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Fine-grained soils that expand when in contact with water can be a major issue in some geotechnical situations, but the soil can be stabilized through chemical means by hydrated lime incorporation. However, there is not yet any rational dosage methodology that combines the effects of both lime content and porosity of the treated soil specimen to predict its behavior regarding swelling. Thus, the present research intends to assess the one-dimensional swelling response of an expansive fine-grained soil stabilized with lime. For this purpose, compacted soil–lime blends were molded with three distinct amounts of lime (2%, 4%, and 6%), compacted to three different dry unit weights (14, 15, and 16 kN/m3) and tested after 3 h of curing. The results show that lime content, porosity, and their interaction are statistically significant in altering the swelling behavior of the compacted blends. Moreover, both can be combined through the adjusted porosity/lime index and related to the one-dimensional swelling. As a result, a single unique relationship could be established between the swelling and the proposed index with a coefficient of correlation (R2) of 96%. This approach was also successfully employed in other fine-grained soils treated with lime as validation. [ABSTRACT FROM AUTHOR]

Given the schedule pressure of lime-stabilized soil construction, many agencies specify the use of elevated temperature (e.g., 41°C), shorter duration (e.g., 5-7 days) accelerated specimen curing for unconfined compressive strength () testing and acceptance as a proxy for of specimens normally cured under 28-day 23°C conditions. Moreover, lime and highway transportation industry associations prescribe a unique accelerated curing regime for all lime-stabilized soils (7-day, 41°C). This paper presents the results from a laboratory investigation of stress-strain-strength development of four lime-stabilized soils under 2-8 day 41°C accelerated curing and the 0-28 day 23°C normal curing regime. Specimens cured at 41°C reached values equivalent to 28-day 23°C after 1.8-5.9 days. Accordingly, 7-day 41°C curing overestimates 28-day normal cure by 13-260%. When combined with a detailed analysis of data available in the literature, the results illustrate that the prescription of a unique equivalent accelerated curing regime is oversimplified and can lead to significant overestimation of design . [ABSTRACT FROM AUTHOR]

Lime treatment is an attractive technique for soil improvement in the construction of rail tracks and pavement layers, in slope protection of earth dams, and as a support layer for shallow foundations. However, there are no dosage methodologies based on rational criteria as in the case of soil-cement technology, where the voids/cement ratio is shown to be a key parameter for the estimation of both strength and stiffness. The present study, therefore, was aimed at quantifying the influence of the amount of lime, porosity, and voids/lime ratio on the initial shear modulus (G0) and unconfined compressive strength (qu) of a lime-treated clayey sandy soil. From the results of unconfined compression tests and bender elements measurements, it was shown, for the soil-lime mixtures investigated, that the voids/lime ratio is an appropriate parameter to assess both initial stiffness and unconfined compressive strength. Also, a unique G0/qu versus voids/lime ratio relationship was established linking the soil-lime mixture initial stiffness and compressive strength. [ABSTRACT FROM AUTHOR]

Laboratory tests have been carried out in order to evaluate the improvement in engineering properties relevant to highway design and construction obtained when clayey subgrade soils are stabilized with lime or fly ash. The experimental program included California bearing ratio (CBR) tests to evaluate the bearing strength of stabilized soils used as working platforms during highway construction. The admixture of lime or fly ash caused an increase in the plasticity limit, while both the liquid limit and the plasticity index of the soils have been reduced. Substantial increases in the California bearing ratio value, higher than those of the soil-fly ash mixtures, have been obtained when the soil samples were mixed with lime. The swelling after a 4-day soaking period has been reduced with the addition of both additive materials. The increase in optimum moisture content acts subsidiarily to the increased CBR value, particularly at high lime or fly ash percentages. An analogous effect has been found for the maximum dry density reduction. [ABSTRACT FROM AUTHOR]