Suelo cemento

Key Parameters for the Strength Control of Lime
Stabilized Soils
Nilo Cesar Consoli, Ph.D.1; Luizmar da Silva Lopes Jr.2; and Karla Salvagni Heineck3
Abstract: The addition of lime is an attractive technique when the project requires improvement of the local soil. The treatment of soils
with lime finds an application, for instance, in the construction of pavement base layers, in slopeprotection of earth dams, and as a support
layer for shallow foundations. However, there are no dosage methodologies based on rational criteria as exist in the case of the concrete,
where the water/cement ratio plays a fundamental role in the assessment of the target strength, and in the case of soil–cement technology,
where the voids/cement ratio is shown to be a good parameter for the estimation ofunconfined compression strength. This study,
therefore, aims to quantify the influence of the amount of lime, the porosity, and the moisture content on the strength of a lime-treated
sandy lean clay soil, as well as to evaluate the use of a water/lime ratio and a voids/lime ratio to assess its unconfined compression
strength. A number of unconfined compression tests and measurements of matricsuction were carried out. The results show that the
unconfined compression strength increased linearly with the increase in the lime content as well as with the reduction in porosity of the
compacted mixture. The change in moisture content has not presented an obvious effect on the unconfined compression strength of
mixtures compacted at the same dry density. It was shown that, for the soil–limemixture in an unsaturated state which is usual for
compacted fills , the water/lime ratio is not a good parameter for the assessment of unconfined compression strength. In contrast, the
voids/lime ratio, defined as the ratio between the porosity of the compacted mixture and the volumetric lime content, is demonstrated to
be the most appropriate parameter to assess the unconfined compression strength ofthe soi-lime mixture studied.
DOI: 10.1061/ ASCE 0899-1561 2009 21:5 210
CE Database subject headings: Lime; Compacted soils; Compression tests; Soil stabilization.

Introduction
The improved characteristics of compacted soils resulting from
lime utilization may be very important to some geotechnical engineering applications such as canal lining, pavement structures,
and engineered fillsTransportation Research Board 1987; Carraro 1997; Consoli et al. 2001 . Several methodologies were established in the last 50 years Hilt and Davidson 1960; Eades and
Grim 1966; Rogers et al. 1997 in order to determine the needed
amounts of lime required for modification of soil characteristics
and introduce adequate strength and durability to the use. Such
methodologies intend to establish athreshold value, supposed to
chemically satisfy the soil demand for lime, which has often been
suggested as the starting content to adopt for construction expediency purposes. In spite of the numerous applications, there are
no dosage methodologies for the assessment of a target strength,
based on rational criteria as in the case of the concrete technol1

Associate Professor, Dept. of CivilEngineering, Federal Univ. of Rio
Grande do Sul, Av. Osvaldo Aranha, 99, 3. Andar 90035-190 Porto Alegre
Rio Grande do Sul, Brazil corresponding author . E-mail: consoli@
ufrgs.br
2
Ph.D. Student, Federal Univ. of Rio Grande do Sul, Rio Grande do
Sul, Brazil. E-mail: luizmar junior@yahoo.com.br
3
Adjunct Professor, Federal Univ. of Rio Grande do Sul, Rio Grande
do Sul, Brazil. E-mail:karla@ppgec.ufrgs.br
Note. Associate Editor: Anand J. Puppala. Discussion open until
October 1, 2009. Separate discussions must be submitted for individual
papers. The manuscript for this paper was submitted for review and possible publication on July 31, 2007; approved on November 25, 2008. This
paper is part of the Journal of Materials in Civil Engineering, Vol. 21,
No. 5, May 1, 2009. ©ASCE, ISSN...