혼합제가 콘크리트의 내산성과 물리적성질에 미치는 영향에 관한 실험적 연구(II)

고재군 한국농공학회 1971 한국농공학회논문집 Vol.13 No.3

農村計劃을 위한 施設의 調査

高在君,金文基,奇宇奭 農科大學 農業開發硏究所 1980 農業開發硏究 報告書 Vol.1 No.1

혼화제가 콘크리트의 물리적 성질과 내산성에 미치는 영향에 관한 연구

고재군 한국농공학회 1971 한국농공학회논문집 Vol.13 No.2

모르타르의 내구성에 관한 연구

고재군 한국농공학회 1969 韓國農工學會誌 : 전원과 자원 Vol.11 No.4

이 실험(實驗)은 시멘트모르타트를 0.1N-NaOH의 알카리용액(溶液)에 침지(浸漬)시켜 alkali작용(作用)에 의한 모르타르의 부식(腐蝕)이 모르타르의 물리적(物理的) 성질(性質)에 미치는 영향을 구명(究明)하여 내고기성 모르타르 또는 콘크리트의 배합설계(配合設計)에 기초자료를 제시(提示)하고저 기도(企圖)하였던 바 이를 요약(要約)하면 다음과 같다. 가. 공시체(供試體)는 5cm입방체(立方體)의 모르타르로서 그 배합비(配合比)(중량(重量))는 1:1, 1:3, 1:5, 1:7, 1:10의 5종(種)을 만들어 사용(使用)하였다. 나. 공시체(供試體)의 물리시험(物理試驗)은 재령(材令) 7일(日), 28일(日), 3개월(個月) 6개월(個月)의 압축강도시험(壓縮强度試驗)과 5시간(時間) 자비(煮沸)의 흡수율시험(吸水率試驗)을 하였다. 다. 알카리시험(試驗)에서는 0.1N-NaOh 용액(溶液)을 사용(使用)하고 7일간격(日間隔)으로 감량(減量)을 7주간(週間) 계속(繼續) 측정(測定)하였다. 라. 알카리작용(作用)에 의(依)한 모르타르의 부식(腐蝕)은 배합비(配合比) 1:1, 1:3에서는 전연(全然) 생기지 않았고 1:5와 1:7에서 7주후(週后) 각각(各各) 3.5%와 6.26%로서 미량(微量)이였으나 1:10에서는 36.6%의 상당(相當)한 감량율(減量率)이였다. 그러나 같은 농도(濃度)의 고산용액에서는 같은 침액기간(浸液期間)(7주간(週間))을 통(通)해서 감량율(減量率)을 보면 배합비(配合比) 1:1에서 20.4% 1:3에서 25.1%, 1:5에서 56.8%, 1:7에서 72.2% 그리고 1:10에서 92.0%이므로 알카리의 작용(作用)에 의한 모르타르의 부식(腐蝕)은 산(酸)의 작용(作用)에 의한 부식(腐蝕)에 비(比)해서 극(極)히 적다는 것을 알 수 있다. 마. 보다 내고기성 모르타르를 만들기 위하여 배합비(配合比)를 1:7 또는 더 부배합(富配合)이고 흡수율(吸水率)은 5시간(時間) 자비(煮沸)하였을 때 20% 이하(以下) 밀도(密度)는 $1600kg/m^3$이상(以上) 그리고 사용수량(使用水量)은 시공연도(施工軟度)을 감안하여 수밀성(水密性)을 높이기 위하여 될 수록 소량(少量)으로서 더욱 장기양생(長期養生)이 요망(要望)되었다. 한편 내산성(耐酸性) 모르타르의 품질(品質)은 내고기성 모로타르가 되므로 콘크리트의 배합설계(配合設計)에서는 내산성(耐酸性)의 품질(品質)을 유지(維持) 또는 향상(向上)시킴으로써 알카리의 작용(作用)에 의(依)한 피해(被害)를 면(免)할 수 있다고 본다. The experiment was carried out as one of the basic studies to improve the alkali-resistance of cement mortars and it was conducted to investigate some propetties of mortars relating to weight losses when exposed to 0.1 N salution of sodium hydroxide. The experiment and the results obtained are summarized as follow; 1. The specimens used in this experiment were made of 5 centi-meter cubes of mortar having such various ratios of mix by weight as 1 : 1, 1 : 3, 1 : 5, 1 : 7 and 1 : 10. 2. Physical tests included compressive strengths at 7 days, 28 days, 3 months, and 6 month, and 5 hour boiling absorption test. 3. In alkali test, every specimen was immersed into 0.1 N solutions of sodium hydroxide. The specimens exposed to the alkali solution were weighed to determine the weight losses of the alkail-corroded at one week interval for 7 week's exposure and the old alkali solutions were also changed to fresh solutions when weighed the weight losses by alkali attack at one week interval. 4. According to the alkail test after 7 week's exposure, no weight losses were observed on ratios of mix 1:1 and 1:3 and slight weight losses occurred on ratios of mix 1:5 and 1:7, but relatively large amount of weight losses were showed by 36.6 per-cent on ratios of mix 1:10. It was also found that the weight losses of the alkali-corroded were extremely lower than those of the acid-corroded at the some concentrations as 0.1 N of solutions. 5. In order to make better quality of alkali-resistant mortar it might recomend that a 1:7 mix or richemixes, use of small amount of mixing water for watertight, 20 per cent or less absorption by 5 hour boiling 1,600 kirogram per cubic meters or denser densities by absolute dry base are available for physical properties of mortar. It could conclude acid-resistant mortars were so high alkali-resistant, that it is expected to make and improve the acid-resistant mortars for getting rid of damages by alkali attack.

