• Title/Summary/Keyword: Physical property test

Search Result 296, Processing Time 0.028 seconds

The Support Types of the Tunnel for Centrifuge Model (터널의 지보방법에 관한 원심모형실험(遠心模型實驗))

  • Yoo, Nam-Jae;Lee, Myung-Woog;Park, Byung-Soo
    • Journal of Industrial Technology
    • /
    • v.22 no.B
    • /
    • pp.199-209
    • /
    • 2002
  • This research is experimental thesis to prepare the structural safety of the upper bridge for support type on tunnel and the effect of settlement. Unit weight test and uni-axial compression test have been performed to simulate the physical property of foundation on the tunnel. Tunnel model of slip form type for centrifuge model has been developed to performed the tunnel excavation while field stress is activated. And the support type of tunnel such as umbrella arch method and large diameter steel pipe reinforce method has been tested for the centrifuge model. After the analysis of experiment, results show that internal displacement of large diameter steel pipe reinforce method is smaller than that of the umbrella arch method.

  • PDF

Studies on Wood-based Composite Panel with Waste Tire - Properties of Composite Boards in Relation to Hot Pressing Conditions - (폐타이어를 이용한 목질계 복합판넬의 연구 - 열압조건에 의한 재질특성 -)

  • Lee, Weon-Hee;Park, Sang-Jin
    • Journal of the Korean Wood Science and Technology
    • /
    • v.25 no.4
    • /
    • pp.29-38
    • /
    • 1997
  • The effect and control of wood property of reconstituted composite panels for improved board properties by wood-waste materials and development of combination method for heterogeneous materials have been of interest to the wood science researchers. The purpose of this study is to consider the properties in relation to hot pressing conditions and to develope the optimum hot pressing condition with waste wood and waste tire for the manufacturing of composite boards. The study of composite boards for recycling of wood and waste tire is nothing up to the present. Physical and mechanical properties such as specific gravity, moisture content, swelling coefficient, modulus of rupture and modulus of elasticity in bending test were studied. The condition of 3-stage press time for the lowest moisture content of composite board was $4{\rightarrow}3{\rightarrow}3$ minutes. Specific gravity of composite panels was affected mainly by the amount of rubber chip. Because of the low rigidity and high elasticity in rubber chip, it is considered the composite panel was adequate material in the place of compression load, but not bending load. Therefore, it was concluded that a use of rubber-based wood composite panel is proper to the interior materials such as floor a room than exterior materials. From the test results, the most optimum hot pressing conditions were $4{\rightarrow}3{\rightarrow}3$ minutes for 3-stage press time and $45{\rightarrow}20{\rightarrow}5kg/cm^2$ for 3-stage press pressure. The rubber-based wood composite panel was very excellent in elasticity by combination of rubber chip in comparison with existing other wood-based materials. Therefore, it was considered that rubber-based wood composites can be applicable to every interior materials such as floor a room and will be expected to effective reuse and recycle of waste tires and wood-waste materials, and will be contribute to protection of environment pollution in earth.

  • PDF

Development of Additive to Modify the SDAR (Solvent DeAsphalting Residue) and Laboratory Performance Evaluation of Asphalt Mixture with Modified SDAR (고품위화 정제공정 부산물(SDAR) 활용을 위한 첨가제 개발 및 이를 이용한 아스팔트 혼합물의 실내 공용성능 평가)

  • Baek, Cheolmin;Yang, Sung Lin;Hwang, Sung Do
    • International Journal of Highway Engineering
    • /
    • v.18 no.6
    • /
    • pp.97-104
    • /
    • 2016
  • OBJECTIVES : The objective of this research is to develop additives for the modification of Solvent DeAsphalting Residue (SDAR) to be used as pavement materials, and evaluate the performance of asphalt mixture manufactured using the SDAR modified by developed additives. METHODS : The SDAR generally consists of more asphaltenes and less oil components compared to the conventional asphalt binder, and hence, the chemical/physical properties of SDAR are different from that of conventional asphalt binder. In this research, the additives are developed using the low molecular oil-based plasticizer to improve the properties of SDAR. First, the chemical property of two SDARs is analyzed using SARA (saturate, aromatic, resin, and asphaltene) method. The physical/rheological properties of SDARs and SDARs containing additives are also evaluated based on PG-grade method and dynamic shear-modulus master curve. Second, various laboratory tests are conducted for the asphalt mixture manufactured using the SDAR modified with additives. The laboratory tests conducted in this study include the mix design, compactibility analysis, indirect tensile test for moisture susceptibility, dynamic modulus test for rheological property, wheel-tracking test for rutting performance, and direct tension fatigue test for cracking performance. RESULTS : The PG-grade of SDARs is higher than PG 76 in high temperature grades and immeasurable in low temperature grades. The dynamic shear modulus of SDARs is much higher than that of conventional asphalt, but the modified SDARs with additives show similar modulus compared to that of conventional asphalt. The moisture susceptibility of asphalt mixture with modified SDARs is good if, the anti-stripping agent is included. The performance (dynamic modulus, rutting resistance, and fatigue resistance) of asphalt mixture with modified SDARs is comparable to that of conventional asphalt mixture when appropriate amount of additives is added. CONCLUSIONS : The saturate component of SDARs is much less than that of conventional asphalt, and hence, it is too hard and brittle to be used as pavement materials. However, the modified SDARs with developed additives show comparable or better rheological/physical properties compared to that of conventional asphalt depending on the type of SDAR and the amount of additives used.

