• Title/Summary/Keyword: Recycled Coarse Aggregate

Search Result 277, Processing Time 0.024 seconds

An Experimental Study on the Fundamental Properties of Electric Pole Recycled Aggregate(EPRA) and Characteristics of High Strength Concrete by Replacement Ratios of EPRA (폐전주 재생골재의 기초물성 및 대체율에 따른 고강도영역 재생골재 콘크리트의 특성에 관한 실험적 연구)

  • 이강우;이종호;강석표;최세진;최희용;김무한
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2001.05a
    • /
    • pp.495-500
    • /
    • 2001
  • In this study, it was analized and examined fundamental properties of Electric Pole Recycled Aggregate(EPRA) and hardened properties & chemical resistance with H$_2$SO$_4$by replacement ratios of EPRA, and the results are as follows 1) In the case of electric pole recycled coarse aggregate, All fundamental properties are better than that of normal recycled aggregate and both water absorption and amount of crushed loss are with level of natural aggregate 2) As the replacement ratio of electric pole recycled fine aggregate is increased strength development is decreased. but in the case of coarse aggregate, that of it is with level of natural aggregate 3) As the replacement ratio of electric pole recycled fine aggregate is increased chemical resistance is decreased. but in the case of coarse aggregate, that of it is with level of natural aggregate

  • PDF

A Study on the Compressive Strength Property of Mortar with Fly Ash Using Water Eluted from Recycled Coarse Aggregates (용출수를 사용한 플라이애쉬 혼입 모르타르의 강도특성에 관한 연구)

  • Shin, Sang-Yeop;Jeong, Euy-Chang;Kim, Young-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2013.05a
    • /
    • pp.31-32
    • /
    • 2013
  • ThThe purpose of this study is to investigate the compressive strength properties of fly ash using water eluted from recycled coarse aggregate. When fly ash come into contact with water, they have not a autonomously chemical reaction. But fly ash is a pozzolan reaction when fly ash come into contact with water and calcium hydroxide(Ca(OH)2) in alkaline environment. For that reason, if water eluted from recycled coarse aggregate use mixture water, fly ash is expected to reaction of pozzolan reaction property in early stage. According to the experimentation result, ICP-MS analysis showed water eluted from recycled coarse aggregate has a high alkali-ash value of pH of 12 and over. And mixing ratio 30% fly ash mortar using water eluted from recycled coarse aggregate showed a similar strength of plain mortar due to the pozzolan reaction. Also, poor strength in initial age, disadvantage of mortar using fly ash, can be improved as hydration in early age is expedited due to calcium hydroxide(Ca(OH)2) and unhydrated cement component eluted from recycled aggregate mortar.

  • PDF

Evaluation on the Mechanical Performance of Low-Quality Recycled Aggregate Through Interface Enhancement Between Cement Matrix and Coarse Aggregate by Surface Modification Technology

  • Choi, Heesup;Choi, Hyeonggil;Lim, Myungkwan;Inoue, Masumi;Kitagaki, Ryoma;Noguchi, Takafumi
    • International Journal of Concrete Structures and Materials
    • /
    • v.10 no.1
    • /
    • pp.87-97
    • /
    • 2016
  • In this study, a quantitative review was performed on the mechanical performance, permeation resistance of concrete, and durability of surface-modified coarse aggregates (SMCA) produced using low-quality recycled coarse aggregates, the surface of which was modified using a fine inorganic powder. The shear bond strength was first measured experimentally and the interface between the SMCA and the cement matrix was observed with field-emission scanning electron microscopy. The results showed that a reinforcement of the interfacial transition zone (ITZ), a weak part of the concrete, by coating the surface of the original coarse aggregate with surface-modification material, can help suppress the occurrence of microcracks and improve the mechanical performance of the aggregate. Also, the use of low-quality recycled coarse aggregates, the surfaces of which were modified using inorganic materials, resulted in improved strength, permeability, and durability of concrete. These results are thought to be due to the enhanced adhesion between the recycled coarse aggregates and the cement matrix, which resulted from the improved ITZ in the interface between a coarse aggregate and the cement matrix.

