• Geomechanics and Engineering
• /
• v.7 no.3
• /
• pp.247-261
• /
• 2014

Analytical and numerical modeling of soft or problematic soils stabilized with lime and cement require a number of soil parameters which are usually obtained from expensive and time-consuming laboratory experiments. The high shear strength of lime and cement stabilized soils make it extremely difficult to obtain high quality laboratory data in some cases. In this study, an alternative method is proposed, which uses the unconfined compressive strength and estimating functions available in literature to evaluate the shear strength parameters of the treated materials. The estimated properties were applied in finite element model to determine which estimating function is more appropriate for lime and cement treated granular soils. The results show that at the mid-range strength of the stabilized soils, most of applied functions have a good compatibility with laboratory conditions. However, application of some functions at lower or higher strengths would lead to underestimation or overestimation of the unconfined compressive strength.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2000.11a
• /
• pp.55-62
• /
• 2000

In this paper, a laboratory investigation was carried out to estimate the strength improvement of quicklime mixture with fly ash and rice husk ash for the effective use of surplus soils, and the shear strength with curing time was estimated at lime 10 percent with the change of fly ash and rice husk ash content. The effect of strength improvement has been established through the change of fly ash and rice husk ash content from the samples taken at Samsan region, Ulsan. The test results indicated that the presence of lime with fly ash and rice husk ash encouraged the stabilization efficiency of lime with fly ash and rice husk ash, and increased shear strength. Furthermore, it is necessary for inquiring into the relationship between the characteristics of strength and the chemical components.

• Geomechanics and Engineering
• /
• v.17 no.2
• /
• pp.195-206
• /
• 2019

The gypsiferous soils are significantly sensitive to moisture and the water has a severe destructive effect on them. Therefore, the effect of lime and silica fume addition on their mechanical properties, when subjected to water, is investigated. Gypsiferous soil specimens were mixed with 1, 2 and 3% lime and 1, 3, 5 and 7% silica fume, in terms of the dry weight of soil. The specimens were mixed at optimum moisture content and cured for 24 hours, 7 and 28 days. 86 specimens in the sizes of unconfined compression strength test mold were prepared to perform unconfined compressive strength and durability tests. The results proved that adding even 1% of each of these additives can lead to a 15 times increase in unconfined compressive strength, compared with untreated specimen, and this increases as the curing time is prolonged. Also, after soaking, the compressive strength of the specimens stabilized with 2 and 3% lime plus different percentages of silica fume was considerably higher than before soaking. The durability of the treated specimens increased significantly after soaking. Direct shear tests showed that lime treatment is more efficient than silica fume treatment. Moreover, it is concluded that the initial tangent modulus and the strain at failure increased as the normal stress of the test was increased. Also, the higher lime contents, up to certain limits, increase the shear strength. Therefore, simultaneous use of lime and silica fume is recommended to improve the geotechnical properties of gypsiferous soils.

• Geomechanics and Engineering
• /
• v.15 no.4
• /
• pp.1005-1016
• /
• 2018

This paper presents an investigation on the properties of two types of cement kiln dust (CKD)-stabilized dredged sediments, silt and clay with a comparison to hydrated lime stabilization. Unconfined compressive strength (UCS) and California bearing ratio (CBR) tests were conducted to examine the optimal stabilizer content and classify the type of highway material. A strength development model of treated dredged sediments was performed. The influences of various stabilizer types and sediment types on UCS were interpreted with the aid of microstructural observations, including X-ray diffraction and scanning electron microscopy analysis. The results of the tests revealed that 6% of lime by dry weight can be suggested as optimal content for the improvement of clay and silt as selected materials. For CKD-stabilized sediment as soil cement subbase material, the use of 8% CKD was suggested as optimal content for clay, whereas 6% CKD was recommended for silt; the overall CBR value agreed with the UCS test. The reaction products calcium silicate hydrate and ettringite are the controlling mechanisms for the mechanical performance of CKD-stabilized sediments, whereas calcium aluminate hydrate is the control for lime-stabilized sediments. These results will contribute to the use of CKD as a sustainable and novel stabilizer for lime in highway material applications.

• Proceedings of the Korean Geotechical Society Conference
• /
• 1999.10a
• /
• pp.227-232
• /
• 1999

In this paper, a laboratory investigation was carried out to estimate the strength improvement of quicklime mixture for the effective use of surplus soils, and the shear strength with curing time was estimated at the content of lime. The effect of strength improvement has been established through the change of lime content with chlorides and sulfates from the samples taken at Samsan region, Ulsan. The test results indicated that the presence of calcium sulphate encouraged the efficiency of lime stabilization, and increased shear strength. Furthermore, it is necessary for inquiring into the relationship between the characteristics of strength and the chemical components.