Measurement of Mechanical and Physical Properties of Pepper for Particle Behavior Analysis

  • Nam, Ju-Seok;Byun, Jun-Hee;Kim, Tae-Hyeong;Kim, Myoung-Ho;Kim, Dae-Cheol
    • Journal of Biosystems Engineering
    • /
    • v.43 no.3
    • /
    • pp.173-184
    • /
    • 2018
  • Purpose: This study was conducted to investigate the mechanical and physical properties of a Korean red pepper variety for particle behavior analysis. Methods: Poisson's ratio, modulus of elasticity, shear modulus, density, coefficient of restitution, and coefficient of friction were derived for "AR Legend," which is a domestic pepper variety. The modulus of elasticity and Poisson's ratio were measured through a compression test using a texture analyzer. The shear modulus was calculated from the modulus of elasticity and Poisson's ratio. The density was measured using a water pycnometer method. The coefficient of restitution was measured using a collision test, and the static and dynamic friction coefficients were measured using a inclined plane test. Each test was repeated 3-5 times except for density measurement, and the results were analyzed using mean values. Results: Poisson's ratios for the pepper fruit and pepper stem were 0.295 and 0.291, respectively. Elastic moduli of the pepper fruit and pepper stem were $1.152{\times}10^7Pa$ and $3.295{\times}10^7Pa$, respectively, and the shear moduli of the pepper fruit and pepper stem were $4.624{\times}10^6Pa$ and $1.276{\times}10^7Pa$, respectively. The density of the pepper fruit and the pepper stem were $601.8kg/m^3$ and $980.4kg/m^3$, respectively. The restitution coefficients between pepper fruits, pepper stems, a pepper fruit and a pepper stem, a pepper fruit and plastic, and a pepper stem and plastic were 0.383, 0.218, 0.277, 0.399, and 0.148, respectively. The coefficients of static friction between pepper fruits, pepper stems, a pepper fruit and a pepper stem, a pepper fruit and plastic, and a pepper stem and plastic were 0.455, 0.332, 0.306, 0.364, and 0.404, respectively. The coefficients of dynamic friction between a pepper fruit and plastic and a pepper stem and plastic were 0.043 and 0.034, respectively.

Characterization of Soldering Property on Heating Condition by Infrared Lamp Soldering Process for C-Si Photovoltaic Modules (적외선 램프 가열방식을 이용한 태양전지 셀의 솔더링 공정 및 열처리 조건 별 특성 평가)

  • Son, Hyoun Jin;Lee, Jung Jin;Kim, Sung Hyun
    • Current Photovoltaic Research
    • /
    • v.4 no.2
    • /
    • pp.59-63
    • /
    • 2016
  • A key point of a soldering process for photovoltaic (PV) modules is to increase an adhesive strength leading a low resistivity between ribbon and cell. In this study, we intended to optimize a heating condition for the soldering process and characterize the soldered joint via physical and chemical analysis methods. For the purpose, the heating conditions were adjusted by IR lamp power, heating time and hot plate temperature for preheating a cell. Since then the peel test for the ribbon and cell was conducted, consequently the peel strength data shows that there is some optimum soldering condition. In here, we observed that the peel strength was modified by increasing the heating condition. Such a soldering property is affected by a various factors of which the soldered joint, flux and bus bar of the cell are changed on the heating condition. Therefore, we tried to reveal causes determining the soldering property through analyzing the soldered interface.

Effect of Blast Furnace Slag, Hwang-toh and Reinforcing Fibers on The Physical and Mechanical Properties of Porous Concrete Using Blast Furnace Slag Coarse Aggregate (고로슬래그 골재를 사용한 다공성 콘크리트의 물리·역학적 특성에 미치는 고로슬래그 미분말, 황토 및 보강섬유의 효과)

  • Lee, Jin-Hyung;Park, Chan-Gi
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.52 no.5
    • /
    • pp.53-60
    • /
    • 2010
  • The effects of blast furnace slag, hwang-toh, and reinforcing fiber on the physical and mechanical properties of porous concrete using blast furnace slag coarse aggregates have been evaluated in this study. The effect of the depending on replacement ratio of blast furnace slag to cement was investigated such that the replacement ratio was varied to 0 %, 25 % and 50 %. Also, the replacement ratios of hwang-toh were 0, 20 and 30 %. The polyvinyl alcohol fiber was used for the reinforcing fiber. A series of pH, unit mass, and void ratio tests have been performed to study the physical properties of the porous concrete using blast furnace slag coarse aggregates with the polyvinyl alcohol fiber and the replacement ratios of blast furnace slag, hwang-toh, while a series of compressive tests have been performed to evaluate the strength property depending on polyvinyl alcohol fiber and the replacement ratios of blast furnace slag, hwang-toh. The test results indicated that the physical and mechanical properties of porous concrete using blast furnace slag coarse aggregates is affected by the replacement ratio of blast furnace slag, and the fiber contents. According to the tests with polyvinyl alcohol fiber contents, the void ratio was decreased and the compressive strength was upgraded.