Physical and Mechanical Properties of Recycled Polymer Concrete (재생 폴리머 콘크리트의 물리.역학적 특성)

  • Baek, Seung-Chul;Kim, Young-Ik;Sung, Chan-Yong;Choi, Sang-Leung
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 2003.10a
    • /
    • pp.411-414
    • /
    • 2003
  • This study is performed to examine the physical and mechanical properties of recycled polymer concrete using recycled coarse aggregate and recycled fine aggregate. Tests for compressive strength, flexural strength and pulse velocity with replacement ratio of recycled coarse aggregate and recycled fine aggregate are performed. As a result, compressive strength, flexural strength and pulse velocity of polymer concrete containing recycled coarse aggregate are in the range of $826{\sim}849kgf/cm^2,\;192{\sim}200kgf/cm^2\;and\;3,932{\sim}4,000m/s$, respectively. Compressive strength, flexural strength and pulse velocity of polymer concrete containing crushed stone only are $805kgf/cm^2,\;197kgf/cm^2$ and 3,931 m/s, respectively. Accordingly, recycled aggregates is expected that can be utilizing as an aggregate of polymer concrete.

  • PDF

Mechanical and Drying Shrinkage of Concrete Replaced with Recycled Coarse Aggregate with Less than 13mm in Size (13mm이하 순환 굵은골재 치환에 따른 콘크리트의 역학적 특성 및 건조수축)

  • Lee, Sun-Jae;Kim, Sang-Sup;Park, Young-Jun;Han, Dong-Yeop;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2015.05a
    • /
    • pp.63-64
    • /
    • 2015
  • This study has analyzed mechanical and dry shrinkage properties according to the recycled coarse aggregate by nominal strength actually being widely used at the Remicon companies for the purpose of qualitative improvement of concrete, practical use and examination at various strengths. As a result, although the modulus of elasticity showed a tendency of getting decreased as the replacement ratio of recycled coarse aggregate has increased, the difference was insignificant while the compressive strength showed a tendency of about 3MPa increase in the recycled coarse aggregate replacement ratio of 30% compared to the ratio of 0%. In case of the dry shrinkage length variation ratio, the recycled coarse aggregate replacement ratio of 30% showed a tendency of about 20% shrinkage reduction compared to the ratio of 0%.

  • PDF

Properties of Polymer Permeability Concrete Using Recycled Aggregate (재생골재를 활용한 폴리머 투수콘크리트의 특성)

  • Kim, Young-Ik;Sung, Chan-Yong;Choi, Sang-Leung;Joung, Duck-Hyun
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 2003.10a
    • /
    • pp.415-418
    • /
    • 2003
  • This study is performed to examine properties of polymer permeability concrete using recycled coarse aggregate and blast furnace slag for application of structures needed permeability. Tests for compressive strength, flexural strength and pulse velocity with replacement ratio of recycled coarse aggregate are performed. As a result, compressive strength, flexural strength and coefficient of permeability of polymer permeability concrete containing recycled coarse aggregate are in the range of $180{\sim}200kgf/cm^2,\;58{\sim}64kgf/cm^2\;and\;4.6{\times}10^{-2}{\sim}6.9{\times}10^{-2}cm/s$, respectively. Compressive strength, flexural strength and pulse velocity of polymer concrete containing crushed stone only are $192kgf/cm^2,\;65kgf/cm^2\;and\;6.1{\times}10^{-2}cm/s$, respectively. Accordingly, recycled coarse aggregate is expected that can be utilizing as an aggregate of polymer permeability concrete.

