• Title/Summary/Keyword: Premixed cement

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A finishing construction method for concrete floor and slab using the cement based self leveling mortar (시멘트계 SL재를 사용한 콘크리트슬래브 미장공법)

  • 손형호;이종열
    • Proceedings of the Korea Concrete Institute Conference
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    • 1994.10a
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    • pp.387-392
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    • 1994
  • Recently, as the problems according to lack of skilled labour and superior construction materials were gathering strength, there were required the advent of a special materials in building construction division. As a view of the point, the cement-based Self leveling mortar was developed for improvements of the former problems. The Self leveling mortar has the all kinds of the properties as followed the premixed products in plant, self-smoofhing, non shrinkgae etc, accordingly the finishing of concrete floor don't need skilled labour. The purpose of this study is to establish the introduction of a finishing construction method for concrete floor and slab using the cement-based self leveling mortar. Presented is a study on the basic properties of fresh and hardened self leveling mortar. To this end, an actual floor's finishing construction using the cement-based self leveling mortar was conducted in approximately 1,800㎡ floor as to compare the flatness and levelness after finighing.

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Freeze-thaw of Durability for Premixed Fly Ash Concrete (프리믹스 플라이애시 콘크리트 동결-융해 특성)

  • Hong, Seung-Ho;Han, Seung-Hwan;Lee, Byung-Duk
    • Proceedings of the Korea Concrete Institute Conference
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    • 2009.05a
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    • pp.261-262
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    • 2009
  • The prevent methods of Alkali-Silica Reaction (ASR) are studying after the failure cases by ASR were reported in Korea. In this study, the freeze-thaw test and scaling test for premixed fly ash cement were performed. The ratio of fly ash and cement is 20 percent and 80 percent by weight of total cementious material. The results show that the dynamic modulus after 300 cycles the freeze-thaw test for most of specimen except the specimen have less 3% air was more than 90 % and the loss of weigh the specimen after 50 cycles scaling test was less than 1kg/$m^3$.

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Equations Evaluation for and Shear Behavior Characteristics of Joint according to Cement Composite Types (시멘트 복합체 종류에 따른 접합부의 전단거동 및 산정식 평가)

  • Jeon, Esther;Yun, Hyun-Do;Lee, Young-Oh;Kim, Sun-Woo;Ryu, Seung-Hyun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.97-98
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    • 2010
  • This paper discusses shear behavior of Joint with premix mortar and strain hardening cement composites(SHCC) with PVA and PE fibers. The main variables considered include the type of cement composites(premixed mortar, SHCC with hybrid fiber) and reinforcement. It was evaluated that shear load had a good accordance with the test and equation result.

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Evaluation of Setting Time, Solubility, and Compressive Strength of Four Calcium Silicate-Based Cements (네 가지 규산 칼슘계 시멘트의 경화시간, 용해도, 압축강도 평가)

  • Yuji Jang;Yujin Kim;Junghwan Lee;Jongsoo Kim;Joonhaeng Lee;Mi Ran Han;Jongbin Kim;Jisun Shin
    • Journal of the korean academy of Pediatric Dentistry
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    • v.50 no.2
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    • pp.217-228
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    • 2023
  • This study aimed to compare the physical properties of 4 kinds of calcium silicate-based cements (CSCs): 2 kinds of powder-liquid mix type (RetroMTA® [RTMX] and Endocem® MTA Zr [EZMX]) and 2 kinds of premixed type (Well-RootTMPT [WRPR] and Endocem® MTA premixed [ECPR]) CSCs, respectively. Further, we assessed the setting times, solubility values, and compressive strengths of the cements. The shortest setting time was observed for EZMX (123.33 ± 5.77 seconds), followed by RTMX (146.67 ± 5.77 seconds), ECPR (260.00 ± 17.32 seconds), and WRPR (460.00 ± 17.32 seconds), respectively. The highest solubility was observed for WRPR (9.01 ± 0.55%), followed by RTMX (2.17 ± 0.07%), EZMX (0.55 ± 0.03%), and ECPR (0.17 ± 0.03%). Furthermore, the highest compressive strength was observed for ECPR (76.67 ± 25.67 Mpa), followed by WRPR (38.39 ± 7.25 Mpa), RTMX (35.07 ± 5.34 Mpa), and EZMX (4.07 ± 0.60 Mpa). In conclusion, the premixed type CSCs (WRPR and ECPR) exhibited longer setting times compared to the powder-liquid mix type CSCs (EZMX and RTMX). The solubility test showed that ECPR had the lowest solubility while WRPR had the highest solubility, with a statistically significant difference between them (p < 0.0083). Additionally, the compressive strength test showed that ECPR had the highest compressive strength, while EZMX had the lowest compressive strength, also with a statistically significant difference between them (p < 0.0083). ECPR is a promising material as it is premixed, eliminating the need for mixing time, and it has also demonstrated improved solubility and compressive strength, making it a potentially favorable option for clinical use.

