• 제목/요약/키워드: Curing Method

검색결과 1,071건 처리시간 0.024초

탄소중립 확보를 위한 친환경 동절기 대체 열원 성능 검증 (Performance Verification of Curing Method in Cold-Weather with Using Energy Saving Electronic Heater for achieving Korean Carbon Neutra)

  • 조만기;김상균;홍성민;박종훈
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2021년도 가을 학술논문 발표대회
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    • pp.192-193
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    • 2021
  • Recently, the need to strengthen the Air Environment Conservation Act and secure alternative heat sources during the winter by carbon neutrality policies has been raised. Accordingly, winter construction, which has safety and quality measures, is emerging as an essential factor. It is believed that eco-friendly tropical type electric hot air heaters will be able to solve most of the problems of winter construction at construction sites, especially prevention of suffocation and fire accidents. In addition, as a result of on-site performance verification, it has secured more than the same performance as the existing curing method, and the curing technology can create an eco-friendly and pleasant working environment while considering safety and construction.

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알칼리 첨가 및 양생방법에 따른 슬래그 경화체의 특성 (The Properties of Hardened Slag by Alkali and Curing Method)

  • 김원기;소정섭;배동인
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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    • pp.27-32
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    • 2002
  • In this research influences of type and concentration of alkali activator and curing condition on the hydration, and properties of alkali activated blast furnace slag(AAS) concrete were investigated. Sodium carbonate and sulfate were used as alkali activators and their concentration were 4~10 weight percent with Na$_2$O equivalent to binder. The curing conditions were standard curing using 23$^{\circ}C$ water and activated curing chamber at $65^{\circ}C$. Results show that in case of sodium carbonate addition high early strengths were gained by activation of early hydration, but later strength gained was slight. On the other side sodium sulfate strengths were continuously increased with adding amount and ages. Steam curing activated early hydration so that early strengths were improved but later strengths were similar to standard curing. The strength reduction of AAS mortar with sodium sulfate was less than OPC mortar in 5% sulfuric acid solution so that AAS concrete can be useful for acid-resistance concrete.

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고로슬래그 미분말을 사용한 콘크리트 흄관에 대한 기초적 연구 (The Basic Study on the Spun Concrete Pipes using Blast-Furnace Slag Powder)

  • 조영근;김승진;박유신;성기웅;손진군
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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    • pp.939-944
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    • 2000
  • This study examines both strength development and pore volume of high temperature curing mortar, using a blast-furnace slag powder (BFS). This study experiments with various pre-steaming period, differing curing temperature and the replacement of BFS. According to the results, the strength development of BFS mortar is stronger when higher curing temperature are used(as opposed to standard curing). Also, regardless of the curing method, pore volume decreases as the curing time increases. From these results we can identify the optimum conditions required pre-steaming period, differing curing temperature and the replacement to produce BFS mortar properties.

Multi-Piezo 헤드를 이용한 3차원 프린팅 기법 (3DP Printing Method using Multi-Piezo Head)

  • 김정수;김동수;이민철
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.1394-1399
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    • 2007
  • Recently, Study of 3D freeform fabrication method was working in the various applications. For example, in the powder base, it's laminated using a binding method or laser sintering method. However, these methods are not suitable in the office environments because it dust with powder that is bad for health. In this paper, we introduce a method of 3D freeform fabrication using a curing of photo-polymer resin and construct a system has multi printing head. A photo-polymer curing method has simply fabrication process and high strength of manufacturing part. However, this method has a problem on the multi print-head system. Because multi-printing system has a other printing method compare with a single printing system. Therefore, we experiment a single head 3D printing and proposed a 3D printing method using a multi-piezo head.

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이중버블시트를 이용한 단열보온양생공법의 한중매스콘크리트 현장적용 (Field Application of the Mass Concrete Using Insulation Curing Method with Double Bubble Sheets Subject to Cold Weather)

  • 이동규;김종;김기훈;황인성;한민철;한천구
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2007년도 춘계학술논문 발표대회
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    • pp.1-4
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    • 2007
  • This study investigated the applicability of insulation curing method with double layer bubble sheets to the man concrete subjected to cold weather. Temperature history of the mass concrete indicated that the highest temperature of center section was exhibited at $34^{\circ}C$ while the that of surface section was $25^{\circ}C$. Difference between center and surface was shown to be less $10^{\circ}C$ when the temperature of center section was peak section, and thereby associated temperature cracking index was calculated 1.5, and occurrence probability of temperature cracking was 5%, so there was no temperature cracking caused by internal restraint. No temperature crack was observed by naked eye. It was clear that early frost demage and temperature cracking could be restrained due to reducing temperature difference between inner part and outside in the case double bubble sheets applied to insulation curing method in cold weather. The maturity of mass concrete is higher than outside about $72\sim89^{\circ}$ DD, so it was demonstrated to prevent early frost demage and ensure strength excellently. Insulation curing method with double bubble sheets was more economic than heating curing method.

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전기적 특성을 이용한 UV 경화 프로세스에 대한 새로운 평가방법 (A New Evaluation Method of UV Curing Process by Using Electrical Properties)

  • 이문학;김성빈;손세모;천재기
    • Korean Chemical Engineering Research
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    • 제43권3호
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    • pp.393-400
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    • 2005
  • 산증식제가 가지고 있는 산증식 능력을 측정하기 위한 새로운 평가 방법이 연구되어지고 있다. 그 방법은 UV 조사에 따른 산의 발생으로 인한 전도도 변화를 측정하는 것에 그 원리를 두고 있다. 본 연구자는 실험을 통해 다음과 같은 사실을 알 수 있었다. Inks film의 UV 경화반응 동안의 epoxy monomer의 광중합과 UV 경화율에 의해 전기 전도도가 감소하게 된다는 것이다. 본 논문에서는 새로운 산증식제를 합성하고, 합성된 산증식제의 열적 안정성을 DSC로 측정하였다. 여기서는 mono-type의 산증식제가 di-type의 산증식제보다 열적으로 더 안정하였다. 이러한 결과를 바탕으로 경화과정에 있어 UV 경화형 ink의 경화속도를 동적으로 평가할 수 있었다.

