• Title/Summary/Keyword: Lime

Search Result 1,445, Processing Time 0.023 seconds

Geotechnical Engineering Characteristics and Consolidation Settlement Estimation of Waste Lime Landfill (폐석회 매립지반의 지반공학적 특성 및 압밀침하량산정)

  • Shin, Eun-Chul;Lee, Ae-Young
    • Journal of the Korean Geosynthetics Society
    • /
    • v.15 no.4
    • /
    • pp.1-8
    • /
    • 2016
  • The purpose of this study is to examine the consolidation characteristics of waste landfill from sodium carbonate production. The waste lime is a byproduct from the production of soda ash. The consolidation settlement of waste lime landfill was determined for waste lime specimen which obtained from the field boring. The consolidation tests are conducted for determination of the primary and secondary consolidation settlements. The waste lime is classified as an organic soil with high plasticity. As a result of an organic content test, the contents of organic matter in waste lime is much higher than that of normal clay. Finally, the total consolidation settlement of waste lime landfill is calculated by using a theoretical method and computer program for the given initial void ratio, compression index, and embankment height.

Specific Surface Area and Pore Structure Changes of Calcined Lime with Calcination and Sulfation Reaction (소성과 황화반응에 따른 생석회의 비표면적 및 기공구조 변화)

  • 강순국;정명규
    • Journal of environmental and Sanitary engineering
    • /
    • v.13 no.3
    • /
    • pp.19-29
    • /
    • 1998
  • The calcination reactivity of limestone and physical property changes of calcined lime were investigated with a temperature($720~1000^{\circ}C$ under atmospheric gas($N_2$, $CO_2$) conditions. The mechanisms of mass transport in a lime matrix were represented by the evaporation and condensation (${\gamma}=1.7$) at $1000^{\circ}C$ and the volume diffusion (${\gamma}=2.7$) at $800^{\circ}C$, which was obtained by the specific surface area of calcined lime with sintering conditions. Also, the effect of physical property on the reactivity of sulfation reaction was determined by the changes of pore size with $lime-SO_2$ reaction in this work. The initial sulfation rate of calcined lime increased with increasing temperature, whereas the capture capacity of $SO_2$ exhibited a maximum value at $900^{\circ}C$. The pore volume of sulfated lime was decreased with increasing sulfation time, but the major pores shifted to the distribution of larger size at a temperature of $850{\;}~{\;}1000^{\circ}C$. The mean pore size of sulfated lime based on pore volume decreased gradually at $1000^{\circ}C$; however, it increased with sulfation time up to 40 min and rapidly decreased thereafter.

  • PDF

Effect of Lime Amount and Application Time on Soil pH Change, Yield, and Quality of Leaf Tobacco (석회시용량과 시용시기가 경작지 토양산도 변화와 잎담배 수량 및 품질에 미치는 영향)

  • 정훈채;김용연;황건중
    • Journal of the Korean Society of Tobacco Science
    • /
    • v.22 no.1
    • /
    • pp.61-70
    • /
    • 2000
  • This study was carried out to improve the tobacco field condition and to determine the effect of lime amount and application time on soil pH, yield, and quality of leaf tobacco. Lime was applied to the tobacco field by determined amounts according to different pH level. The changes of soil pH, growth of tobacco, yield, and quality of KF109 and Br21 tobacco were surveyed by time lapse. The target pH value in tobacco field soil can be reached at 6 weeks after lime application, and then the soil pH was lowered slightly after that time. The lime amount needed to reach target pH was decreased 40 % in the same tobacco field after 1 year. Though the initial growth rate of flue-cured tobacco in the field of pH 7.0 was lower than that of conventional tobacco field, the field of pH 7.0 showed the highest yield after the maximum growth stage. The quality of cured leaf tobacco in the field of pH 7.0 applied lime at spring season was slightly lowered compared with that in conventional. This results indicated that the best pH condition in tobacco field for the best tobacco growth was 6.5 and the proper time of lime application was fall season of previous year by application of the whole quantity.

  • PDF

Improvement Effects of Soft Clay Soils Using Quick Lime Piles (생석회 말뚝을 이용한 연약점토지반의 개량효과)

  • Kim, Younghun;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
    • /
    • v.11 no.5
    • /
    • pp.45-51
    • /
    • 2010
  • This study is to evaluate an application of technology to the soft ground stability using quick lime pile in the field. We investigated properties of Korean quick lime by conducting loading test and theoretical consideration about a principle and property of soft ground improvement by quicklime. According to the test results, it was estimated that quick lime pile method has dehydration effect by absorption of quick lime, consolidation effect by swelling of pile, increasing bearing by strength of pile itself and decreasing sinking effect, etc. A material property of quick lime is favorable for construction and considerable strength. In the case of higher strength is required, using cement as additive would increase material strength.

Study of geotechnical properties of a gypsiferous soil treated with lime and silica fume

  • Moayyeri, Neda;Oulapour, Masoud;Haghighi, Ali
    • 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.