Cemeso1혼화제가 콘크리트의 압축강도와 내산성에 미치는 영향에 관한 연구

고재군,황경구 한국농공학회 1975 한국농공학회논문집 Vol.17 No.2

This study was conducted to investigate some effects of Cemesol on acidresistance and compressive strength of concrete. In mix design of concrete, the cemesol was used as an admixture of cement, and it was added to the mix in an amount equal to 0.1%, 0.2%, 0.3%, and 0.4% by weight of cement of the mix. Concrete specimens were made in accordance with the. Korean Standard Specification for concrete and they were tested for acid-resistance and compressive strength at 2 weeks intervals through 8 weeks. The tests were performed in two cases non-curing and curing for 28 days. The results obtained from the tests are summarized as follows. 1. Refering to acid-resistance test, the cemesol was comparatively effective at every cemesol content except 0.3% in case of non-curing and it was found that cemesol content of 0.4% was the optimum. On the other hand, the cemesol was ineffective in case of curing, but it was seen that cemesol content of 0.1% had some effect at 6 to 8 weeks curing only. 2. Refering to compressive strength test, the cemesol was remarkably effective at a content of 0.1% but it was also shown most inefiective at content of 0.3% in case of non-curing. On the other hand the cemesol was comparatively effective at every content of cemesol except a content of 0.2% in case of curing and it was determined that the cemesol content of 0.3% may be an optimum content. 3. Since optimum cemesol content varied according to acid-resistance, compressive strength and cases such as non-curing and curing, as indicated above may be desirable to choose an optimum cemesol content suitable for purposes and ciroumstances of construction works or conditions of location. 4. The corrosive rate was proportional to compressive strength in case of non-curing, but the relation was reversed in case of curing. It was found that corrosive rate for 8 weeks did not influence compressive strength in case of non-curing but compressive strength in case of curing begins to vary under the influence of corrosion. Thus, corrosion may be more serious to compressive strength in case of curing than that in case of non-curing.

