• Title/Summary/Keyword: Stabilizer contents

Search Result 44, Processing Time 0.023 seconds

A Study on the mix design for the Soilcrete by Using FGC Soil Stabilizer (FGC계 고화재를 이용한 Soilcrete 배합설계에 관한 연구)

  • 천병식;고갑수;김진춘;하상욱
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 1999.10a
    • /
    • pp.293-300
    • /
    • 1999
  • Soilcrete has been the traditional material for the paving and soft ground improvement techniques. But because the durability is not excellent and the quality is not homogeneous, it has not been used for the various purposes up to date. And because the quality of soilcrete is apt to be changed by the content of water and soil stabilizer, and the kind of soil and soil stabilizer, it is not free of cares. But with the increase of naturally oriented needs for the light traffic road such as pedestrian roads of the garden, golf courses and sidewalks, the cases of soilcrete paving has been increased recently. This study aims at making the reference table of the mix design in accordance with the required design specifications for the soilcrete admixtures by the FGC soil stabilizer by using the statistical experiment method. The treated soil is the clay which are widely spreaded in Korea. As the results of this study we can derive the effective reference mix design table for the clay soil treated by the FGC soil stabilizer in accordance with the compressive strength of 50∼200kg/$\textrm{cm}^2$ soilcrete with respect to the contents of water, soil stabilizer and fine sand.

  • PDF

Cavitation-Erosion Characteristics of the Stainless Steel with Adding Ti Stabilizer Element in Sea Water (안정화 원소 Ti 첨가에 따른 스테인리스강의 해수 내 캐비테이션-침식 특성)

  • Choi, Yong-Won;Yang, Ye-Jin;Kim, Seong-Jong
    • Journal of the Korean institute of surface engineering
    • /
    • v.49 no.4
    • /
    • pp.344-348
    • /
    • 2016
  • Stainless steel is widely applied in many industrial fields due to its excellent anti-corrosion and durability characteristics. However, stainless steel is very vulnerable to cavitation attack caused by high speed flow of fluid in the chloride environments such as marine environment. These conditions promote intergranular corrosion and cavitation-erosion, leading to degradation of the structural integrity and service life. In order to prevent these problems, the stabilized stainless steel is applied to the offshore and shipbuilding industries. In this study, Ti was added to 19%Cr-9%Ni as the stabilizer element with different concentrations (0.26%, 0.71%), and their durabilities were evaluated with cavitation-erosion experiment by a modified ASTM G32 method. The microstructural change was observed with the stabilizer element contents. The result of the observation indicated that the amount of carbide precipitation was decreased and its size became finer with increasing Ti content. In the cavitation-erosion experiment, both weight loss and surface damage depth represented an inverse proportional relationship with the amount of Ti element. Consequently, the stainless steel containing 0.71% of Ti had excellent durability characteristics.

Contents of $\beta$-Glucan in Various Cereals and Its Functional Properties

  • Whang, Key
    • Preventive Nutrition and Food Science
    • /
    • v.3 no.4
    • /
    • pp.382-386
    • /
    • 1998
  • A soluble dietary fiber, $\beta$-glucan, contained in oat and barley has nutritional benefits such as hypocholesterolemic effects and influences blood glucose regulation. The contents of $\beta$-glucan in both cereals range from 3 to 7% with the exception of a certain barley genotype which contains up to 16% $\beta$-glucan. $\beta$-Glucan is distributed mainly in the cell walls of endosperm and the distal (bran) portion of kernel. Various procedures have been developed for increasing the extraction yield of $\beta$-glucan. Oat gum prepared with weak alkali extractionand alcohol proecipitation following protein removal usually contains 80% $\beta$-glucan.The most commonly used method for $\beta$-glucan quantitiation is an enzymatic procedure combining lichenase plus $\beta$-glucosidase followed by measuring the amount of glucos released by glucose oxidase-peroxidase treatment. The increase in foam-and emulsion-stabilizing capacity of $\beta$-glucan is due to the increase in viscosity of the aqueous phase. Therefore, $\beta$-glucan shows great potentials as a thickener and a stabilizer.

