• Title/Summary/Keyword: 현장 재료 강도

Search Result 419, Processing Time 0.032 seconds

A Study on the Computer application of basic design courses (디자인 기초 교과목의 컴퓨터 응용연구)

  • 도화용;문재호
    • Archives of design research
    • /
    • v.15 no.2
    • /
    • pp.37-46
    • /
    • 2002
  • As the use of computer has become popular it is now essential also in designing tools that the common design tools we have been using are now disappearing. The educational institutions have long started using computers as teaching materials to help students adjust to the real world. Let us introduce a new educational method in drawing, one of the basic courses, using imputer application softwares together with application of the conventional drawing instruments.

  • PDF

용접작업 공정에서의 위험성과 안전대책

  • 김용수;권오헌
    • Bulletin of the Korean Institute for Industrial Safety
    • /
    • v.2 no.1
    • /
    • pp.17-23
    • /
    • 2002
  • 용접작업공정은 기본적으로 2개 이상의 부재인물체나 재료를 상호 접합시키는 공정으로서 산업의 광범위한 분야에 이용되고 있다. 특히, 각종 설비, 교량의 구축 등에 필수적이며, 최근 고강도화, 경량화, 초정밀화를 추구하는 자동차, 항공기, 전자 및 광학기기, 가전제품 및 산업용기기 등의 품질경쟁력이 가공기술에 좌우됨에 따라 첨단 용접가공 프로세스가 개발되어 사용되고 있으나 대부분의 산업현장에서는 아직도 종래의 가스용접 및 전기용접장치를 많이 사용하고 있다. 따라서 산업현장의 실태는 유해.위험공정인 용접작업에 의하여 여전히 재래식 재해가 발생되어 사망 및 신체장애 재해가 다발하고 있다. 여기서는 교류아아크 용접작업과 $CO_2$ 아아크 용접작업 재해의 예방기술에 대하여 간략히 소개한다. 게재된 내용은 한국산업안전공단에서 제공된 자료를 발췌 정리한 것이다.(중략)

  • PDF

A Study on the Specialized Mix Design of Mine Sprayed Concrete Using Industrial Byproducts (산업부산물(産業副産物)을 이용(利用)한 광산(鑛山) 스프레이 콘크리트의 물성연구(物性硏究))

  • Ma, Sang-Joon
    • Resources Recycling
    • /
    • v.22 no.3
    • /
    • pp.18-27
    • /
    • 2013
  • In this study, it was developed eco-friendly mix design of mine sprayed concrete, which satisfies both the stability and economics by mixing the industrial in cement, for development of the mine sprayed concrete and recycling of industrial. From this research, it is found that mixing of mineral admixture is effective on strength enhancement. Also, it is considered that designed mixing ratio of sprayed concrete using industrial byproducts should be applied to the field through field test.

Assessments of Installation Damage and Creep Deformation of Geogrids (지오그리드의 시공시 손상 및 크리프 변형 특성 평가)

  • Cho, Sam-Deok;Lee, Kwang-Wu;Oh, Se-Yong;Lee, Do-Hee
    • Journal of the Korean Geosynthetics Society
    • /
    • v.3 no.4
    • /
    • pp.29-40
    • /
    • 2004
  • The factors affecting the long-term design strength of geogrids can be classified into factors on creep deformation, installation damage, temperature, chemical degradation, biological degradation. Especially, creep deformation and installation damage are considered as main factors to determine the long-term design strength of geogrids. This paper describes the results of a series of experimental investigation, which were conducted to assess the installation damage according to different fill materials and creep characteristic of various geogrids. The results of this study show that the installation damage and creep deformation of geogrids significantly depends on a row material and a manufacturing process of geogrids.

  • PDF

A Proposal of Elastic Modulus Equation for High-Strength and Ultra-High-Strength Concrete (국내의 실험자료를 이용한 고강도 및 초고강도 콘크리트의 탄성계수식 제안)

  • 장일영;박훈규;윤영수
    • Magazine of the Korea Concrete Institute
    • /
    • v.8 no.6
    • /
    • pp.213-222
    • /
    • 1996
  • This paper presents the improved elastic modulus equation more appropriate to predict the modulus of elasticity of structural elements designed and made by high- and ultra high-strength concrete under domestic situation in Korea. To justify and assess the proposed elastic modulus equation, more than 400 laboratory test data domestically available in the literature and having the range of 400 to 1.000kg/$\textrm{cm}^2$ in concrete compressive strength were collected and analyzed statistically. Comparison of the proposed elastic modulus equation with the previously suggested equations in the ACI363R. CEB-FIP, NS3473 and New-RC were also presented to demonstrate the applicability to practice.

