• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.811-815
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• 2003

The effects of high-range water-reducing agent (WRA) content and polymer-cement ratio on the strength properties of autoclaved SBR-modified mortars with WRA are examined. As a result, the flexural strength of the autoclaved SBR-modified mortars with WRAs tends to increase with increasing WRA content and polymer-cement ratio, and reaches a maximum at a WRA content of 2.0%. The compressive strength of the autoclaved SBR-modified mortars with WRAs is inclined to increase with increasing WRA content and polymer-cement ratio, and reaches a maximum at a WRA content of 2.0% and a polymer-cement ratio of 10%. From the test results, the addition of the WRAs is effective for improving strength properties of the autoclaved SBR-modified mortars.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.71-72
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• 2022

In this paper, the performance evaluation of the vibration damping ratio according to the polymer mixing ratio of the polymer modified mortar used as the floor finishing material of the apartment building structure was evaluated. To compare the vibration damping rate, ordinary potland cement (OPC) mortar and polymer modified mortar (PMM) were prepared. In addition, the mixed polymer was mixed with Styrene Butadiene Rubber (SBR) liquid polymer with a solid content of about 49%. Accordingly, the W/C of the test specimen was adjusted and compounded, and the experiment was conducted by mixing 5 types of the test specimen: OPC-60, PMM-5%, PMM-10%, PMM-15%, and PMM-20%. In addition, in order to adjust the W/C of the specimen, the fluidity of each specimen was set as 210 (±5) mm. The specimens measured density and flow in fresh mortar and after curing for 28 days, flexural strength, compressive strength and ultrasonic pulse were measured. The attenuation rate was shown. The experimental results showed that the density increased according to the mixing of the polymer, the flexural strength increased as the mixing rate of the polymer increased, and the compressive strength was decreased. In addition, it was shown that the vibration damping rate increases with the increase in the amount of polymer incorporated.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.2
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• pp.124-134
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• 2013

This study investigated the effect of surface water on concrete substrate on adhesive strength in tension of very high flowable SBR-modified cement mortar. The specimens were prepared with proportionally mixing SBR latex, ordinary portland cement, silica sand, superplasticizer and viscosity enhancing agent. Polymer cement ratio (P/C) were 10, 20, 30, 50 and 75% and the weight ratio of fine aggregate to cement were 1:1 and 1:3. The specimens obtained with different P/C and C:F were characterized by unit weight, flow test, crack resistance and adhesion test. After basic tests, two mixtures of P/C=20% and 30% in case of C:F=1:1, and one mixture of P/C=50% in case of C:F=1:3 were selected, respectively. These three selected specimens were studied about the effect of surface water evenly sprayed on concrete substrate by a amount of 0, 0.006, 0.012, 0.017, 0.024g per unit area ($cm^2$) of concrete substrate surface The results show that surface water on concrete substrate increases the adhesive strength in tension of high flowable SBR-modified cement mortar and improve the flowability compared to the non-sprayed case.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.1005-1010
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• 2001

Recently, polymer-modified mortar has been studied for proposed use on industrial floors as top layers with thin thicknesses, typically 5~ 15mm. The purpose of this study is to evaluate basic properties of self leveling materials using polymer modifier as kinds of SBR, PAE, SUBA. Superplasticizer and thickener have been included in the mixes to reduce bleeding and drying shrinkage as well as in order to facilitate the workability required. The self leveling materials using four types of polymer dispersion are prepared with polymer-cement ratios which respectively range from 50%, 75%, and were tested for basic characteristics such as adhesion in tension, crack resistance test, rebound test after the preparative tests for unit weight, air content, consistency ratio etc. The results show almost as equal quality as existing commercial industrial flooring when mortar is modified by polymer dispersion. Adhesion in tension of polymer modified mortars using each SBR and PAE emulsion was over 10 kgf/$cm^{2}$. Crack or flaw derived from shrinkage is strongly dependent on the type of polymer dispersion because of each different total solid of polymer. It is judged that polymer modified mortar with self-leveling can be very well suited for Floor-finished.

• Journal of the Korea Institute of Building Construction
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• v.22 no.6
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• pp.543-551
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• 2022

The mechanical performance and vibration damping ratio performance of a specimen according to the polymer mixing rate were evaluated for polymer modified mortar. As a polymer, Styrene Butadiene Rubber(SBR) liquid polymer with a solid content of about 49~51% was used, and the polymer content was increased by liquid 5%. The specimen was 40*40*160(mm), and after curing, compressive strength, flexural strength, and vibration damping ratio were measured using the ultrasonic pulse method. As a result, it was found that the compressive strength decreased as the polymer was mixed, but the flexural strength was increased. The vibration damping ratio increased by 11% at 5% polymer, 28% at 10% polymer, 33% at 15% polymer, and 72 at 20% polymer. I was found that the incorporation of the polymer was very effective to reduce the vibration of the mortar. In addition, through SEM and SEM-EDS analysis, it is determined that the cause of vibration reduction due to polymer mixing is that the polymer film formed in the transition zone of aggregate and internal voids buffered the vibration of the mortar inside. Taken together, in the scope of this study, the appropriate polymer mixing ratio for reducing the vibration of mortar is judged to be about 7.5%.