  • PDF

The Strength Characteristics of Deep Mixing Ground According to Increasing Water Contents (함수비 증가에 따른 심층혼합지반의 강도특성)

  • Park, Choon-Sik;Choi, Jun-Sam
    • Journal of the Korean Geotechnical Society
    • /
    • v.35 no.3
    • /
    • pp.25-35
    • /
    • 2019
  • A laboratory test on uniaxial compressive strength was carried out by making 640 specimens in total, which were divided into two groups by their curing time of 7 and 28 days for 3 water content conditions of a water content at 100% saturation level and 10% and 20% increased water content from the state with clay, sand and gravel mixed grounds of 20 ground conditions of 4 types of stabilizer mixing conditions which were 8%, 10%, 12%, 14%, to understand laboratory strength characteristics for strength design of deep mixing ground. In case of clayey grounds, although the strength increased depending on the increase of stabilizer content, it showed to be analogous regardless of the curing time. And the impact on the strength development of deep mixing specimen according to water content was considered to be comparatively little compared to other grounds. For sandy grounds, the strength increment amount clearly showed to increase as stabilizer content increased, and also the increase of water content was determined to be decreasing the strength increment effect. For gravel mixed grounds, at 14% or over of stabilizer content, the effect on strength development was big making a large increase in strength, but compared to sandy grounds, the strength ratio depending on the curing time showed to be small.

A Study on Surface Mixing Method by Chemical Stabilizer (화학약액에 의한 표층혼합공법에 관한 연구)

  • 진병익;유재일
    • Geotechnical Engineering
    • /
    • v.1 no.2
    • /
    • pp.55-66
    • /
    • 1985
  • This paper is studied about the character of mixed soil which is applied lime and water-glass The effectiveness of mining such as cut-off effect and shear strength increasement of the chemically treated soils are investigated. For the main purpose of this study is to develope economical and practical method in chemical mixing method. The principal contents are described as follow. (1) Lime and water-glass series are used as chemical stabilizer and secondary additives in this experiment. (2) This study was analized and compared with engineering properties by the quantity of additives and by the character of chemical stabilizer. (3) And the effects of improvement in those treated soils are investigated as below; the increasement of shear strength, cut.off effect and consolidation character.

  • PDF

Effect of Iron Content on Microstructure and Mechanical Properties of Ti-Mo-Fe P/M Alloys (Fe 함량에 따른 Ti-Mo-Fe 분말합금의 미세조직 및 기계적 특성 변화)

  • Hwang, HyoWoon;Lee, YongJae;Park, JiHwan;Lee, Dong-Geun
    • Journal of Powder Materials
    • /
    • v.29 no.4
    • /
    • pp.325-331
    • /
    • 2022
  • Beta-titanium alloys are used in many industries due to their increased elongation resulting from their BCC structure and low modulus of elasticity. However, there are many limitations to their use due to the high cost of beta-stabilizer elements. In this study, biocompatible Ti-Mo-Fe beta titanium alloys are designed by replacing costly beta-stabilizer elements (e.g., Nb, Zr, or Ta) with inexpensive Mo and Fe elements. Additionally, Ti-Mo-Fe alloys designed with different Fe contents are fabricated using powder metallurgy. Fe is a strong, biocompatible beta-stabilizer element and a low-cost alloying element. The mechanical properties of the Ti-Mo-Fe metastable beta titanium alloys are analyzed in relation to the microstructural changes. When the Fe content increases, the tensile strength and elongation decrease due to brittle fracture despite a decreasing pore fraction. It is confirmed that the hardness and tensile strength of Ti-5Mo-2Fe P/M improve to more than 360 Hv and 900 MPa, respectively.

Strength and Deformation Characteristics on Stabilized Pavement Geomaterials (II) : Numerical Analysis (안정처리된 도로하부 지반재료의 강도 및 변형특성 (II) : 수치해석)

  • Park, Seong-Wan;Ji, Jong-Keun
    • International Journal of Highway Engineering
    • /
    • v.11 no.2
    • /
    • pp.205-216
    • /
    • 2009
  • As a subsequent study, this paper presents a comparative evaluation of structural responses in asphalt pavements with stabilized foundations. The approach based on a finite element analysis which incorporates non-linear behaviors of pavement geomaterials is used to estimate each performance indicator under standard single axle loading condition. In addition, results from laboratory tests are used to provide physical and mechanical properties of stabilized geomaterials for analyzing various pavement structures. Changes in pavement responses with varying layer thickness and stabilizer contents were investigated. It is found that the effect of layer thickness and stabilizer content is a critical factor in structural response of stabilized pavements. Moreover, a design criterion is proposed for selecting minimum contents of stabilizer of coarse-grained geomaterials based on a result of unconfined compressive strength and proper layer thickness of foundations.

