• 콘크리트학회논문집
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• 제12권3호
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• pp.3-10
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• 2000

In this study, we compared a plain mortar with the CAS-system shrinkage compensation mortar for Ondol that is Korean traditional heating system. The Ondol mortar is necessary to have properties as non-crack, fine flatness and stability for thermal changes. especially, mortar'crack prevention is to be most important property in Ondol mortar. To develope the stable material on the crack-prevention, we used to calcium-sulfo-aluminate(CSA)system in shrinkage compensation mortar. And so, we confirmed the effects of calcium-sulfo-aluminate(CSA) system for mortar's physical properties such as setting time, compressive strength and expansion ratio for crack prevention. The initial and final setting time of the CSA mortar is faster than plain mortar about 2hours. And, Compressive strength increased about 20% that plain mortar. The crack length per unit area, plain mortar is 0.426∼0.481m/m2. The Results of apartment construction field test, the shrinkage compensation mortar is excellent about the crack-reduce effect.

• 공업화학
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• 제10권3호
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• pp.486-490
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• 1999

타일을 부착시키는 tile 전용 cement mortar가 갖추어야 하는 물성인 우수한 보수성, 작업성, open time, 처짐저항성과 타임접착강도 등을 향상시키기 위해 본 연구에서는 mortar에 첨가하는 혼화제들의 홉합비율을 달리하였을 때 나타나는 특성을 비교 분석하였다. Mortar의 보수성 효과를 주는 hydroxypropylmethylcellulose에 소량의 합성 starch을 첨가해 줌으로써 mortar는 보수성을 유지하면서 겉마름이 적게되었고, open time이 길어져 작업성이 향상되었다. 타일의 접착강도를 높이기 위해 polyacrylamide와 ethylenevinyl acetate을 첨가하여 mortar 자체 및 타일의 처짐을 줄였고, 바탕면과 타일과의 mortar 접착력을 증대시켰다. 이와 함께 melment의 첨가로 mortar에 유동성을 주어 작업성을 향상시켰다. 이들 첨가제의 필요량은 cement량에 대해 hydroxypropyl methylcellulose는 0.80~1.20%, starch 0.10~0.15%, polyacrylamide 0.001~0.015%, ethylenevinyl acetate 0.05~0.10% 및 melment 0.003~0.005%의 혼합비율일 때 tile cement mortar의 물성이 향상됨을 알 수 있었다.

• 한국세라믹학회지
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• 제12권4호
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• pp.9-18
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• 1975

Polymer emulsion was used as the admixture for the purpose of increasing the mechanical properties of cement mortar. The effect of polymer emulsion admixture on compressive strength and tensile strength and chemical resistance, relative humidity on compressive and tensile strength, sand particles on water absorption were studied. The results were as follows. 1. Polymer emulson modified mortar cured under 95% of realative humidity showed lower strength than the mortar cured at dry condition. 2. The maximum strength was attained at 10~20% of polystyrene and polyacrylic acid ester polymer-cement mortar. 3. The modified mortar (sand size rate (-9＋35)mech:(-35＋60)mech=4 : 1) was 1.5 times lower than the modified mortar (1 : 1) in water absorption. 4. Compared with the ordinary mortar, the modified mortar showed 2~3 times greater chemical resistance for 5% HCl or 5% H2SO4.

• 한국안전학회지
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• 제19권2호
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• pp.104-111
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• 2004

The aim of this study was to investigate the influence of inorganic pigments on the physical properties of cement mortar. For this purpose, the compressive strength and absorption test were carried out on cement mortar imxed with inorganic pigments by changing the proportion of cement mortar, water-cement ratio, and ratio of pigment. The result of this study can be summarized as follows: the compressive strength of colored mortar rapidely increased in red and yellow mortar, as the mix ratio of pigment increased. In case of green and black mortar, however, the compressive strength decresed as the mix ratio incresed. In case of red and yellow mortar, the absorption of colored mortar increased as the mixing ratio increased, if the mean particle diameter of the pigment is small. In case of green and black mortar, the absorption ratio decreased as the mix ratio increased. After investigating the overall physical properties of colored mortar, it was confirmed that the proper mix ratio of pigment securing the properties of colored mortar was below 6% of the weight of the cement to be used.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.392-397
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• 1998

In this paper, the properties of cement mortar used recycled aggregate are analyzed and compared with river and crushed sand mortar. Recycled aggregates are made by crushing wasted concrete had various compressive strength, and test items are the properties of fresh mortar, hardened mortar and durability. According to the experimental results, flow, unitweight, strength and durability of cement mortar used recycled aggregates decrease compared with those of river and crushed sand mortar.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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• pp.1133-1138
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• 2000

The interface necessarily exists in joints using cement mortar, UP(Unsaturated Polyester : UP) mortar and SBR(SBR-latex) mortar. Characteristics of shear transfer in joint interface consisting of different materials are studied with experimental and analytical methods. The uniaxial compressive shear experiments are accomplished with various angle of inclination (35, 45, 55, 65, 75°), materials of old and new-cast mortar. In this study, The results are as follows ① Mohr-coulomb's slip theory be applied to the interface consisting different materials ② The cohesion of UP mortar is superior to that f cement mortar, SBR mortar.