Estimation of Flowability and Strength in Controlled Low Strength Material Using Multiple Regression Analysis (다중회귀분석을 이용한 CLSM의 유동성 및 강도 특성 예측)

  • Han, WooJin;Lee, Jong-Sub;Byun, Yong-Hoon
    • Journal of the Korean GEO-environmental Society
    • /
    • v.18 no.12
    • /
    • pp.65-75
    • /
    • 2017
  • Flowability and strength with curing time of controlled low-strength material (CLSM) are required differently according to the construction purpose. In this paper, the flowability and strength were estimated from the mixing ratio of CLSM using multiple regression analysis to design the CLSM. The flow values and strength at 12 hrs and 7days were measured in accordance with the mixing ratio of CLSM which consists of 7 different materials, such as CSA expansive agent, ordinary Portland cement, fly ash, sand, silt, water, and accelerator. The multiple regression was performed with the proportions of each material of CLSM as independent variables and the measured properties as dependent variables using SPSS Statistics 23 which is a statistical analysis program. The regression coefficients were estimated from the first to third order equation models for the materials. From the results, the third order model for the flow values and the first order models for 12hrs and 7days strength are the most appropriate models. This study suggests that the mixing ratio required for constructions may be effectively estimated from the regression models about the characteristics of CLSM, before performing experimental tests.

기술초대석 - 포스트텐션 공법 소개

  • Gang, Do-An;Lee, Seong-Hui
    • 건축구조
    • /
    • v.17 no.1
    • /
    • pp.78-83
    • /
    • 2010
  • 포스트텐션(Post-Tension, PT) 공법은 일반적으로 텐던(tendon)으로 알려진 고강도 강선 또는 봉을 이용하여 콘크리트 또는 다른 재료를 보강하는 방법으로 많은 경우 건설현장의 제약과 건축적인 요구에 의해 다른 공법으로 해결이 불가능한 경우에 대해 대안으로 사용되어 온 공법이다. 또한 포스트텐션 시스템은 조립과 설치에 특수한 지식과 경험이 필요하였다. 그러나 최근 건설시장은 신소재와 신공법의 발달과 함께 친환경 및 경제성에 대한 요구가 증가함에 따라 장스팬 및 층고절감이 가능한 포스트텐션 공법을 일반 건축물에 적용하는 사례가 점차 늘어나는 추세에 있다. 따라서 본 지에서는 3회에 걸쳐 포스트텐션 공법과 설계 및 시공사례 등을 소개하고자 한다. 1. 포스트텐션 공법 소개 2. 포스트텐션 공법의 경제성 비교 3. 포스트텐션공법의 설계사례와 설계시 고려사항

  • PDF

Effect of Waste Glass Wool on Mechanical Properties of Concrete (폐글라스울이 콘크리트의 역학적 특성에 미치는 영향)

  • Kim, Jeong-Tae;Choi, Woo-Hyuk;Chung, Chul-Woo;Lee, Jae-Yong
    • Journal of the Korea Institute of Building Construction
    • /
    • v.16 no.2
    • /
    • pp.117-123
    • /
    • 2016
  • Glass wool is a material that has been used as a heat insulator in various fields including construction industry. Since it is a nonflammable material, it does not generate toxic gases on fire, and thus public agencies recommend using glass wool as a heat insulator instead of other organic materials. However, repeated drying and wetting cycles can deteriorate thermal property of glass wool due to the shrinkage and reduction in pore size. For this reason, it needs to be replaced periodically, and waste materials are generated. This research aims to utilize waste glass wool as additives for increasing mechanical properties of concrete. According to the experimental results, it was found that glass wool has weak pozzolanic activity, and beneficial effect on both compressive and flexural strength. The optimum amount found in this experimental work was 0.5% volumetric addition to the concrete.

Development of Domestic Pattern Frame Method for Skid Resistance Pavement (미끄럼 방지 도로 포장을 위한 국내형 패턴 프레임 공법 개발)

  • Lee, TaeMin;Choi, HaJin
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.25 no.2
    • /
    • pp.58-65
    • /
    • 2021
  • As increasing social needs of pavement maintenance, pattern frame method has been constructed in Korea. The pattern frame not only increases the skid resistance of pavements but also improve the scenery. However, construction of the pattern frame currently relies on imported materials. In this paper, we localize the materials used in pattern frame and conduct performance verification on them. The important performance indicators are the adhesion strength of undercoating materials and the skid resistance of finished pattern frames. The adhesion strength was targeted at 1.4MPa, and the localization alternative material met the target performance with 2.35MPa, the skid resistance performance was targeted at 40BPN, and the localization alternative material met the target performance with 75BPN. In the case of localized materials, approximately 40% cost reduction (per 1m2)compared to imported materials was confirmed.

A Study on Manufacture standardization of High Strength Concrete to Use Moderate Heat Portland Cement (벨라이트계 시멘트를 이용한 고강도 콘크리트 제조표준화에 관한 연구)

  • Park, Cheol;Kim, Dong-Suck;Um, Tai-Sun;Lee, Jong-Ryul
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2008.04a
    • /
    • pp.665-668
    • /
    • 2008
  • Recently the city construction and the concrete structures are more becoming extra weight and the efficient use of the space by the population intensively and follow in industrial intensive commerce and the residence commerce composition building which leads the high story of the building. Consequently the high rise of the building which space applies efficiently in objective which will increase continuously. Also with high rise of buildings durability it will be able to increase the life of the structure is emphasized and the concrete structure is demanding the more high strength.

  • PDF