• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.5
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• pp.128-135
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• 2010

Polymer-modified cement mortar(PCM) has been widely used for strengthening of the concrete structures due to its excellent physical properties such as high strength and durability. Adhesive strength or behavior, on the other hands, between PCM and concrete is very important in strengthening the concrete member using PCM. Therefore the adhesive failure mechanism between PCM and concrete should be fully verified and understood. This study was performed to evaluate adhesive strength of PCM to the concrete by the direct pull-out test. In the direct pull-out tests, the adhesive strength under the various pre-treatment conditions such as immersion, thunder shower, freezing and thawing are evaluated. Also, the field direct pull-out test are performed to investigate the adhesive strength of mock-up test specimens. In the results of the test, the adhesive strength value by field test are lower than those of the standard curing condition. From these comparison and investigation, field test result was similar with the thunder shower test result. The results of the test was used to evaluate the korean industrial standard of polymer modified cement mortars for maintenance in concrete.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.1
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• pp.71-84
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• 1992

Polymer-Impregnated Concrete(PIC) is a composite material of concrete and polymer. PIC has superior properties compared to conventional cement concrete, such as strength, stiffness, toughness, durability, water-proofing, chemical resistance. However, the usage of PIC has been limited to repairing materials and non-structural applications due to the lack of the design criteria and the analytical model to determine structural behavior. The objective of this study is experimentally to develop the optimum mixing proportions of polymer impregnants and the stress-strain responses, the strength characteristics, the fatigue and creep behaviors, and the durabilities of MMA(methyl methacrylate)-based PIC.

• Cement
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• s.192
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• pp.39-47
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• 2011

최근 온실가스 감축과 기후변화 그리고 녹색성장에 대한 관심증대와 더불어 시멘트 분야의 연구 생산분야는 천연자원 사용량을 줄이고, 소성공정을 도입하지 않은 새로운 개념의 무기바인더가 다시 고개를 들고 있다. 다른 용어로는 비소성, 무시멘트 등으로 표현되기도 하는데, 광의의 개념으로 보면 알칼리 활성화제를 사용한 비소성 무기결합재인 지오폴리머가 바로 그것이다. 지오폴리머 결합재는 1957년 우크라이나의 토목공학회에서 개발한 알칼리 활성 슬래그시멘트에 기원을 두고 있고, 1970년대 말 프랑스의 다비도비치에 의해 지오폴리머라는 용어가 처음 사용되기 시작했다. 알칼리 활성 무기결합재(Alkali-activated inorganic binder)의 정의이다. Alkali-activated inorganic binder는 원래는 결합능력이 없던 재료에 대해서 Alkali-activating 용액을 첨가했을 때, 시멘트처럼 결합능력을 가지게 되는 모든 종류의 결합시스템을 말한다. 국내에도 이미 2000년 초부터 지오폴리머의 개념을 도입한 제품이 상업화되어 오랫동안 품질검증을 거쳐 안정성이 확인되고 있다. 최근에 다시 전남대가 그 동안의 연구성과를 발 빠르게 중소기업에 기술 이전하여 소위 무시멘트 시대에 진입하는 분위기이다. 지난 9월 동아에스텍(주)과 조인트벤처 설립을 위해 손을 잡았고, 사업화가 곧 진행될 것으로 보인다. 이를 계기로 국내에도 무시멘트회사가 본격적으로 등장하게 된 것이다. 따라서 본 고는 무시멘트의 개념을 잘 표현한 문헌으로 일본콘크리트공학 연차논문집, 2010년 1월호를 번역 요약 발췌한 것이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.247-249
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• 2013

열화한 철근콘크리트 구조물에 대하여 성능회복을 위하여 전기화학적 방식, 단면복구공법, 균열보수공법, 표면마감공법 등이 상용되고 있다. 본 연구에서는 단면복구공법의 적용과 성능예측을 위한 해석 모델의 입력값으로 사용될 보강철근과 단면복구재의 부착특성을 평가하기 위하여 철근인발실험을 실시하였다. 폴리머시멘트몰탈이 사용되었으며 부착요소의 강성과 강도를 구하여 비선형 해석을 실시하여 상당한 정확도의 예측값을 도출하였다.