서해조수에 의한 콘크리트의 부식 방지법에 관한 연구

고재군 한국농공학회 1972 한국농공학회논문집 Vol.14 No.2

이 연구는 해수 작용에 대한 콘크리트의 내구성 시험의 일환으로 각종 배합설계에 있어서는 보통 시멘트 만을 사용, 혼화제로서 후라이애쉬, 포조리스, 빈솔레진등을 각각 보통시멘트에 사용, 포조란 시멘트만을 사용한 것등으로 구분하고 각 콘크리트의 공시체는 K. S규정에 준하여 만들어서 양생하였다. 그리고 압축강도 시험은 재령 7일, 28일 및 3개월 강도를 측정하고, 흡수율시험은 재령 28일 공시체로서 저불법(煮沸法)에 의하여 5시간 끓은 물에 당구어 흡수율을 측정 하였다. 이와같이 콘크리트의 물리적성질에 대한 시험 결과를 요약하면 다음과 같다. 1. 후라이애쉬를 혼화제로 사용한 콘크리트는 각 재령에 있어서 그 효과가 인정 되었으나 흡수율에 있어서는 보통 콘크리트와 같은 결과를 얻었으므로 그 효과는 인정할 수 없는 셈이다. 2. 포조리스를 혼화제로 사용한 콘크리트는 각 재령에 있어서 압축강도나 흡수율에 있어서 그 효과가 인정되며 후라이애쉬(강도)나 빈솔레진을 사용한 콘크리트 보다 더욱 큰 효과를 나타내었다. 3. 빈솔레진을 혼화제로 사용한 콘크리트는 각 재령에 있어서 압축강도나 흡수율에 있어서 그 효과가 인정되었다. 그러나 포조리스나 포조란시멘트를 사용한 콘크리트보다 약간 그 효과는 떨어졌다. 4. 포조란시멘트만을 사용한 콘크리트는 각 재령에 있어서 압축강도나 흡수율은 이 시험에서 가장 큰 효과를 나타내었으며 특히 장기 강도는 급증 현상을 보였다. 이 시험에서 포조란시멘트는 콘크리트의 품질개선에 있어서 바람직한 시멘트라고 생각된다. 5. 콘크리트의 압축강도와 흡수율간에는 희정기선관계가 성립 되었으나 이는 각 재령에 따라 일직하지 않고 조기재령에 비하여 장기 재령 일수록 더욱 급격한 강도의 변화율을 나타 내었다. 6. 후라이애쉬를 제외하고 포조리스나 빈솔레진을 혼화제로 사용한 콘크리트와 포조란 시멘트만을 사용한 콘크리트는 물리적 성질의 개선으로 미루어 볼 때 해수작용에 대한 내구성에 있어서도 그 효과가 기대될 것으로 본다. This study was attempted in order to search for phyosical properties on various mix designs of concrete as ne of studies relating top revention against corrosion by action of sea water in the West Sea. In this study, as concerete mix design, fly ash, pozzolith and vinsolresin were used as admixtures for normal portland cement respectively, and pozzolan cement and normal cement were also used for each plain concrete. Concrete specimens were made and cured in accordance with the Korean Standard Specifications for concrete. In thetest, compressive strengths of the specimens were measured at the following ages; 7-day, 28-days and 3-months. Absorption test was made by immersing the specimens in water kept at boiling temperature for 5 hours. The results obtained from the tests are summarized as follows; 1. The use of fly ash as an admixture in mix design of concrete, has an effect on compressive strength at each age. But it is actually not effective on absorption by concrete, as the result of the fly ash concrete is almost the same at that of ordinary plain concrete. 2. The use of pozzolith as an admixture in mix design of concrete, has an effect on both of compressive strength at each age and absorption rate. The pozzolith is more effective than vinsol resin, relating to improvement for physical proreties of concrete. 3. The use of vinsol resin as an admixture in mix design of concrete, has also an effect on both of compressive strength at each age and absorption rate. As the above fact, effectiveness of the vinsol resin is some what lower than pozzolith, as far as physical properties of the concrete are concerned. 4. Plain concrete used pozzolan cement only is the most effective on both of strength at each age and absorption rate in this study. The pozzolan cement is characteristic of higher strenth as the age is later. 5. Relationship between compreessive strengths and absorption rates of the concrete is shown by a different regression line dependingon ages. The gradient of the regression line is steeper as the age is later. 6. Throught physical test, it may be expected that the use of pozzolith and vinsol resinas asan admixture respectively will be better resistant than fly ash or ordinary plain concrete and that plain pozzolan concrete will also be the best resistant to action of sea water due to improvement of theirphysical properties.