A Study on Physical Properties of $PAN-CuSO_4$ Electroconductive Fiber and Wool Blended Fabrics (아크릴-황산동 복합체로 제조한 도전성 섬유 및 혼방한 모직물의 물성에 관한 연구)

  • 정영진;이명환;최해욱;이기환
    • Textile Coloration and Finishing
    • /
    • v.11 no.4
    • /
    • pp.8-15
    • /
    • 1999
  • Electroconductive fiber was obtained by acryl fiber treated with $CuSO_4$. The Properties and structure of fiber and fabric such as mechanical property, electrical conductivity, fine structure, electrification were investigated. The experimental results are as follows 1) The electrical conductivity of the conducting fiber was greatly increased but fine structure and physical properties were similar to acryl fiber 2) Fabric made by mix spinning with conducting fiber was shown great electrification effect. 3) In the mix spinning with conducting fiber, it was necessary to use different. finishing such as milled finish because stiffness of fabric made by mix spinning with conducting fiber was increased and elastic recovery was decreased. 4) The antimicrobial activity of electroconductive fiber blended wool was effective by Cu component for shake flask test.

  • PDF

An Experimental Study on the Relationship Between Physical Property of Recycled Aggregates and an Amount of Mortar Attached to the Original Aggregate (재생골재의 물리적 성질과 모르타르 부착양의 관계에 대한 실험적 연구)

  • Kim Hyun-Ho;Yang Keun-Hyeok;Kang Kyung-In;Jung Sang-Jin;Chung Heon-Soo
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2005.05b
    • /
    • pp.141-144
    • /
    • 2005
  • This paper reports the results of experimental study on the effect of an amount of mortar attached to the surface of original aggregate on the physical properties of recycled aggregates such as specific gravity, and water absorption. An amount of attached mortar was evaluated by hydrochloric acid precipitation method. Test results indicated that a water absorption of recycled aggregates was proportional to the amount of mortar attached to the original aggregate.

  • PDF

Relationship between Physical Property of Re-agglomerated Floc and Turbulent flow (난류모델을 이용한 재응집 Floc의 물리적 특성 연구)

  • Park, No-Suk;Kim, Seong-Su;Kim, Kwan-Youp;Kim, Jong-Oh
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.24 no.1
    • /
    • pp.103-108
    • /
    • 2010
  • Until now, research reports that it is difficult for brokenup floc after coagulation to reaggregate and settling efficiency of reaggregated floc is relatively low have dominated in water treatment process. In contrast, from recent study conducted by the French researcher, because the density of the reaggregated floc was higher than the previous floc, the settling efficiency of reaggregated floc increased. In this study, 15 times wet test were carried out and the removal efficiency of reagrregated floc was considerably increased. Moreover, this result was explained using the turbulent model for the flow occurred around the floc. Consequently, in the case of suitable hydrodynamic condition for the reaggregation, the characteristics of the reaggregated floc was changed into the favorable condition for improvement of settling efficiency. Also, the most important factor for reaggregation of floc was governed by hydrodynamic shear stress.

Physical and Sensory Properties of Rice Gruels and Cakes Containing Different Levels of Ginkgo Nut Powder (은행 분말을 첨가한 죽 및 떡의 물리적 및 관능적 특성)

  • Kim, Jung-Mi;Suh, Dong-Soon;Kim, Young-Suk;Kim, Kwang-Ok
    • Korean Journal of Food Science and Technology
    • /
    • v.36 no.3
    • /
    • pp.410-415
    • /
    • 2004
  • Effects of ginkgo nut powder content on physical and sensory properties, and consumer acceptability of ginkgo nut gruel and cake were examined. In ginkgo nut gruel, greenness and consistency decreased, and sensory color intensity and ginkgo nut flavor increased with increasing ginkgo nut powder content. Consumer acceptability test indicated ginkgo nut powder : rice flour ratio at 4 : 6 had the highest overall and flavor acceptabilities. In ginkgo nut rice cakes, as ginkgo nut powder content increased, greenness, adhesiveness, sensory hardness, and cohesiveness of mass decreased, while sensory color intensity, ginkgo nut flavor, and chalkiness increased. Ginkgo nut cake with ginkgo nut powder : rice flour ratio at 16 : 84 had highest overall acceptability.