• Title/Summary/Keyword: basic physical properties

Search Result 608, Processing Time 0.034 seconds

Studies of concrete utilization of waste sludge by-producted in aggregate mines (석산골재광산에서 발생한 잔토의 콘크리트 유효이용에 대한 연구)

  • 엄태선;백상현;백원준;김창수
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 1998.10c
    • /
    • pp.7-12
    • /
    • 1998
  • The waste sludge is by-produced about 20-30% of total production and arised to the severe problems of this mine's surrounding environmnet. This study was invested the composition of component, particle of size of the waste sludge by Chemical Analysis, X, R, D, Particle Size Analyzer and the physical properties (air content, slump, strength, etc) of concrete when the waste sludge is added into concrete. so, It's recomended the proper content of the waste sludge to be added into concrete. and then, is verified to be applied at batch plant in field. Above the results, the recomeded content of the waste sludge is about 2-4% (about 4-8% in cement) in aggregates and when it's added the recomended content, they are detected to be more or less changed the physical properties of concrete, ( equally strength and durability, little less air con tent, little increased shinkage, etc). but the application of the recomended content don't arise the problem of the basic quality control of concrete and physical properties.

  • PDF

An Experimental Study on the physical-mechanical Properties of Ultra-High-Strength-Concrete (초고강도 콘크리트의 물리적·역학적 특성에 관한 실험적 연구)

  • Park, Hee-Gon;Lee, Jin-Woo;Bae, Yeoun-Ki;Kim, Woo-Jae;Lee, Jae-Sam;Jung, Sang-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2008.11a
    • /
    • pp.107-111
    • /
    • 2008
  • As high-rise buildings with 100 or more stories are being constructed, it is inevitable to use high-performance materials including high-performance concrete. What is most important in high-performance concrete is extremely high strength in order to reduce the section of members in high-rise buildings. During the last several years, there have been active researches on Ultra-high-strength concrete. While these researches have been mostly focused on strength development, however, other accompanying physical properties have not been studied sufficiently. Thus, this study purposed to obtain and analyze data on the physical-mechanical properties of Ultra-high-strength concrete through experiments and to use the results as basic information on required performance of concrete used in high-rise buildings.

  • PDF

Effects of Curing Methods on the Quality of Cured Leaves in Burley Tobacco (N. tabacum L.) (버어리종 건조방법이 건엽의 품질에 미치는 영향)

  • 배성국;조천준;임해건;김요태
    • Journal of the Korean Society of Tobacco Science
    • /
    • v.20 no.1
    • /
    • pp.26-32
    • /
    • 1998
  • This study was conducted to obtain the basic information on the burley tobacco (Nicotiana tabacum L.) curing methods. The effects of the three kinds of curing methods on the dry weight losses during curing, chemical contents and physical properties of cured leaves, and organoleptic and smoking qualities were observed. The dry weight losses during curing was the highest in the stalk curing, and the lowest in the conventional priming. The longer the curing periods was, the more the loss of dry weight. The percent of the excessive dried leaves was high and the price per kilogram was low in the conventional priming. The chemical contents and the physical properties of the cured leaves in the conventional priming were similar to those of yellowing or browning stage of curing. But, the chemical contents and the physical properties of the cured leaves in the stalk curing were comparable to those of the air curing. The smoking quality was the best in the stalk curing.

  • PDF

Wood Physical and Mechanical Properties of Clonal Teak (Tectona grandis) Stands Under Different Thinning and Pruning Intensity Levels Planted in Java, Indonesia