The Transmembrane Adaptor Protein LIME Is Essential for Chemokine-Mediated Migration of Effector T Cells to Inflammatiory Sites

  • Park, Inyoung;Son, Myongsun;Ahn, Eunseon;Kim, Young-Woong;Kong, Young-Yun;Yun, Yungdae
    • Molecules and Cells
    • /
    • v.43 no.11
    • /
    • pp.921-934
    • /
    • 2020
  • Lck-interacting transmembrane adaptor 1 (LIME) has been previously identified as a raft-associated transmembrane protein expressed predominantly in T and B lymphocytes. Although LIME is shown to transduce the immunoreceptor signaling and immunological synapse formation via its tyrosine phosphorylation by Lck, a Src-family kinase, the in vivo function of LIME has remained elusive in the previous studies. Here we report that LIME is preferentially expressed in effector T cells and mediates chemokine-mediated T cell migration. Interestingly, in LIME-/- mice, while T cell receptor stimulation-dependent proliferation, differentiation to effector T cells, cytotoxic T lymphocyte (CTL) function and regulatory T lymphocyte (Treg) function were normal, only T cell-mediated inflammatory response was significantly defective. The reduced inflammation was accompanied by the impaired infiltration of leukocytes and T cells to the inflammatory sites of LIME-/- mice. More specifically, the absence of LIME in effector T cells resulted in the reduced migration and defective morphological polarization in response to inflammatory chemokines such as CCL5 and CXCL10. Consistently, LIME-/- effector T cells were found to be defective in chemokine-mediated activation of Rac1 and Rap1, and dysregulated phosphorylation of Pyk2 and Cas. Taken together, the present findings show that LIME is a critical regulator of inflammatory chemokine-mediated signaling and the subsequent migration of effector T cells to inflammatory sites.

The effect of hydrated lime on the petrography and strength characteristics of Illite clay

  • Rastegarnia, Ahmad;Alizadeh, Seyed Mehdi Seyed;Esfahani, Mohammad Khaleghi;Amini, Omid;Utyuzh, Anatolij Sergeevich
    • Geomechanics and Engineering
    • /
    • v.22 no.2
    • /
    • pp.143-152
    • /
    • 2020
  • In this research, soil samples of the Kerman sedimentary basin, Iran, were investigated through laboratory tests such as petrography (Scanning Electron Microscopy (SEM), X-Ray Fluorescence Spectroscopy (XRF) and X-Ray Diffraction (XRD)), physical and mechanical characteristics tests. The soil in this area is dominantly CL. The petrography results showed that the dominant clay mineral is Illite. This soil has made some problems in the earth dams due to the low shear strength. In this study, a set of samples were prepared by adding different amounts of lime. Next, the petrography and strength tests at the optimum moisture content were performed. The results of SEM analysis showed substantial changes in the soil structure after the addition of lime. The primary structure was porous and granular that was changed to a uniform and solid after the lime was added. According to XRD results, dominant mineral in none stabilized soil and stabilized soil are Illite and calcite, respectively. The pozzolanic reaction resulted in the reduction of clay minerals in the stabilized samples and calcite was known as the soil hardener material that led to an increase in soil strength. An increase in the hydrated lime leads to a decrease in their maximum dry unit weight and an increase in their optimum moisture content. Furthermore, increasing the hydrated lime content enhanced the Unconfined Compressive Strength (UCS) and soil's optimum moisture. An increase in the strength is significantly affected by the curing time and hydrated lime contents, as the maximum compressive strength is achieved at 7% hydrated lime. Moreover, the maximum increase in the California Bearing Ratio (CBR) achieved in clay soils mixed with 8% hydrated lime.

Geotechnical Characteristics and Field application of Soil Mixed with Waste Lime (부산석회 혼합토의 지반공학적 특성 및 현장 적용 사례)

  • 정하익;홍승서;김상근;홍성완;유홍기;임병익
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2003.03a
    • /
    • pp.217-222
    • /
    • 2003
  • This study was carried out to investigate the geotechnical characteristics and field application of soil mixed with waste lime. Waste lime used in this study is producted as a by-product in the manufacturing process of making Na$_2$CO$_3$from local chemical factory in Incheon. Currently about 320 milton tons of waste lime are accumulated and annually 100,000 tons are producted. In this study, feasible use of waste lime mixed with granited whathered soil, clay, crushed rock was invesigated through laboratory tests including specific gravity test, sieve analysis, hydrometer analysis, compaction test, CBR test. Field investigations were conducted on the road construction site in Incheon.

  • PDF

Strength and Permeability of Sand-Bentonite-Lime mixtures (모래-벤토나이트-생석회 혼합물의 강도 및 투수특성)

  • 구정민;권무남;김현기
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.43 no.2
    • /
    • pp.122-131
    • /
    • 2001
  • When mixed with lime, sand-bentonite mixture is characterized by considerable hydraulic properties similar to natural pozzolans and may therefore be increased in the strength of sand-bentonite mixture. The present study reports that results obtained in a series of laboratory tests carried out using particular mixing ratio of lime-sand-bentonite with the aim of investigating physical characteristics, permeability and strength. The results were compared and analyzed according to hydration time and lime content. Test results showed that increasing of strength and decreasing of permeability by proper lime content. Curing for longer periods increased unconfined compressive strength of mixture. Based on results of the falling head permeability test, mixtures of lime content 3%, 6% and 9% were satisfied in using as liner after 8-day curing periods.

  • PDF

Bearing Capacity and Environmental Assessment on Ground with By-product Lime (부산석회 재활용 부지에 대한 지지력 및 환경영향 평가에 관한 연구)

  • Chung, Ha-Ik;Hong, Seung-Seo;Lee, Yong-Soo
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2004.03b
    • /
    • pp.897-903
    • /
    • 2004
  • Waste lime used in this study is producted as a by-product in the manufacturing process of making $Na_2CO_3$ from local chemical factory in Incheon. Currently about 320 millon tons of waste lime are accumulated and annually 100,000 tons are producted. Reuse of waste lime mixed with soil for banking and backfill materia in civil works was analysed in this study. This study was Carried out to investigate the geotechnical and environmental characteristics on field application. Field investigations were conducted on the road construction site in Incheon. This study presents the results of the engineering characteristics in field test and the leaching characteristic of waste lime in laboratory column tests. Countermeasure for reduction of environmental effects was suggested from the test results.

  • PDF