황색종 연초 황변기 cyclic건조가 건조엽의 물리성에 미치는 영향 (Effect of Cyclic Change of Wet Bulb Temperature During Yellowing Stage on Physical Properties of Flue-Cured Tobacco)

  • 이철환;진정의;한철수
    • 한국연초학회지
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    • 제20권1호
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    • pp.13-18
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    • 1998
  • In the flue curing process, the wet bulb temperature is usually controlled at a constant level. To improve the quality of flue cured leaves, we studied the effect of the cyclic change of wet bulb temperature at the yellowing stage of flue curing on physical properties of cured leaves. The wet bulb temperature was automatically controlled between preset high (38℃) and low point (35℃) every one hour cyclically. As a result, the acceleration of the increase in the physical properties of cured leaves were observed. The leaves cured by this method were more or less orange in color, better bodied, and less brittle compared with the leaves produced by conventional curing. However, the leaves cured by this method had a little sharpness and harshness. As to the physical properties, there was decreased in occurrence of flat leaves than that of conventional ones. On the other hand, in case of cyclic curing method, increase of price per kg reached to 2-3% compared with those of conventional ones.

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겨울철 버블시트 포설방법 변화에 따른 벽식구조 수직철근의 온도 특성 (Temperature Properties of Vertical Reinforcements in Wall Structures in Relation to the Different Methods of Bubble Sheet Installation in Winter)

  • 김태우;이제현;경영혁;이정교;한민철;한천구
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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    • pp.11-12
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    • 2017
  • This study aims to analyze the properties of the temperature change in vertical reinforcements in outdoor wall structures in winter in relation to the different methods of bubble sheet installation, and to subsequently determine the possibility of initial frost damage to the concrete as a result of low temperature. As for the experimental variables, double bubble sheets were used as curing materials, and the curing method was to model the part where the slab and the wall intersect and the rebar is exposed, and to measure the change of temperature around the exposed rebar in accordance with the change of the coating curing. It was found that by employing curing method B, which is to install the bubble sheet between the vertical reinforcements, the most vulnerable area, which is 50mm below(④) the surface of the concrete, would be lowered to sub-zero temperature 20 hours later than when using curing method A, and that therefore it is more effective to install the bubble sheet between the vertical reinforcements for the prevention of initial frost damage.

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Investigation of the effect of internal curing as a novel method for improvement of post-fire properties of high-performance concrete

  • Moein Mousavi;Habib Akbarzadeh Bengar
    • Computers and Concrete
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    • 제33권3호
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    • pp.309-324
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    • 2024
  • Internal curing, a widely used method for mitigating early-age shrinkage in concrete, also offers notable advantages for concrete durability. This paper explores the potential of internal curing by partial replacement of sand with fine lightweight aggregate for enhancing the behavior of high-performance concrete at elevated temperatures. Such a technique may prove economical and safe for the construction of skyscrapers, where explosive spalling of high-performance concrete in fire is a potential hazard. To reach this aim, the physico-mechanical features of internally cured high-strength concrete specimens, including mass loss, compressive strength, strain at peak stress, modulus of elasticity, stress-strain curve, toughness, and flexural strength, were investigated under different temperature exposures; and to predict some of these mechanical properties, a number of equations were proposed. Based on the experimental results, an advanced stress-strain model was proposed for internally cured high-performance concrete at different temperature levels, the results of which agreed well with the test data. It was observed that the replacement of 10% of sand with pre-wetted fine lightweight expanded clay aggregate (LECA) not only did not reduce the compressive strength at ambient temperature, but also prevented explosive spalling and could retain 20% of its ambient compressive strength after heating up to 800℃. It was then concluded that internal curing is an excellent method to enhance the performance of high-strength concrete at elevated temperatures.

Preparation of UV protective cotton fabrics by novel UV-curing technique - Using a photocrosslinkable polymer, poly(ethylene glycol) dimethacylate -

  • Kim, Sin-Hee
    • 패션비즈니스
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    • 제11권6호
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    • pp.52-61
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    • 2007
  • To increase the ultraviolet radiation (UVR) protection of cotton fabric, ultraviolet protection (UVP) materials were treated onto cotton fabric using a new technique, UV-curing. A photocrosslinkablepolymer, poly(ethylene glycol) dimethacrylate was used as a UV-curable resin in the presence of a small amount of photoinitiator. Two kinds of UVP materials were used, UV-absorber, 2,2'-dihydroxy-4-methoxy benzophenone, and UV-scatterer, $TiO_2/ZnO$ Pad-dry-cure method in employing these materials onto cotton was also conducted to compare the effectiveness and the washfastness of UVP treatment between curing methods. UVP treated cotton fabric showed a moderate increase in UVP in case of 2,2'-dihydroxy-4-methoxy benzophenone treatment and a high increase in case of $TiO_2/ZnO$. UV-curing method increased the washfastness of UVP property of $TiO_2/ZnO$ treated cotton fabrics. However, in case of 2,2'-dihydroxy-4-methoxy benzophenone, similar wash fastnesses of UV-cured and pad-dry-cured cotton were observed. It can be presumed that 2,2'-dihydroxy-4-methoxy benzophenone was not significantly affected by water since its hydrophobicity. In short, UV-curing of UVP materials onto cotton was successfully done, and treated cotton fabrics showed the increased UVP properties and an increased washfastness in some extent.