  • Gama Widya SETA;Fanny HIDAYATI;WIDIYATNO WIDIYATNO;Mohammad NA'IEM
    • Journal of the Korean Wood Science and Technology
    • /
    • v.51 no.2
    • /
    • pp.109-132
    • /
    • 2023
  • The objective of this study was to reveal the impact of thinning and pruning regimes on the physical and mechanical properties of clonal teak wood planted in Java. In this study, a 15-year-old clonal teak plantation was carried out and the obtained data were evaluated with analysis of variance (ANOVA). The results showed that different thinning intensities had a significant impact on the alteration of heartwood volume development (F = 25.63; p < 0.0001). Meanwhile, the impact of different thinning treatments in several physical properties depends on the pruning treatment levels [moisture content (F= 12.18, p < 0.0001); tangential shrinkage (F = 15.60, p < 0.0001); T/R ratio (F = 7.17, p < 0.0001); and volumetric shrinkage (F = 10.81, p < 0.0001)]. However, different thinning intensities had no significant impact on wood basic density alteration (F = 0.72, p = 0.486), while pruning intensities affect the differences between radial (F = 3.52, p = 0.030) and volumetric shrinkage (F = 3.13, p = 0.044). In mechanical properties, thinning intensity levels did not promote any significant differences [modulus of elasticity (F = 1.41, p = 0.248); modulus of rupture (F = 0.94, p = 0.392); compressive strength parallel to grain (F = 0.21, p = 0.813); and compressive strength perpendicular to the grain (F = 0.41, p = 0.669)]. Meanwhile, different pruning treatments and combination treatments were not significantly altered all mechanical properties. These results indicated that the thinning and pruning regimes can enhance the mechanical properties without having a serious alteration in the physical properties of clonal teak wood.

A Study on Various Effecting Factors on Water Proofing Properties of Cement Mortar (시멘트 몰탈의 방수성능에 미치는 제반 영향인자에 관한 연구)

  • 신도철;이종열
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 1995.04a
    • /
    • pp.100-105
    • /
    • 1995
  • The aim of this study is to developed water proofing properties of cement mortar this study the effect of mix proportion on the basic characteristics of cement mortar was investigated. Also water absorption and permeability properties of mortar using several admixtures were tested. from this results, Physical properties of mortar is improved by using the sand witch has a broad particle size distribution. Also the sililca alumina powder is effective for decreasing the water permeability of mortar and zinc stearate is in creasing the water repellence property.

  • PDF

The Change of the Physical Properties of Rayon/Cotton Blend Fabrics Treated with Cellulase by Addition of Silicon (셀룰라아제 처리시 실리콘 첨가에 따른 레이온/면 혼방직물의 물성변화)

  • 이선화;송화순
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.22 no.8
    • /
    • pp.1032-1042
    • /
    • 1998
  • The purpose of this study is to measure, compare, and investigate the physical properties of rayon/cotton blend fabrics treated with cellulase and cellulase & specific degeneration silicon and to present basic data which is in development a value-added fabric. The results are as follows. The condition for the treatment of cellulase was at 55$^{\circ}C$, pH 4 and the weight loss increased as the concentration of cellulase and the treated time increased. On treatment with cellulase, the crossectional view & longitudinal view of fiber noticed remarkable crack as weight loss increased and tensile strength and elongation decreased, and pilling was enhanced remarkably. KOSHI was increased, NUMERI and FUKURAMI were decreased as weight loss increased. In the basic characteristic value of clothing wearning, shape stability and drapability were decreased, but air content was improved. On treatment with cellulase & silicon, the degree of damage in the crossectional view & longitudinal view of the fiber reduced. Tensile strength, elongation, moisture regain improved. KOSHI and FUKURAMI were reduced, NUMERI was improved rather than when it was treated with cellulase. Therefore handle was improved. In the basic characteristic value of the clothing wearing, shape stability, air content, drapability were improved.