• Journal of the Korean GEO-environmental Society
• /
• v.23 no.1
• /
• pp.5-13
• /
• 2022

In tropical regions, lateritic soil is frequently used in road embankment. However, it is one of the sources of road failure owing to its low strength. Generally, cement and lime are used as stabilizers for lateritic soil, but they are not environmentally friendly. Some studies try to use eggshells, for they are food waste and share the same chemical composition as lime. Previous researchs have shown that eggshell powder could enhance the strength of lateritic soil. This research investigated the effect of particle size of the eggshell powder and the effect of the protein-membrane presence in the eggshell on stabilizing capacity of soil. Through laboratory tests, unconfined compressive strength was examined for various particle sizes. The particle size of eggshell powder ranging between 150 ㎛ and 88 ㎛ was appropriate size that made an excellent stabilizer at 3% concentration. On the other hand, the protein-membrane reduced the stabilizing ability of the eggshell powder when the content of eggshell powder is less than 4% in soil. Numerical analysis of road embankment was performed based on the results obtained in the laboratory tests. It is shown that the eggshell powder has improved the stability of the sub-base of the road embankment.

• Journal of the Korean Geotechnical Society
• /
• v.27 no.5
• /
• pp.5-15
• /
• 2011

Recent increase of large scale construction near costal area has also increased the application of soft ground treatment. As a result, solidification with cement and lime which increases stability and durability of soils, is frequently used for surface layer stabilization in soft ground site. While stabilization of very soft clay with high plasticity and compressibility has widely been studied, studies on silty clay with low plasticity and compressibility are relatively rare. In this study, after stabilizing low plasticity silty clay of Songdo area with cement and lime under various water contents, mixing ratio, and curing time, uniaxial compression test and plate load test were performed. Strength properties from both tests were considerably consistent. And trackability of construction equipment on the treated surface layer of dredged land was estimated. Finally, optimum mixing condition for Songdo silty clay was proposed.

• Korean Journal of Environmental Agriculture
• /
• v.33 no.1
• /
• pp.1-8
• /
• 2014

BACKGROUND: Recent studies using many amendments for heavy metal stabilization in soil were conducted in order to find out new materials. But, the studies accounting for the use of appropriate amendments considering soil pH remain incomplete. The aim of this study was to investigate the effects of initial soil pH on the efficiency of various amendments. METHODS AND RESULTS: Acid soil and alkali soil contaminated with heavy metals were collected from the agricultural soils affected by the abandoned mine sites nearby. Three different types of amendments were selected with hypothesis being different in stabilization mechanisms; organic matter, lime stone and iron, and added with different combination. For determining the changes in the extractable heavy metals, water soluble, Mehlich-3, Toxicity Characteristic Leaching Procedure, Simple Bioavailability Extraction Test method were applied as chemical assessments for metal stabilization. For biological assessments, soil respiration and root elongation of bok choy (Brassica campestris ssp. Chinensis Jusl.) were determined. CONCLUSION: It was revealed that lime stone reduced heavy metal mobility in acid soil by increasing soil pH and iron was good at stabilizing heavy metals by supplying adsorption sites in alkali soil. Organic matter was a good source in terms of supplying nutrients, but it was concerning when accounting for increasing metal availability.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.1
• /
• pp.545-551
• /
• 2011

Recently, demands for generating high quality tap waters are increasing with high concern of water pollution and corrosion of water pipelines. For the reasons, developing water quality stabilization technique in water purification system is sought rather than replacing to a new pipelines. In this study, high-purity liquid lime($Ca(OH)_2$) was introduced for a water quality stabilization technique in water purification process and simulated water distribution system of pilot-scale size was applied to evaluate anti-corrosion control effect. The effect of anti-corrosion control was calculated in terms of LSI(Langelier Saturation Index) In conclusion, the result of pilot plant showed improvement of corrosiveness by liquid lime($Ca(OH)_2$) with reduction of released iron(Fe). Application of anti-corrosion control technique to the mild steel coupon and the copper coupon were effective by indicating 35.4, 44.5% of improvements. Besides, sample pipes which were treated with liquid lime had formated more thicker layer of corrosion product inside of pipes. As a result, the process of injecting water stabilizer can greatly contribute to the high quality of tap water.

• Geomechanics and Engineering
• /
• v.8 no.1
• /
• pp.113-132
• /
• 2015

In this study, lime (L), silica fume (SF), and lime-silica fume (L-SF) mix have been used for stabilizing and considering their effects on the soft clay soil. The improvement technique adopted in this study includes improving the behaviour, of a square footing over soft clay through grouting the clay with a slurry of lime-silica fume before and after installation of the footing. A grey-colored densified silica fume is used. Three percentages are used for lime (2%, 4% and 6%) and three percentages are used for silica fume (2.5%, 5%, 10%) and the optimum percentage of silica fume is mixed with the percentages of lime. Several tests are made to investigate the soil behaviour after adding the limeand silica fume. For grouting the soft clay underneath and around the footing, a 60 ml needle was used as a liquid tank of the lime-silica fume mix. Slurried silica fume typically contains 40 to 60% silica fume by mass. Four categories were studied to stabilize soft clay before and after footing construction and for each category, the effectiveness of grouting was investigated; the effect of injection hole spacing and depth of grout was investigated too. It was found that when the soft clay underneath or around a footing is injected by a slurry of lime-silica fume, an increase in the bearing capacity in the range of (6.58-88)% is obtained. The footing bearing capacity increases with increase of depth of grouting holes around the footing area due to increase in L-SF grout. The grouting near the footing to a distance of 0.5 B is more effective than grouting at a distance of 1.0 B due to shape of shear failure of soft clay around the footing.