding and pre-failure deformation of
structured sands", Geotechnique , vol.47, no.1, pp. 69-72, 1997.
[17] Huang, J.T., and Airey, D.W., "Properties of Artificially Cemented
Carbonate Sand," J. Geotech. Geoenviron. Eng. ASCE, vol. 124, no.6, pp.
492-499, 1998. Chin, K. G., "Constitutive behaviour of cement treated
marine clay," Ph.D. dissertation, National University of Singapore,
Singapore, 2006.