• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.112-113
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• 2021

Since natural sand is being depleted, research is being conducted to use glass similar to sand as an aggregate. When non-reusable waste glass is crushed and used as fine aggregate, it is known that alkali of cement and silica of glass react to cause an alkali aggregate reaction. The purpose of this study is to provide basic data by studying the strength according to color to use waste glass as fine aggregate. When 10% was replaced, both flexural and compressive strength showed strength values similar to those of Plain. When replaced by 20% and 30%, the 7-day intensity was higher than that of Plain. In addition, colorless glass was found to have the highest strength among glass colors. More research is expected to be needed to become a fine aggregate of waste glass.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.105-106
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• 2023

Using the limestone powder as material that can alternate the clinker, it seems to get positive effect as filler and enhance workability of cement, but the amount of replacement can affect compressive strength of cement. This study was evaluated the effect of limestone mixed cement fineness and SO₃ content on cement mortar. As a result of measuring the compressive strength, it showed 93% compared to the compressive strength of Plain 28 days at fineness 4,400 and SO₃ 2.6%. It is judged that additional research is necessary to express the strength equivalent to that of Plain.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.81-82
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• 2011

This paper is to compare and analyze WOE created by emulsifying waste oil & WOES added by stimulant with the existing SR in order to solve the problem of strength and reduction in fluidity occurring in time of the use of waste oil to reduce the autogenous shrinkage of high strength mortar. As experimental results, in case of WOE, there almost never happened a drop in fluidity at 1% replacement and compressive strength also showed the strength value similar to Plain. On the other hand, the effect of strength improvement consequent upon the use of stimulant was found to be insufficient. The change of autogenous shrinkage generally showed a better reduction effect in shrinkage comparing to Plain. In case of WOE1, reduction effect in autogenous shrinkage was found to be more excellent than the existing SR. Accordingly, WOE1 is analyzed to be desirable if reduction in autogenous shrinkage, strength & up to the aspect of fluidity are taken into consideration.

• Journal of the Korea Institute of Building Construction
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• v.5 no.4 s.18
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• pp.115-120
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• 2005

In recent years, polymer-modified mortars using polymer dispersions have been widely used as finish and repair materials in the construction industry because of their excellent properties compares to those of ordinary cement mortar. Especially, the adhesion improvement of ordinary cement mortar and concrete has attracted a great deal of attention from researchers, and several unique and simply applicable techniques for the adhesion improvement have been developed. The purpose of this study is to evaluate the abrasion resistance of polymer-modified mortar according various curing methods. The polymer-modified mortar are prepared with various polymer-cement ratios, and are subjected to three curing methods such as dry rure, standard cure and freezing and thawing cure after two curing methods, and then tested for abrasion. From the test results, the polymer-modified mortars with various polymer-cement ratios have some superior abrasion resistance compared with plain mortar. The abrasion resistance of polymer-modified mortars increase with an increase in the polymer-cement ratio, and is better under water cure than any other curing methods. It is concluded that the abrasion resistance of cement mortar is markedly improved by modifying of polymer dispersion.

• Magazine of the Korea Concrete Institute
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• v.7 no.3
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• pp.156-163
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• 1995

In the previous study, styrene mdleic dnhydride copolymer(SMA) as synthesized flom styrene and rnale~c dnhydr~de and further redcted with sulfuric acid to obtam water soluble SMA. In thls study, the flow dnd strcngth tests of cement mortar rmxed wth copolymers wele carried out to evaluate the capability of copolymers as high range water reducer for the con crete. It was found from flow exper~ment that the fluidity of cenient mortar rmxed wth sulfonated SMA(SSMAj was larger thdn that mxed ulth amnophenol substituted SSMA (SmSMAj. The decreasing rate of the flow of cement mortar rmxed ulth SSMA and SmSMA was significantly lower than that mixed ulth naphthalene condensate(NSC) The compressslve strength of the hardened cement mortars containing 0.5% copolymers after 28 dys curing was exarmned. 'The compressive strength of hdrdened cement mortar containing SSMA and SmSMA was mcreased up to 31% and 13%, respectively, when omp pared to the plain. As the results, the copolyniers(SSMA and SrnSMA) used in thls study are greatly expected as a good high range water reducers for the concrete.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.6
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• pp.40-45
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• 2016

It should be noted that the use of the lathe scrap for making fiber reinforced cementitious composites raised friendly environmental effect as well as economy because the lathe scrap is a by-product of steel manefactures and is occurred when lathe and milling works of them are conducted to process steel manufactures. Thus, the purpose of this experimental research is to investigate workability and strength characteristics of lathe scrap reinforced cementitious composites(LSRCCs). For this purpose, three types of lathe scraps were collected from processing plants of metal, and then LSRCCs containing these were made for 2mm width and 40mm length. As a result, it was observed from the test results that the workability of LSRCCs was slightly decreased than plain mortar and the flexural strength of LSRCCs were much larger than these of plain mortar and effect of types of lathe scrap on the characteristics of LSRCCs were somewhat large.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.134-135
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• 2015

This study analysed compressive strength and the expansion characteristic to utilize a high volume mineral admixture mortar for a aerated mortar and a plastering mortar. In this experiment, the result shows that the compressive strength gain was satisfactory in case that WR was replaced within 5%. Also, the difference between WR1 and WR was insignificant. It shows that the drying shringkage properties at large was showed being satisfactory generally compared with Plain when WR was replaced, but the effect was not significant.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.245-246
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• 2011

In recent research in this emerging and latent heat storage material features an innovative temperature - controlled Phase Change Materials to evaluate the superior thermal performance would like to calculate the thermal conductivity. Specified in KS F 4040 test specimen dimensions were equivalent in specifications, test methods according to KS L 9016 was an experiment in progress. As a result, the thermal conductivity of plain cement mortar mixed with more PCM came out with low thermal conductivity of mortar, thermal performance was excellent.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.1267-1272
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• 2000

When fresh concrete is exposed to low temperature, the concrete may suffer frost damage due to freezing at early ages and strength development may be delayed. These are problems on cold weather concrete. One of the solution methods for resolving these problems has been to reduce the freezing temperature of concrete by the use of chemical admixtures called Accelerators for freezing resistance. Therefore, in this study, we executed freezing temperature of mortar, setting and strength properties with using water reducing accelerator and accelerators for freezing resistance which are producted internationally. As a result of this experiment, the freezing temperature of mortar is lower and the setting property is promoted when the admixing content of accelerators for freezing resistance is increased. Moreover, the compressive strength of mortar used accelerators for freezing resistance represented the result which is similar with result of analysis of compressive strength increase with using logistic curve formula, but in the case of plain and using water reducing accelerator, there is no relation between logistic curve formula, maturity and compressive strength.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.162-163
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• 2019

The purpose of this study is to evaluate the adhesion in flexure of SBR-modified mortar adding Fly Ash(FA). From the test results, the adhesion in flexure is seriously affected by polymer-binder ratios and adding content of FA. The maximum adhesion in flexure of SBR- modified mortar is about 1.46 times, the plain cement mortar. It is apparent that the adhesion in flexure of SBR-modified mortars by polymer-binder ratios is much more improved than that by adding contents of AF.