• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.421-424
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• 2003

The purpose of this study is to clarify the effect of the emulsifier ratio on strength properties of the polymer-modified mortars using methylmethacrylate-ethyl acrylate(MMA/EA) latexes, and to obtain basic data necessary to develope appropriate latexes for cement modifiers. Polymer-modified mortars using MMA/EA latexes are prepared with various monomer ratios, and tested for air content, flexural and compressive strengths. From the test results, we knew that the water-cement ratio is decreased and the air content is increased with an increase in the amount of emulsifier. In general, the superior flexural and compressive strengths of polymer-modified mortars using MMA/EA latexes is obtained at a bound MMA content of 60 percent and a emulsifier ratio of 6 percent.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.425-428
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• 2003

This study deals with the mechanical properties of polymethyl methacrylate(PMMA) mortars without crosslinking agent. Waste expanded polystyrene(EPS) is used as a multifunctional admixture such as a thickener, a extender, a shrinkage reducing agent, a assistant to polymerization. PMMA mortars are prepared with various EPS contents of binder and subjected to a dry and a dry/heat combined curing, and tested for working life, flexural and compressive strengths. From the test results, the working life of PMMA mortars without crosslinking agent is shortened with raising EPS content of binder. The flexural and compressive strengths of the PMMA Mortars are decreased somewhat with increase in the EPS content. PMMA mortars with good mechanical properties could be manufactured without any crosslinking agent and their properties would be controled by adjusting EPS content of binder.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.449-452
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• 2003

The objective of this study is to investigate the basic properties of polyester mortars using ground calcium carbonate(GCC), blast furance slag(BFS), fly ash(FA), ordinary portland cement(OPC) as fillers. Particle size distribution, particle shape and resin absorption of GCC, BFS, FA and OPC are checked. Polyester mortars with GCC, BFS, FA and OPC are prepared with various MEKPO content and tested for working life. The flexural and compressive strengths of the polyester mortars with MEKPO content of 0.5phr are evaluated. As a test result, the average sizes of GCC, BFS, FA and OPC are 9.7$\mu\textrm{m}$, 11.6$\mu\textrm{m}$, 21.2$\mu\textrm{m}$, 29.9$\mu\textrm{m}$. Resin absorption of FA is 1.5times larger than other fillers. The polyester mortar with FA at a MEKPO content of 0.5phr has the longest working life and the maximum flexural and compressive strengths.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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• pp.357-362
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• 1997

The purpose of this study is to evaluate the adhesion of concrete pipe lining using polymer mortar. The polymer mortars with various mix proportions are prepared, and tested for flexural and compressive strengths, adhesion in tension, and the aspects of lining surface and workability are evaluated. Form the test results, it is apparent that the appropriate polymer mortars of lining to concrete pipe can be produced. The flexural and compressive strengths of polymer mortar for lining are affected by type of resin, and aggregates content, and water content at the surface of concrete pipe is important factor for improvement in adhesion of polymer mortar. It is obvious that the economical polymer mortars having an excellent cost performance ration can be produced through this study.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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• pp.375-380
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• 1997

The purpose of this study is to examine the properties of polymer-modified mortars using asphalt emulsion. The polymer-modified mortars using asphalt emulsion with various asphalt-cement ratios are prepared, and tested for flexural and compressive strengths, water absorption and permeability, carbonation, Cl ion penetration and chemical resistance. From the test results, the flexural and compressive strengths, water absorption and permeability, carbonation and Cl ion penetration depths of polymer-modified mortars using asphalt emulsion tend to be decreased with increasing asphalt-cement ratio, and chemical resistance is improved. It is evident that polymer-modified mortars using asphalt emulsion having an excellent properties as a waterproof and finish materials can be produced.

• 한국안전학회지
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• 제32권5호
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• pp.69-75
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• 2017

Structural safety evaluation for static strength of thin plate RC member with high strength concrete is conducted in this study. Static strengths were predicted and compared with the experimental values. Predicted values were calculated by the evaluation formula based on the punching shear behavior and the yield line theory which can appear in the plate members. Static load tests were carried out for the specimens with high strength concrete and the test results were compared with the required performance in design. The comparison results show that the specimens with high strength concrete have sufficient structural safety for flexural and punching shear performance required in design. High strength concrete specimens exhibited excellent strength despite their small thickness. The range of concrete strengths applied in this study was about 60 MPa to 100 MPa.

• 한국농공학회지
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• 제41권1호
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• pp.97-105
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• 1999

Recently , polymer concrete has been widely used in the construction industry because of its quick setting, high strength, excellect adhesion, watertightness and chemical resistance compared to ordinary cement concrete. Its application is also increased. In this paper, lightweight polymer mortars using unsaturated polyester resin and lightweight aggregate are prepared with various mix proportations, and tested for slump working life, apparent specific gravity , flexural and compressive strengths. As a result, the slump and working life can be controlled and thier flexural and compressive strengths are 9.7 to 22.0 MPa , and 23.0 to 100.8 MPa respectively at apparent specific gravities of 0.86 to 1.73.

• Elastomers and Composites
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• 제50권3호
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• pp.205-209
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• 2015

Magnesium oxide (MgO) reinforced polyamide-66 (PA66) composites were prepared through melt-compounding method in order to determine the possibility of using MgO particle as conductive filler in the polymer-based composite. The effects of MgO filler content on the thermal conductivity and mechanical properties for the PA66/MgO composites were investigated. The results showed that the addition of MgO filler to the PA66 matrix led to a large increase in thermal conductivity of the PA66/MgO composites. Tensile strengths of the PA66/MgO composites were slightly decreased as MgO filler loading increased. However, flexural strength and flexural modulus were improved with increasing filler loading. Notched Izod impact strengths were dramatically lowered by the addition of MgO filler.

• Elastomers and Composites
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• 제55권1호
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• pp.1-5
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• 2020

This study examined the effects of the addition of maleic anhydride-grafted polypropylene (PP-g-MA) and polyolefin elastomer (POE) on polyamide 66 (PA66) and polypropylene (PP) blends. The blends of PA66/PP with PP-g-MA and POE were prepared using a twin screw extruder. Mechanical testing results revealed that the tensile, flexural, and izod impact strengths of the blends were maximized at a PP-g-MA content of 2 phr. The increased mechanical strength of the blends with PP-g-MA was attributed to the compatibilizing effect of the PA66 and PP blends. In addition, as the POE content increased, the impact strength of the blends increased. However, at a high POE content, the tensile and flexural strengths decreased, seemingly because of the lower mechanical properties of POE.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.727-730
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• 2004

The purpose of this study is to evaluate the fundamental properties of fine type cement grouts with redispersible polymer powders. Cement grouts with redispersible polymer powders are prepared with various polymer-cement ratios, and tested. for flow, water absorption, drying shrinkage, flexural and compressive strengths. From the test results, flow of the cement grouts with EVA and Va/VeoVa polymer powers decreased with increasing elapsed time. Regardless of polymer type, the flexural strength of the cement grouts tends to increase with increase in polymer-cement ratio. The maximum compressive strengths of the cement grouts are obtained at a polymer-cement ratio of $5\%$.