  • PDF

Physical Properties and Dyeability of Fine Count Wool Yarns and Its Fabrics by Drawing Process of Fineness Control (섬도제어 연신공정에 의한 세섬화 양모 소재의 물성 연구)

  • Kim, Mikyung;Jeon, Byeongdae;Jeong, Jaeseok
    • Textile Coloration and Finishing
    • /
    • v.28 no.4
    • /
    • pp.253-270
    • /
    • 2016
  • In the wool textile industry, the necessity for technology development has been steadily raised to create improved fineness and yarn count of existing wool yarns with thick fineness for ensuring higher quality grades of wool yarn. Recently, through controlling fineness of wool yarn for making finer wool in relation with environmentally-friendly and high-sensitivity trend, a differentiated continuous drawing process where the quality of wool can be artificially manipulated has been suggested in the latest textile industry. This study investigated the basic conditions during the continuous drawing process which enable to manufacture wool yarn with fine count by controlling reducing agent treatment, physical drawing and drying after reducing agent treatment, and oxidizing agent post-treatment conditions. Furthermore, this study reviewed the drawing effects by applying the basic conditions for reduction and oxidation reaction in the drawing processes of wool/cashmere, wool/silk, wool/polyester blended yarns as well as such wool yarns. Also, in order to review the practicability, this study examined the physical properties and dyeability of drawn wool yarn applied textile materials in comparison with normal wool yarn applied textile materials.

Electrical Properties and Lifetime Prediction of Epoxy/$SiO_2$Composites with Water Absorption Ageing (흡수열화에 따른 Epoxy/$SiO_2$ 복합체의 전기적 특성 및 수명예측)

  • 김탁용;이덕진;홍진웅
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.13 no.9
    • /
    • pp.758-763
    • /
    • 2000
  • Dielectric strength of insulators made of epoxy composites rapidly decreases due to ageing to interfaces between the matric resin and filler particles. The adhesion variation of interfaces caused by moisture absorption also alters electrical properties that are the basic characteristics of insulators, particularly, in outdoor use. In this paper, electrical properties of epox/SiO$_2$composites were investigated at boiling absorption condition to observe the influences of moisture. In order to analyze the basic physical properties of samples, scanning electron microscopy and DC, AC and impulse voltage dielectric strength were measured. Also, the breakdown time of samples was measured under AC 6[kV] applied voltage, and the variation of lifetime was verified by using Weibull distribution function.

  • PDF

Effect of Tannin-weighting Process in Dyeability and Physical Properties of Silk (탄닌 증량 효과에 따른 견섬유의 염색성과 물성)

  • Kim, In Young
    • Textile Coloration and Finishing
    • /
    • v.6 no.4
    • /
    • pp.62-71
    • /
    • 1994
  • The weighting increase varies with the condition of tannin-weight process and effects dyeability and physical properties of silk. The purpose of this study is to investigate the optimum condition of tannin-weighting process of silk and the effect of tannin-weighting process on dyeability and properties of silk. The methods of this study are first to examine the change according to the variables such as, weight increase of silk, temperature(30, 50, 70, 80, 9$0^{\circ}C$), time(30, 60, 120, 180, 240, 300min), tannin concentration(3, 5, 10, 20, 30g/l) in order to present the optimum condition, sencond to examine the change of the properties such as surface morphology, strength, elongation, mechanical values, dyeing condition, Basic and Acid dye absorption on silk which are tannin-weight processed in the optimum condition.

  • PDF

Effect of raw materials of the papermaking and physical treatment on the pore structure and properties of the paper (주요제지원료의 특성 및 고해가 종이의 pore structure 및 물성에 미치는 영향)

  • Nam, Ki-Young;Chung, Soon-Ki;Won, Jong-Myoung
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
    • /
    • 2007.11a
    • /
    • pp.127-134
    • /
    • 2007
  • Paper is composed network of fibers. Since paper is plain, most cases paper is considered two-dimensional. But network of fibers creates a network of pores, and pores between fibers are most important part of the paper structure. So we have to make an approach to the paper by three-dimensionally. Pore structure in the Z-direction of the paper can affect directly not only basic properties od the paper such as density, porosity, opacity and strength but also coverage of the coating colors during coatong and printing properties. We studied effect of raw materials of the papermaking and physical treatment on the pore structure and properties of the paper.

  • PDF