• 한국세라믹학회지
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• 제27권7호
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• pp.833-840
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• 1990

For the development of multi-functional materials which has water reducing power, air entraining power and waterproofing power as well as blending additive in cement mortar the coal ash was modified with asphalt-stearic acid or asphalt-boiled oil mixtures by mechanical treatment. And the physical properties of cement mortar blended with modified coal ashes were compared with those of the water-tightness-cement mortar and the ordinary-portland-cement mortar added with AE.water reducing agent. The mortar of coalash-blend-cement modified with asphalt-stearic mixture was increased acid about 20% in initial strengths and decreased about 20% in water absorption ratio than those of ordinary coalash-blend-cement. The mortar of coalash-blend-cement modified with asphalt-bolied oil mixture was similar to the cement mortar added with AE.water reducing agent in water reduction ratio, air entraining conents and the initial strengths, also was similar to the water-tightness-cement mortar in water absorption and water permeability ratios.

• Computers and Concrete
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• 제3권5호
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• pp.357-373
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• 2006

The concepts of four parameters of nominal water-cement ratio, equivalent water-cement ratio, average paste thickness, fly ash-binder ratio were introduced. It was verified that the four parameters and the mix proportion of mortar can be transformed each other. The behaviors (strength, workability, et al.) of mortar primarily determined by the mix proportion of mortar now depend on the four parameters. The prediction models of strength and workability of mortar were built based on artificial neural networks (ANNs). The calculation models of average paste thickness and equivalent water-cement ratio of mortar can be obtained by the reversal deduction of the two prediction models, respectively. A mortar mix proportion design algorithm was proposed. The proposed mortar mix proportion design algorithm is expected to reduce the number of trial and error, save cost, laborers and time.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.525-526
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• 2009

본 논문에서는 Sporosarcina pasteurii라는 미생물의 생체광물형성작용을 이용하여 Calcite($CaCO_3$) 석출을 유도하고, 이를 Mortar에 적용하여 요구 성능 향상을 평가하였다. Sporosarcina pasteurii를 혼입(input)한 Mortar 시험체(C3S-S.p)와 일반 Mortar 시험체(C3S-W)의 중성화 반응을 실험을 통해 비교한 결과 C3S-S.p가 C3S-W에 비해 중성화가 지연되는 것을 육안으로 확인할 수 있었다. 또한 28日간 Urea-CaCl2 수용액(Medium)에서 양생한 C3S-S.p와 C3S-W의 내구성을 실험을 통해 비교한 결과 Sporosarcina pasteurii를 혼입한 Mortar 시험체(C3S-S.p)가 일반 Mortar 시험체(C3S-W) 비해 내구성이 향상된 것으로 나타났다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2005년도 추계 학술논문 발표대회
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• pp.39-42
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• 2005

This study investigates influence of organic fiber reinforced materials, affecting crack reduction of cement mortar using low grade natural sand(LNS). According to the test, for the properties of fresh mortar, the mortar using natural sand(NS) exhibited that flow value increased until adding most of fiber less than 1$\%$, except for Polyvinly alchol fiber(PVA), and then it decreased. Meanwhile, the mortar mixed with LNS showed that increase of fiber content decrease flow value, regardless of fiber type. Air content increased in the mortar adding nylon fiber(NY) and polypropylene fiber(PP), while it maintained or decreased in the mortar adding cellulose fiber(CL) and PVA. Compressive strength of the mortar does not affect during early age, but mortar using NS and adding 0.1$\%$ of fiber content increased the value, except for PP, at 28 age days, while the mortar mixed with LNS decreased. For the properties of tensile strength, mortar, using NS and adding individually PP and PVA, exhibited higher value. Especially 0.1$\%$ of NY provided the highest value. In addition, the mortar mixed with LNS resulted in improved tensile value as fiber content increased. It is demonstrated that mortar using LNS led to higher length change ratio than natural sand.