• Korean Journal of Agricultural Science
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• v.25 no.1
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• pp.89-96
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• 1998

This study was performed to evaluate the engineering properties of permeable polymer concrete with rice-husk ash. The following conclusions were drawn; 1. The highest sterngth was achieved by 50% filled rice husk-ash permeable polymer concrete, it was increased 24% by compresseve, 123% by tensile and 90% by bending strength than that of the normal cement concrete, respectively. 2. The static modulus of elasticity was in the range of $1.27{\times}10^5{\sim}1.75{\times}10^5kgf/cm^2$, which was approximately 58~70% of the normal cement concrete. The higher elastic modulus was showed by 50% filled rice-husk ash permeable polymer concrete, relatively. The poisson's number of permeable polymer concrete was less than that of the normal cement concrete. 3. The ultrasonic pulse velocity was in the range of 2,503~3,083m/sec, which was showed about the same compared to that of the normal cement concrete. The higher pulse velocity was showed by 50% filled rice-husk ash permeable polymer concrete. 4. The water permeability was in the range of $4.612{\sim}5.913{\ell}/cm^2/hr$, and it was largely dependent upon the mix design. These concrete can be used to the structures which need water permeability.

• Journal of the Korea Concrete Institute
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• v.17 no.3 s.87
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• pp.411-418
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• 2005

Polymer-modified mortar and concrete are prepared by mixing either a polymer or monomer in a dispersed, or liquid form with fresh cement mortar and concrete mixtures, and subsequently curing, and if necessary, the monomer contained in the mortar or concrete is polymerized in situ. Although polymers and monomers in any form such as latexes, water-soluble polymers, liquid resins, and monomers are used in cement composites such as mortar and concrete, it is very important that both cement hydration and polymer phase formation proceed well the yield a monolithic matrix phase with a network structure in which the hydrated cement phase and polymer phase interpenetrate. In the polymer-modified mortar and concrete structures, aggregates are bound by such a co-matrix phase, resulting in the superior properties of polymer-modified mortar and concrete compared to conventional mortar and concrete. The purpose of this study is to obtain the necessary basic data to develope appropriate latexes as cement modifiers, and to clarify the effects of the monomer ratios and amount of emulsifier on the properties of the polymer-modified mortars using methyl methacrylate-butyl acrylate(MMA/BA) and methyl methacrylate-ethyl acrylate(MMA/EA) latexes. The results of this study are as follows, the water absorption, chloride ion penetration depth and carbonation depth of MMA/BA-modified mortar are lowest. However, they are greatly affected by the polymer-cement ratio rather than the bound MMA content and type of polymer.

• Journal of the Korea Concrete Institute
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• v.17 no.5 s.89
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• pp.703-708
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• 2005

The effects of polymer-cement ratio and antifoamer content on the setting time and durability of high-fluidity polymer-modified mortars using redispersible polymer powder are examined. As the result, the setting time of the polymer-modified mortars using redispersible polymer powder tends to be delayed with increasing polymer-cement ratio, regardless of the antifoamer content. The water absorption, chloride ion penetration depth and carbonation depth of the high-fluidity polymer-modified mortars using redispersible polymer powder decrease with increasing polymer-cement ratio and antifoamer content. The resistance of freezing and thawing and chemicals improvement is attributed to the improved bond between cement hydrates and aggregates because of the incorporation of redispersible polymer powder

• Cement
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• s.140
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• pp.16-21
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• 1995

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.3
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• pp.89-96
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• 2013

Now-a-days, a manhole adopted since the late 1990s and produced using the polymer concrete has widely used due to the various benefits. While entering the High oil prices times, however, and with the price increase of the petrochemical materials, the cost of manufacture of polymer concrete was elevated and the resulting polymer concrete's weakness is being put on. Accordingly, the development of economic cement concrete manholes, which can replace the outstanding bending strength of manhole made of high-price polymer concrete, has been required. In this study, based on the cement technology of fast hardening armorphous calcium aluminate (ACA), by minimizing the amount of cement using the industrial byproducts, to develop the eco-friendly high-toughness concrete manhole, which can reduce $CO_2$ reduction, was intended. As the results, the cement concrete manhole, which economic, eco-friend, and meeting the performance requirements, was developed.

• Journal of the Korea Concrete Institute
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• v.19 no.4
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• pp.457-465
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• 2007

In this paper, polymer-modified repair materials using polymer dispersions with six repair methods are prepared with various polymer-cement ratios, and tested for compressive and flexural strengths through each curing condition such as dry cure, water cure, and freezing and thawing cyclic action. And, the adhesive interface between the polymer-modified mortar and mortar substrate is observed by a scanning electron microscope. From the test results, the compressive and flexural strengths of cement mortar repaired by polymer-modified mortar are improved with a rise in the polymer-cement ratio regardless of the type of polymer and curing conditions. Such an improvement in the strengths of polymer-modified repair materials to ordinary cement mortar is explained by the high adhesion of polymer-modified mortar. Strength reduction of polymer-modified repair materials after freezing and thawing cyclic actions is recognized, but it is lower than that of unmodified mortar. Especially, cement mortar repaired by polymer-modified mortar with a St/BA emulsion has good strength properties compared with those of SBR latex and PA emulsion. Accordingly, it is judged that polymer-modified mortars with a St/BA emulsion are possible to use as repair materials to ordinary cement mortar and concrete.