• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.667-675
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• 2006

Concrete is much more easily damaged by various parameters than by the only one and performance reducing mechanism grows more complicated in that condition. In addition, the factors which really act in concrete structure tend to be activated in turn and the degradation of concrete is very rapidly progressed. The purpose of this study is to evaluate the properties of polymer cement mortars under combined cures. The polymer cement mortars are prepared with various polymer types, polymer-cement ratios and cement-fine aggregate ratio, and tested for compressive and flexural strengths, accelerated carbonation, chloride ion penetration and acid resistance test, and freezing-thawing test. The properties of polymer cement mortars under combined cures is discussed. From the test results, polymer cement mortars have superior strengths compared with plain cement mortar under combined cures. The strengths of polymer cement mortars are markedly increased at curing condition II and V, however strengths are not improved at curing condition I and IV irregardless of polymer types. The carbonation and chloride ion penetration depths of polymer cement mortars tend to decrease in curing conditions, III-C, IV-B, V-A order, and decrease with increasing polymer cement ratios. It is concluded that polymer cement ratio of 10 to 15% are considered optimum for the preparation of such polymer cement mortars.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.1
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• pp.51-60
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• 2006

This study was conducted to investigate experimentally the drying shrinkage and the strength properties of redispersible SBR and PAE powder-modified mortars. Polymer-cement ratio, content of shrinkage-reducing agent and antifoamer content were manipulated as the experimental variables. The peculiarity of this study is to obtain a high early-age strength by using the portland cement and alumina cement with the ratio of 8 : 2. Until 7 days of age, the drying shrinkage remarkably increased up to $1\~2\times10^{-4}$, while it tended to decrease as the ratio of polymer to cement ratio and the content of shrinkage-reducing agent increased. Polymer-cement ratio was effective in improving the flexural, tensile and adhesive strengths: As the ratio increased, the strengths correspondingly increased. The flexural strength was in the range of $7\~11$ MPa, the tensile strength was $3.5\~5$ MPa and the adhesive strength was $1.2\~3.9$ MPa. On the other hand, the compressive strength tended to decrease as the polymer-cement ratio increased, and it was in the range of $23\~39$ MPa. All strengths, flexural, tensile, adhesive and compressive strengths, decreased as the content of powder shrinkage-reducing agent increased. It turned out that the polymer-cement ratio influenced more on the behavior of drying shrinkage and the properties of strength than the powder shrinkage-reducing agent did.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.200-201
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• 2018

The purpose of this study is to evaluate the adhesion in tension of polymer-modified mortars according to curing conditions. From the test results, the adhesion in tension is seriously affected by type of curing conditions compared with type of polymer dispersions or polymer-cement ratios. The maximum adhesion in tension of EVA-modified mortar with polymer-cement ratio of 20% cured by standard condition is about 1.81 times, the cement mortar cured in water. It is apparent that the adhesion in tension of polymer-modified mortars according to raising of polymer-cement ratio is also much more improved irrespective of type of polymer dispersions and curing conditions.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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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 $5\%$.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.123-128
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• 2001

The Purpose of this study is to clarify the effect of the monomer ratio on properties of the polymer-modified mortars using methyl methacrylate-butyl acrylate latexes, and to obtain basic data necessary to develop appropriate latexes for cement modifiers. This paper deals with the effect of the monomer ratio on the typical properties of polymer-modified mortars with methyl methacrylate-butyl acrylate latexes. The polymer latex-modified mortars are prepared with 5, 10, IS and 20% of polymer cement ratio respectively, and properties of modified mortars such as water absorption, compressive and flexural strengths, chloride-ion penetration depth are tested. The test results indicate that the monomer ratio is very important factors to characterize the strength properties of polymer-modified mortars, but the water absorption and chloride-ion penetration depth are influenced by polymer-cement ratio rather than monomer ratios.

• Polymer(Korea)
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• v.37 no.2
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• pp.148-155
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• 2013

The purpose of this study is to clarify the effect of the emulsifier ratio on the properties of the polymer cement mortars based on styrene-butyl acrylate (S/BA) latexes, and to obtain necessary basic data to develop appropriate latexes for cement modifiers. The polymer dispersions for cement modifiers was synthesized using styrene and butyl acrylate. Polymer cement mortars based on S/BA latexes were prepared with various monomer and emulsifier ratios, and their water-cement ratio, air content, flexural and compressive strengths, water absorption and chloride ion penetration were tested. From the test results, the maximum flexural and compressive strengths of polymer cement mortars based on S/BA latexes were obtained at a bound styrene content of 60% and an emulsifier ratio of 6%. Also, the water absorption and chloride ion penetration depth are greatly affected by the polymer-cement ratio rather than the bound styrene and emulsifier content. Accordingly, it is judged that S/BA latexes can be used place of the conventional polymer dispersions of cement modifier.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.691-694
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• 2004

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 a result, the setting time of the polymer-modified mortars using redispersible polymer powder tend to delayed with increasing polymer-cement ratio, regardless of the antifoamer content. The water absorption and chloride ion penetration depth of the high-fluidity polymer-modified mortars using redispersible polymer powder decrease with increasing polymer-cement ratio and antifoamer content. The water absorption and chloride ion penetration improvement is attributed to the improved bond between cement hydrates and aggregates because of the incorporation of redispersible polymer powder.

• Journal of the Korea Institute of Building Construction
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• v.4 no.3
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• pp.93-100
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• 2004

In recent years, it has widely been studied on the light-weight composites for the purpose of the large space and thermal insulation of building structures. The purpose of this study is to evaluate the properties of light-weight composites made by binders as cement, resin and polymer cement slurry. The concrete composites are prepared with various conditions such as polymer-cement ratio, void-filling ratio, type of resin, filler content and light-weight aggregate content, tested for thermal conductivity. From the test results, the thermal conductivity of concrete composites with the binder of cement tends to decrease with increasing polymer-cement ratio, and to increase with increasing void-filling ratio. The thermal conductivity of concrete composites with the binder of resin are markedly affected by the light-weight aggregate content, type of resin and filler content. The composites made by polymer-modified concrete and polymer cement slurry have a good thermal insulation property. From the this study, we can recommend the proper mix proportions for thermal insulation Panel or concrete. Expecially. the thermal conductivity of concrete composites made by polyurethane resin is almost the same as that of the conventional expanded polystyrene resin.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.10a
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• pp.89-92
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• 1995

For the development of lilght weight cement concrete with high durability, this study used perlite and paper sludge ash by the light weight material, and polypropylene fiber by the reinforcment, and poly-acrylic ester emulsion by the matrix improvement. According to the increasing mixture ratio of fiber and use of polymer, the light weight polypropylene fiber reinforced polymer cement ratio of fiber and use of polymer, the light weight polypropylene fiber reinforced polymer cement concrete were showed high resistance for frost damage.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.437-440
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• 2005

The effects of polymer-cement ratio and recycled aggregate content on the continuous void ratio, coefficient of permeablity, compressvie, tensile and flexural strengths of water-permeable polymer-modified concretes using recycled aggregate are examined. As a result, the continuous void ratio and coefficient of permeablity of the water-permeable polymer-modified concretes tend to decrease with increasing polymer-binder ratio. Regardless of the recycled aggregate content, the compressvie, tensile and flexural strengths of the water-permeable polymer-modified concretes wtend to increase with increasing polymer-cement ratio.