The Performance and Application of Repair System for the Exterior Wall According to the Durability Improvement in the RC Structure(Part2:Summary of Inorganic Repair System) (내구성향상을 고려한 R.C조 외벽보수시스템의 성능과 그 활용(제2보:무기질계 보수공 법 개요))

  • Kwon, Young-Jin;Kim, Chul-Ho;Kwak, Young-Jun;Park, Deuk-Kon;Choi, Long
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.10a
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    • pp.139-144
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    • 1995
  • It is the aim of this study to introduce the performance and application of new repair system for the exterior wall by durability failure caused seasand especially. The elementary performance of this repair system is as follows (1)All the layer in the repair are cement based, same with the mother conrete (2)this repair system use SBR admixture (3)This cement and mortar powder for this repair system are premixed and ready to use just adding admixture at the job site.

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The New Repair System of R.C Structure caused by carbonation and salt damage (중성화 및 염해를 입은 콘크리트구조물의 보수시공기술)

  • Kwon, Young-Jin;Kim, Chul-Ho;Jang, Tea-Min;Park, Deuk-Kon;Choi, Long
    • Proceedings of the Korea Concrete Institute Conference
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    • 1996.04a
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    • pp.414-417
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    • 1996
  • It is the aim of this study to introduce the performance and application of new repair system for the exterior wall by durability failure caused carbonation and salt damage. The elementary performance of this repair system is as follows. (1) Al the layer in the repair are cement based, same with the mother concrete (2) this repair system use SBR admixture (3) This cement and mortar powder for this repair system are premixed and ready to use just adding admixture at the job site.

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Fundamental Characteristics the Concrete According to Mixing Methods and Unit Water Content of Ternary Blended Cement (3성분계 시멘트의 단위수량 및 혼합방식에 따른 콘크리트의 기초특성)

  • Lee, Il-Sun;Hong, Seak-Min;Baek, Dae-Hyun;Kim, ki-hoon;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2009.11a
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    • pp.133-136
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    • 2009
  • This study analyzes the mixing and basic characteristics of concrete according to the unit quantity and mixing method of ternary blended cement and the results of this study can be summarized as follows. In the case of the premixed cement (hereafter referred as POBF) of POBF135, it satisfies the target level of fluidity and air content in which it shows relatively small bleedings even though it represents the latest initial and final setting. Also, although the POBF135 represents small initial strength, it shows an increase in the strength according to the increase in aging. In addition, it shows the lowest temperature in the POBF135. As a result, it can be seen that the POBF135 indicates the most optimal mixing subject to considering the aspect of fluidity, compressive strength, and heat of hydration in general figures.

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The Effects of the Coplymerization Conditions in Synthesis of Polycarboxylic Type Superplasticizer on Interfacial Properties and on Cement Mortar Fluidity (Polycarboxylate계 콘크리트 유동화제의 합성에 있어서 공중합 조건에 따른 계면물성 변화 및 이의 시멘트 몰탈의 물성에 미치는 영향)

  • Kim, Young-Ho
    • Applied Chemistry for Engineering
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    • v.21 no.4
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    • pp.463-468
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    • 2010
  • The polycarboxylic (PC) type concrete superplasticizer was synthesized. The effects of ethylene oxide group number and its molecular weight on the properties of the polycarboxylic type concrete superplasticizer and the concrete motar properties were studied. To investigated of the interfacial properties of the premixed-concrete with the superplasticizer, the type and the amount of polyethylene glycol, meta acrylate added, and type of the initialization agent were studied. Also the interfacial properties of the superplasticizer aqueous phase, the wettability on the cement particle, the fluidity of the cement mortar, and the strength properties of the concrete were measured. For a high fluidity of the cement mortar and a high strength of concrete, a low value of the surface tension and contact angle were required for PC. To have a good performance for PC, the reaction condition of 1.3 mol ratio of MA against to MPEG was suitable with KSP initiator.

Evaluation of the Basic Properties of Materials for Application of Functional Plaster Mortar (기능성 미장 모르타르의 현장 적용을 위한 재료별 기초 물성에 관한 평가)

  • Cho, Do-Young;Kim, Gyu-Yong;Miyauchi, Hiroyuki
    • Journal of the Korea Institute of Building Construction
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    • v.12 no.2
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    • pp.152-160
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    • 2012
  • The development of building must be accompanied with construction technology and performance of materials. In particular, wet processes have a high level of dependence on manpower and a low level of diversification of materials used. This study aimed to determine the applicability of various materials for wet process, mechanized construction and eco-friendly building materials through a comparison with dry premixed mortar. As a result, it was found that resin plaster and gypsum plaster's strength is lower than that of dry cement mortar, but their mechanization application, construction simplification, smoothness and bond strength are higher than that of dry cement mortar. And estimate that is valid as workability, bonding strength, eco-friendly building material in occasion of gypsum plaster.