高强度콘크리트의 品質變化 特性에 미치는 시멘트 및 高性能AE減水劑의 影響에 關한 實驗的 硏究

최경렬 충남대학교 대학원 2002 국내석사

건설생산현장용 순환골재 콘크리트의 공학적 특성 평가 및 실용화에 관한 연구

최경렬 충남대학교 대학원 2007 국내박사

In recent year, it is urgently required to recycle and reuse the construction and demolition waste concrete because its amount is greatly increased according to the rapid increase of urban redevelopment project in domestic. On the other hand, demand and supply unbalance of the aggregate for construction industries has been a real problem already that we have to solve immediately, because the restriction on use and development of sea sand and a stony mountain was intensified by the related regulation. Therefore, it is necessary that recycled aggregate made from demolition waste concrete be used as new aggregate for construction industry, to decrease the waste and to accomplish the continuous construction project without failure. Also the government establish the policies and laws to promote use of recycled aggregate, and propose the quality standard of recycled aggregate. However technical development on the production technology of high-quality recycled aggregate is not systematic. And the major problem is that studies on the engineering properties and durability of concrete using recycled aggregate are insufficient. Therefore, in this study, properties of fresh and hardened concrete, long-term stability, and durability of concrete made with recycled fine and coarse aggregate were investigated experimentally. So, finally, base data for practical use of concrete made with recycled aggregate in construction field were presented. To evaluate the engineering properties of concrete made with recycled aggregate and to present the basic data of practical utilization for construction field application, this thesis was consisted of contents as follows ; The 1st chapter is the introduction of the study which presents the background, the social concern and necessities about the use of recycled aggregate and recycled concrete, and target, content and scope of this study. In the 2nd chapter, the present state of demand and supply of aggregate, construction and demolition waste concrete, the related laws and regulations, manufacturing technique and properties of recycled aggregate and recycled concrete was described. In the 3rd chapter, as the study on the effect of the quality and replacement ratio of the recycled fine aggregate on flowability and strength property of recycled mortar, compressive strength and flow of mortar made with the recycled fine aggregate were investigated according to the quality level and replacement ratio of the recycled fine aggregate. In the 4th chapter, as investigating fresh and hardened properties such as air content, slump, setting time, compressive and tensile strength, and durability such as carbonation and salt attack according to replacement ratio, water cement ratio and unit water content, the effect of replacement ratio of the recycled fine aggregate and mixing design factors on engineering properties of concrete made with the recycled fine aggregate was evaluated finally. In the 5th chapter, to evaluate the engineering properties and durability of concrete made with the recycled fine aggregate according to the quality of it, quality of it as an experimental factor was set up 3 degrees. After that, fresh properties, hardened properties and durability of the concrete made with the recycled fine aggregate were experimentally investigated. In the 6th chapter, as the experimental study on engineering properties, resistance to combined deterioration and long-term stability of recycled concrete according to quality of recycled coarse aggregate, it is experimentally investigated and analyzed each fresh and hardened properties, durability, resistance to combined deterioration and long-term stability of recycled concrete made with recycled coarse aggregate. In the 7th chapter, the synthetic conclusions of a study on the engineering properties evaluation and practical utilization of recycled concrete for construction field application were presented. In this thesis, as the purpose of study is to evaluate the engineering properties of concrete made with recycled aggregate and to present the basic data of practical utilization for construction field application, its results are summarized as the follows ; 1) Flowability and strength property of recycled fine aggregate mortar according to quality and replacement ratio of recycled fine aggregate As a results of the study on flowability and strength property of recycled fine aggregate mortar according to quality and replacement ratio of recycled fine aggregate, flow and compressive strength of mortar made with high quality recycled fine aggregate were similar to it of mortar made with natural fine aggregate. So possibility that high quality recycled fine aggregate could be applied to concrete aggregate was verified. 2) Evaluation of effect of replacement ratio of the recycled fine aggregate and mixing design factors on engineering properties of concrete It was found that effect of the recycled fine aggregate on physical properties of concrete was little, but the more replacement ratio of it was increased, the more decreased a little workability and durability were. Accordingly it was considered that the replacement range of it should be reflected in durability design. The more replacement ratio of the recycled fine aggregate was increased, the more increased carbonation depth and chloride ion penetration depth of recycled fine aggregate concrete were. And the more water-cement ratio and unit water content were decreased, the more increased resistance to carbonation and salt attack were. Especially it was confirmed that water-cement ratio is the largest factor effecting on durability in mixing design. 3) Evaluation of engineering properties and durability of concrete according to quality of the recycled fine aggregate The validity of the recycled fine aggregate was verified, as fresh and hardened properties of concrete made with it were similar to those of concrete made with natural fine aggregate. But durabilities such as carbonation and salt attack of concrete made with it were inferior to those of concrete made with natural fine aggregate. So it was though that technical development should be conducted to promote the practical use of recycled aggregate concrete for construction field. 4) Evaluation of engineering properties, resistance to combined deterioration and long-term stability of concrete made with the recycled coarse aggregate As various fresh and hardened properties of concrete made with the high quality recycled coarse aggregate were similar to those of concrete made with the natural coarse aggregate, workability and physical properties of recycled aggregate concrete were evaluated and verified experimentally. Also, in scope of this study, carbonation, salt attack, combined deterioration, length change ratio and creep deformation of concrete made with the high quality recycled coarse aggregate were similar to those of concrete made with the natural coarse aggregate. So possibility in insuring durability and long-term stability of concrete made with the high quality recycled coarse aggregate was confirmed. In this study, it was verified that workability and physical properties of concrete mede with high quality recycled aggregate was available. Hereafter, it was considered that continuant study on development technology of durability should be conducted to promote the recycled aggregate concrete for construction field.

활성슬러지 공정과 응집 공정에 의한 하수 처리 시 용존 유기물의 제거 특성에 미치는 SRT의 영향

최경렬 인하대학교 일반대학원 2006 국내석사

『靑城雜記』 硏究

최경렬 成均館大學校 2002 국내석사

1985년 한국에서 발생한 Scrub typhus 환자의 임상역학적 조사

최경렬 고려대학교 대학원 1987 국내박사

경골 골절에 대한 임상적 고찰

최경렬 경희대학교 대학원 의학과 정형외과학전공 1980 국내석사

On a linear representation of the Chevalley groups of type g2

최경렬 서울대학교 대학원 1996 국내박사

'公共選擇論의 豫算決定理論'에 關한 硏究 : W. Niskanen의 <豫算極大化模型>을 中心으로

최경렬 成均館大學校 1989 국내석사

韓國人 乳齒硬度에 關한 實驗的 硏究

최경열 경희대학교 1974 국내석사