관거의 응력해석

고재군 한국농공학회 1974 한국농공학회논문집 Vol.16 No.1

농어촌발전(農漁村發展)과 전망(展望)

고재군 한국농공학회 1990 韓國農工學會誌 : 전원과 자원 Vol.32 No.2

조수에 의한 콘크리트 침식방지법에 관한 연구(ll)

고재군 한국농공학회 1973 한국농공학회논문집 Vol.15 No.2

이 연구는 해수작용에 대한 콘크리트의 내구성시험의 일환으로 각종 배합설계의 콘크리트에 대하여 1년간 실내에서 해수에 침지하여 압축강도와 부식율을 규명하고저 시도하였다. 각종 콘크리트의 배합설계에 있어서 보통시멘트만을 사용한 것, 혼화제로서 후라이애쉬, 포조리스, 빈솔레진 등을 각각 보통시멘트에 사용한 것, 그리고 포조란 시멘트만을 사용한 것 등으로 구분하고 각 콘크리트 공시체는 K.S 규정에 준하여 만들어 재령 7일 및 28일 양생하였다. 그리고 압축강도시험은 수중과 해수에 각각 1년간 침지한 것에 대하여 강도를 측정하고 부식율시험은 해수중에 1년간 침지한 것에 대하여 부식율을 측정하였다. 이와같은 콘크리트의 압축강도시험과 부식율 시험에 대한 결과를 요약하면 다음과 같다. (1) 압축강도에 있어서 보통콘크리트는 수중이나 해수중에 다 같이 다른 콘크리트의 강도보다 낮으므로 포조란시멘트나 혼화제인 후라이애쉬, 포조리스. 빈솔레진은 각각 그 효과가 인정되었다. (2) 포조란시멘트는 수중에서 강도가 다른 콘크리트보다 가장 높았으나 해수중에서는 후라이애쉬보다 낮은 강도를 나타내었다. 따라서 포조란시멘트는 해수중에서 보다 수중에서 강도상 효과가 있다는 것을 알 수 있다. (3) 후라이애쉬는 수중에서와 해수중에서 다 같이 장기강도에 있어서 높은 강도를 갖인 특성이 있다는 것을 나타내었고, 수중에서는 포조란시멘트에 비하여 강도가 낮었으나 해수중에서는 오히려 포조란 시멘트의 강도를 능가하고 있어 해수중에서는 포조란 시멘트보다 강도상 더욱 그 효과가 크다는 것을 알 수 있다. (4) 포조리스는 후라이애쉬와 포조란시멘트에 비해서 그 효과가 떨어지나 빈솔레진에 비해서는 강도상에 있어서 항상 그 효과가 인정되공 있다. (5) 빈솔레진은 포조란시멘트나 혼화제중에서 강도상 가장 그 효과가 낮으나 보통콘크리트에 비하면 그 효과는 수중이나 해수중에서 다 같이 인정되고 있다. (6) 콘크리트의 압축강와 흡수율과의 관계는 후라이애쉬를 제외하면 다른 재령에서와 같이 흡수율이 적을수록 압축강도는 증가되며 회기직선관계가 성립되었다. 그러나 후라이애쉬는 장기강도에서 그 특징이 현저히 나타나고 있어 다른 콘크리트의 흡수율에 비하여 현저히 높은 강도를 나타내고 있다. (7) 부식율에 있어서는 1년간 해수작용을 받었을 때 각 콘크리트의 유의적인 부식율이 인정될 수 없으며 외관상에서도 부식현상을 식별할 수 없었다. This study was carried out to investigate the effects of various mix designs of concrete on the compressive strengths and corrosive rates when the concretes were immersed in sea water of the West Sea, as the part of study related to durated to durability of concrete by action of the sea water. Concrete mix designs used in this study were ordinary Concrete mix, Concrete mixes with different admixtures such as fly ash, pozzolith and vinsol resin, and pozzolan concrete mix. The concrete specimens were made and cured for 7 days and 28 days in the fresh water in accordance with the Korean Standard specification for concrete. Compressive strengths of the specimens were measured after immersing the specimens for one year in fresh water and sea water which were placed indoors. The sea water used in this test was taken from the Bay of Ahsan. Corrosive rate was also tested after immersing the specimens in the same sea water and placed indoors for one year. The results obtained from the tests are summarized as follows; 1. Compressive strength of an ordinary concrete was the lowest of the various mix desings of concrete immersed both in the fresh water and the sea water. Therefore, the uses of pozzolan cement, fly ash, pozoolith and vinsol resin in mix design of concrete had and effect on increasing compressive strength. 2. Pozzolan concrete was the most effective on compressive strength in the fresh water, but it had less effect than concrete with fly ash admixture immersed in the sea water. 3. The use of fly ash admixture in mix design of concrete showed higher strength as the immersing age is longer both in fresh water and sea water than the other concretes besides pozzolan concrete, but the concretewith fly ash admixture had lower strength than pozzolan concrete in the sea water. Therefore, concrete with fly ash admixture might be better than the pozzolan concrete as far as durability of concrete to sea water was concerned. 4. The use of pozzolith admixture in mix design of concrete had less compressive strength than the use of pozzolan cement for fly ash admixture both in fresh water and sea water. However, the concrete with pozzolith admixture was much stronger than one with vinsol resin admixture in fresh water, but somewhat stronger in the sea water. 5. Though the use of vinsol resin admixture was more effective than ordinary concrete on compressive strength both in fresh water and sea water, it was the least compressive strength among the other concretes. 6. Relation between compressive strengths and absorption rates of every kind of concrete besides concrete with fly ash admixture showed a linear regression line and the compressive strength is highee as the absorption rate is lower. Concrete with fly ash admixture had extremely high strength in comparison with corresponding adsorption rates of the other concretes. 7. Corrosive appearance on the surface of concretes was not occured significantly when exposed to the sea water for one year, However, the specimens of concretes besides ordinary concrete were a little heavier than those cured in fresh water for 28 days.

