• 한국농공학회논문집
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• 제48권7호
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• pp.25-31
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• 2006

Permeable polymer concretes can be applied to roads, sidewalks, river embankment, drain pipes, conduits, retaining walls, yards, parking lots, plazas, interlocking blocks, etc. This study was to explore a possibility of using bottom ash as filler and recycled coarse aggregate of industrial by-products for permeable polymer concrete. The tests carried out at $20{\pm}1^{\circ}C$ and $60{\pm}2%$ relative humidity. At 7 days of curing, unit weight, void ratio, compressive and flexural strength and coefficient of permeability ranged between $1,652{\sim}1,828kgf/m^{3},\;15{\sim}29+%,\;18.2{\sim}24.5\;MPa,\;6.4{\sim}8.4\;MPa\;and\;6.8{\times}10^{-2}{\sim}1.7{\times}10^{-1}\;cm/s$, respectively. It was concluded that the bottom ash and recycled coarse .aggregate can be used in the permeable polymer concrete.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.70-75
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• 1999

The purpose of this study is to recycle the waste concrete which is generated in large quantities as crushed stone in construction works. This study deals with the comparative analysis on the construction works and engineering properties of recycled aggregate concrete through physical experiment. The experimental variables are the kinds of aggregates, some different aggregate composition, and W/C ratio(0.40, 0.45, 0.50). It is able to find from the experimental results that the recycled aggregate concrete is good as general concrete on the construction works and engineering propperties. In addition to, the reliable regression analysis equations between compressive strength and various experimental data for recycled aggregate concrete are presented.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.71-72
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• 2009

순환골재를 사용한 콘크리트를 구조부재에 활용하기 위해선 이형철근과 순환골재 콘크리트의 부착성능 규명이 절실히 요구된다. 본 연구에서는 순환 굵은 골재 및 잔골재 치환율과 철근 위치를 변수로 이형 철근과 순환 잔골재 콘크리트의 부착성능을 평가하고자 하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.33-34
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• 2009

본 연구는 순환굵은골재와 잔골재의 치환율을 변수로 하여 5개의 실물모형 기둥 실험체를 제작하여 축하중하에서 실험을 진행하였으며 KCI2007에서 규정하고 있는 압축 응력값을 만족하는 것으로 나타나 KCI 규준식은 순환골재를 사용한 철근콘크리트 기둥 설계에서 적용 가능한 것으로 판단된다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.101-103
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• 2011

Various desired performances of concrete cannot be always obtained by current conventional mix proportion methods for recycled aggregate concrete (RAC). This paper suggests a new design method of mix proportion for RAC to reduce the number of trial mixes using genetic algorithm (GA) which has been an optimization technique to solve the multi-object problem. In mix design method by GA, several fitness functions for the required properties of concrete, i.e., slump, strength, price, and carbonation speed coefficient were considered based on conventional data or fitness function. As a result, various optimum mix proportions for RAC that meet required performances were obtained and the risk evaluation was also conducted for selected mixtures.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.89-92
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• 2005

An experimental study was conducted to study the mechanical properties of recycled aggregate concrete in accordance with the different replacement ratios of recycled fine and coarse aggregate, ranging from 0$\%$ to 30$\%$ and 0$\%$ to 50$\%$, respectively. According to increase of these replacement ratios, compressive strengths and elastic modulus are reduced down to $10\∼20\%$ and $15\∼30\%$, respectively. The reducing ratios of elastic modulus are more distinct than that of compressive strength. For the selection of replacement ratios of recycled aggregate for structural concrete properly, it is necessary to evaluate the elastic modulus carefully.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.1623-1629
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• 2008

The purpose of this research is to assess the application of recycled-aggregate that is gained from construction wastes as the material of compaction pile method. At the same time, the development of the new technique rectifies defects of the existing compaction pile method for soft ground improvement. In this research, model tests were conducted for analyzing the effect of the soft ground improvement by porous concrete pile using recycled aggregate. Through the results of the model tests, the behavior of settlement on composition ground with surcharge pressure were elucidated.

• Computers and Concrete
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• 제16권4호
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• pp.643-667
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• 2015

3-dimentional precast recycled aggregate concrete (RAC) finite element models were developed by means of the platform OpenSees to implement sophisticated nonlinear model subjected to seismic loads. Efforts were devoted to the dynamic responses (including dynamic characteristics, acceleration amplifications, displacements, story drifts) and capacity curve. In addition, this study extended the prediction on dynamic response of precast RAC model by parametric study of material properties that represent the replacement percentage of recycled coarse aggregate (RCA). Principles and assumptions that represent characteristics of precast structure and influence of the interface between head of column and cast-in-place (CIP) joint on the stiffness of the joints was put forward and validated by test results. The comparison between simulated and tested results of the precast RAC frame shows a good correlation with most of the relative errors about 25% in general. Therefore, the adopted assumptions and the platform OpenSees are a viable approach to simulate the dynamic response of precast frames made of RAC.

• Computers and Concrete
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• 제32권4호
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• pp.383-392
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• 2023

The mechanical properties of Recycled Aggregate Concrete (RAC) with 100 percent Recycled Coarse Aggregate (RCA) under loading rates were investigated in depth. The theoretical model was validated utilizing the RAC elastic modulus obtained from cylindrical specimens subjected to various strain rates. Viscoelastic theories have traditionally been used to describe creep and relaxation of viscoelastic materials at low strain rates. In this study, viscoelastic theories were extended to the time domain of high strain rates. The theory proposed was known as reversed viscoelastic theory. Normalized Dirichlet-Prony theory was used as an illustration, and its parameters were determined. Comparing the predicted results to the experimental data revealed a high level of concordance. This methodology demonstrated its ability to characterize the strain rate effect for viscoelastic materials, as well as its applicability for determining not only the elastic modulus for viscoelastic materials, but also their shear and bulk moduli.

• 한국건설순환자원학회논문집
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• 제5권2호
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• pp.160-167
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• 2017

본 연구에서는 알칼리 활성화 결합재 및 순환골재를 동시에 활용한 100% 순환자원 보투수성 알칼리 결합재 블록의 개발 가능성을 확인하고자 한다. 또한, 공극률, 압축강도, 투수계수, 보수량, 흡수율 및 증발성 등의 특성 시험 방법을 정립하여 표준화의 기초단계를 확보하였다. 그 결과, 순환골재를 이용한 알칼리 활성화 결합재 블록은 액상 규산나트륨 및 초기고온양생을 통해 24MPa급의 보투수성 블록을 제조할 수 있었다. 또한 순환골재를 적용한 경우 천연골재보다 보투수 블록의 보수량, 흡수율 및 상대흡수율에서 효과적인 결과가 나타났다. 종합적으로, 알칼리 활성화 결합재를 기반으로 순환골재 및 액상폴리머를 사용할 경우 보수량, 흡수율 및 상대흡수율 증진이 가능하고 일반 콘크리트 인터로킹 블록과 비교해 약 10% 수준의 표면온도 저감효과를 가진 보투수성 블록의 제조를 기대할 수 있다.