• Polymer(Korea)
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• v.32 no.6
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• pp.555-560
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• 2008

Polymer-modified mortars have been largely used as paving materials, flooring, waterproofing material, adhesives, anticorrosive linings, deck coverings, and other various materials. The various types and properties of the mixed polymer largely affect the characteristics of polymer-modified mortar that has been mixed with polymer latexes. Consequently, its application purposes are varied according to these properties. This paper investigates the typical properties of polymer-modified mortars that contain styrene and butyl acrylate latexes and styrene butadiene rubber. They are then tested to obtain air contents, water-cement ratios, flexural and compressive strengths, water absorption, and chloride-ion penetration. From the test results, the superior flexural strength of polymer-modified mortars is obtained at a S/BA-2 and a polymer-cement ratio of 20%. And, the water absorption and chloride ion penetration depth are greatly affected by the polymer-cement ratio rather than the types of polymer. 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.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.1011-1016
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• 2001

The purpose of this study is to find out the effect of polymer glass transition temperature on mechanical properties of polymer latex-modified mortars in comparison with ordinary cement mortar. The Polymer latex-modified mortars are prepared with 5, 10, 15 and 20% of polymer cement ratio respectively, and properties of modified mortars such as air content, compressive, flexural and tensile strengths are tested. The test results indicate that the types of polymer dispersion and the polymer-cement ratio are very important factors to characterize the properties of polymer-modified mortars, and also the glass transition temperature of polymer dispersions has an important effect on the performance of polymer-modified mortars. The modifying effects of two kinds of polymer dispersion, St/BA-1 and SBR, are evaluated.

• Computers and Concrete
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• v.12 no.5
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• pp.651-668
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• 2013

Concrete structures need repairing due to various reasons such as deteriorative effects, overloading, poor quality of workmanship and design failures. Cement based repair mortars are the most widely used solutions for concrete repair applications. Various factors may affect the bond strength between concrete substrate and repair mortars. In this paper, the effects of polymer additives, strength of the concrete substrate, surface roughness, surface wetness and aging on the bond between concrete substrate and repair mortar has been investigated. Full factorial experimental design is employed to investigate the main and interaction effects of these factors on the bond strength. Analysis of variance (ANOVA) under design of experiments (DOE) in Minitab 14 Statistical Software is used for the analysis. Results showed that the interaction bond strength is higher when the application surface is wet and strength of the concrete substrate is comparatively high. According to the results obtained from the analysis, the most effective repair mortar additive in terms of bonding efficiency was styrene butadiene rubber (SBR) within the investigated polymers and test conditions. This bonding ability improvement can be attributed to the self-flowing ability, high flexural strength and comparatively low air content of SBR modified repair mortars. On the other hand, styrene acrylate rubber (SAR) modified mortars was found incompatible with the concrete substrate.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.63-66
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• 2008

Not only mechanical properties, bonding properties, electro chemical properties, etc. but also fire safety is required in patch repair materials such as polymer modified cement mortar (PCM) which are used to deteriorated reinforced concrete structure. Unfortunately, it is very difficult to choice the appropriate repair materials because there are not enough information about fire safety properties of PCM. In this study, The combustion characters of PCM were evaluated through the heat release rate test and non-combustibility test. The pyrogenicity test uses the cone calorimeter based on the oxygen consumption method. The non-combustibility test is from the temperature change inside the furnace during the test. The effect of the types of polymer and polymer content were evaluated from the series of test. The results are like followings. 1) The higher the W/C of PCM, the lower the gross calorific value and heat generation rate in the heat release rate test. The amount of heat generation of PCM is like the order of VVA, EVA, and SBR in this study. 2) Some materials such as E45-100, E50-100, E60-100, S50-50, and S50-100 were estimated as not appropriate building materials in the non combustibility test.

• KCI Concrete Journal
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• v.13 no.2
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• pp.58-66
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• 2001

Recently, polymer-modified mortar has been studied for proposed use on industrial floors as top coat with thin thickness, typically 5~15mm. The purpose of this study is to evaluate basic properties of self-leveling materials using polymer dispersions as kinds of SBR, PAE, St/BA with thin coat (under 3mm). Superplasticizer and thickener have been included in the mixes to reduce bleeding and drying shrinkage as well as to facilitate the workability required. The self-leveling materials using four types of polymer dispersion are prepared with polymer-cement ratio which respectively range from 50% and 75%, and tested for basic characteristics such as unit weight, air content, flow, consistency change and adhesion in tension. From the test results, the self-leveling materials using PAE emulsion at curing age of 28days are almost equal to those of conventional floor using urethane and epoxy resin. The adhesion in tension of self-leveling mortars using SBR latex and PAE emulsion at curing age of 3days is over 17 kgf/cm$^2$(1.67MPa). Consistency change is strongly dependent on the type of polymer dispersion. It is concluded that the self-leveling materials using polymer dispersions can be used in the same manner as conventional floor using thermosetting resin in practical applications, in the selection of polymer dispersions.