  • PDF

Accelerated Aging Characteristics of a Double Base Propellant (복기추진제의 가속 노화 특성 연구)

  • Go, Cheongah;Park, Youngchul;Seo, Taeseok;Moon, Youngtaek;Kim, Junhyung
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.23 no.4
    • /
    • pp.61-69
    • /
    • 2019
  • Accelerated aging test for the double base propellant was carried out at three different temperatures (60, 70, and $75^{\circ}C$) for over a year. To evaluate the aging characteristics of the double base propellant, the stabilizer contents and thermal decomposition kinetics were analyzed by using high performance liquid chromatography (HPLC) and AKTS-Thermokinetics software. As a result, stabilizer contents in the double base propellant gradually decreased according to the aging temperature and aging duration. The consumption rate of 2-NDPA in the accelerated aged propellants showed that it was two times faster at $75^{\circ}C$ in compared with ther rate at $70^{\circ}C$. These experimental values were simulated by the SB kinetic model, and it was shown that the two-step model with constant reaction orders n1=1 and n2=0 best describes the process of the stabilizer depletion for the double base propellant.

An Experimental Study on the Elastic Modulus of Deep Mixing Ground Specimen (심층혼합 시료의 탄성계수에 관한 실험적 연구)

  • Park, Choon-Sik;Park, Hwan-Ki
    • Journal of the Korean Geotechnical Society
    • /
    • v.34 no.10
    • /
    • pp.39-49
    • /
    • 2018
  • In this study, aimed at determining the elastic modulus of deep mixed samples, 320 test specimens were developed by mixing 8%, 10%, 12%, and 14% of stabilizer mixture in the granular conditions of clay, sand and gravel. Uniaxial compression tests were carried out using these specimens, and the uniaxial compression strength and strain were analyzed to determine the secant elastic modulus and tangent elastic modulus. Laboratory test results showed that the uniaxial compression strength of all deep mixed samples increased with increasing curing time and stabilizer mixing ratio, and that the secant elastic modulus and the tangen elastic modulus also increased. The increase of the elastic modulus according to the curing period turned out greater in the tangent elastic modulus than in the secant elastic modulus. In order to measure elastic modulus with changes in stabilizer mixing ratio, the correlation coefficient between the elastic modulus for stabilizer mixing ratio of 8% and that of 10%, 12% and 14% was calculated respectively by the specimen condition. The elastic modulus tended to increase as the grain size in a deep mixed specimen increased. The distribution of grain size that had the greatest effect appeared when the composition ratio of sand was high. On the other hand, the increase in the elastic modulus was larger in the sand specimens than in the clay and gravel specimens. Based on these results, it is suggested that a pertinent soil parameter of the deep mixed ground in the field may be obtained by the particle size distribution and the mixing ratio of stabilizer of the deep mixed soil.

Anthocyanin-Contents and Pigment Stability of Black Soybean by Different Extract Condition and Stabilizer (추출조건과 첨가물에 따른 검정콩의 안토시아닌 함량과 색소 안정성)

  • Lee, Hye-Jeong;Choi, Eun-Young;Sim, Young-Ja;Kim, Ok-Sun;Yoo, Ho-Jung;Do, Wan-Nyeo;Kim, Yong-Ho
    • The Korean Journal of Food And Nutrition
    • /
    • v.22 no.1
    • /
    • pp.150-157
    • /
    • 2009
  • The purpose of this study was to analyze the anthocyanin contents of black soybean crude extracts derived using a countercurrent system and to compare the effects of stabilizers(${\beta}-cyclodextrin$, maltodextrin) and sugars(sucrose, maltose) on the color deterioration of the anthocyanin. When the extraction process was kept at 100$^{\circ}C$ for 120$\sim$180 min, only C3G (cyanidin-3-glucoside) was detected in the water extract. The C3G contents in the water extracts acquired at 8$^{\circ}C$, 60$^{\circ}C$, and 80$^{\circ}C$ were 2.38 ppm, 1.73 ppm, and 1.73 ppm, respectively. Sucrose and maltose retarded color deterioration of the crude pigment extract by the countercurrent method with methanol. Finally, the additions of maltodextrin or ${\beta}-cyclodextrin$ did not retard thermal color deterioration of the black soybean crude pigment extract.