Cemesol混和劑가 콘크리트의 壓縮强度와 耐酸性에 미치는 影響에 關한 硏究

高在君 서울대학교 1975 서울대학교 論文集 Vol.25 No.-

This study was conducted to investigate some effects of cemesol on acid­resistance and compressive strength of concrete. In mix design of concrete, the cemesol was used as an admixture of cement, and it was added to the mix in an amount equal to 0.1%, 0.2%, 0.3%, and 0.4% by weight of cement of mix. Concrete specimens were made in accordance with the Korean Standard Specification for concrete and they were tested for acid­resistance and compressive strength at 2 weeks intervals through 8 weeks. The tests were performed in two cases such as non­curing and curing for 28 days. The results obtained from the tests are summarized as follows. 1. Refering to acid­resistance test, the cemesol was comparatively effective at every cemesol content except 0.3% in case of non­curing and it was found that cemesol content of 0.4% is most optimum. On the other hand, the cemesol was ineffective in case of curing, but it was seen that cemesol content of 0.1% is some effective at 6 weeks to 8 weeks only. 2. Refering to compressive strength test, the cemesol was remarkably effective at a content of 0.1%, but it was also shown most ineffective at content of 0.3% in case of non­curing. On the other hand, the cemesol was comparatively effective at every content of cemesol except a content of 0.2% in case of curing and it was determined that the cemesol content of 0.3% is an optimum content. 3. As results from the tests, since optimun cemesol content varied depending upon acid­resistance, compressive strength and cases such as non­curing and curing, it is desirable to choose an optimum cemesol content suitable for purposes and circumstances of construction works or conditions of location. 4. Relationship between corrosive rate and compressive strength was proportional in case of non­curing, but inversely proportional in case of curing. It was found that corrosive rate for 8 weeks does not influence compressive strength in case of non­curing but compressive strength in case of curing begins to vary under the influence of corrosion is more serious to compressive strength in case of curing than that in case of non­curing.