  • PDF

Evaluations of Structural Performance of Recycled Aggregate Concrete According to Replacement Ratios (치환율에 따른 순환골재 콘크리트의 구조성능 분석)

  • Nam, Jin-Won;Kim, Ho-Jin;Kim, Sung-Bae;Kim, Jang-Ho Jay;Byun, Keun Joo
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.3 no.1
    • /
    • pp.54-64
    • /
    • 2007
  • This study is a fundamental research in order to establish the design code of recycled aggregate concrete structure. The structural properties of recycled aggregate concrete such as flexure, shear, fatigue, compression, and bond development are experimentally investigated and confirmed. In this study, laboratory-scale reinforced concrete beam, column, and pull-out test specimens using recycled coarse aggregate are manufactured. Then, the structural performances of recycled aggregate concrete according to replacement ratios of recycled coarse aggregate are evaluated. Also, finite element analysis using commercial code DIANA is carried out to predict the test results and the analysis results are compared with test results in this study. Structural test results showed that the structural performances of recycled aggregate concrete specimens with 60% replacement ratio are reduced by approximately 15-20%. These results indicated that the replacement ratio of recycled coarse aggregate within 30% is a suitable to use for structural members. The results of finite element analysis showed that the specimens with 30% replacement ratio possessed similar or more excellent structural performance than normal concrete specimens. However, recycled aggregate concrete with 60% replacement ratio of recycled coarse aggregate must be carefully considered for structural applications due to significant decrease of the failure loads.

  • PDF

Experimental investigation on hardened properties of recycled coarse aggregate concrete

  • Shohana, Shanjida A.;Hoque, Md. I.;Sobuz, Md. H.R.
    • Advances in concrete construction
    • /
    • v.10 no.5
    • /
    • pp.369-379
    • /
    • 2020
  • Reduction of disposal of waste materials due to construction demolition has become a great concern in recent decades. The research work presents the hardened properties of concrete where the partial substitution of recycled coarse aggregate with natural aggregate in amount of 0%, 10%, 30% and 50%. By using different mixed proportions, fresh and hardened properties of concrete were conducted for this investigation. These properties were compared with control concrete. It can be seen that all of the hardened properties of concrete were decreased with the increasing percentage of recycled aggregate in concrete mixes. It was noticed that up to 30% recycled aggregate replacement can be yielded the optimum strength when it used in normal concrete. Finally, it can be said that disposed recycled concrete utilizing as a partial replacement in natural aggregate is a great way to reuse and reduce environmental hazards which achieve sustainability approach in the construction industry.

Concrete physical properties with substitution ratio of recycled Coarse aggregate and recycled fine aggregate (순환굵은골재와 순환잔골재 치환율에 따른 콘크리트의 물리적 특성에 관한 연구)

  • Yoon, Seung-Joe;Seo, Soo-Yeon;Lee, Woo-Jin;Kim, Dae-Young
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2006.05b
    • /
    • pp.161-164
    • /
    • 2006
  • The main objective of this study was to evaluated the physical properties of concrete with substitution ratio of recycled fine aggregate and recycled coarse aggregate made of waste concrete. The replacement ratios of recycled coarse and fine aggregate decided 0%, 30%, 40% and 50% respectively to get the deregulate of floor space Index. The test result showed that compression strength of cylinder mold decrease with the substitution ratio increase but its strength of replaced recycled fine aggregate higher than OPC.

  • PDF

Properties of Mortar Adhered to the Recycled Coarse Aggregate in Cement Paste (시멘트풀 속에서의 순환굵은골재 부착모르타르의 성상변화에 관한 연구)

  • Moon, Dae-Joong;Choi, Jae-Jin
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.6 no.1
    • /
    • pp.95-102
    • /
    • 2011
  • Vicker's hardness and pore size distribution of mortar adhered to the recycled coarse aggregate were tested according to the strength level of original concrete of recycled coarse aggregate to find the change of mortar adhered to the recycled coarse aggregate in cement paste. The strength levels of original concrete of recycled coarse aggregate were 25.5MPa, 41.7MPa and 60.1MPa and the aggregates were used at the state of saturated surface dry condition and oven dry condition. The results of this experimentation indicated that the mean value of Vicker's hardness was increased according to age and strength of original concrete of recycled aggregate. Porosity of $100nm{\sim}10{\mu}m$ size was reduced and porosity of 6nm~100nm size was increased in cement paste.

  • PDF