• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.81-84
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• 2005

We investigated the effect of inorganic impurities such as clay bricks and asphalt concrete in recycled aggregate on the properties of lean concrete. The optimized moisture content of lean concrete with clay bricks increased, because the absorption ratio of clay bricks is high. On the other hand, lean concrete with asphalt concrete produced an opposite result owing to low absorption ratio. The results showed that inorganic impurities did not have a significant effect on compressive .strength of lean concrete containing below 30$\%$ clay bricks and below 10$\%$ asphalt concrete.

• Magazine of RCR
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• v.18 no.3
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• pp.57-62
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• 2023

• Applied Chemistry for Engineering
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• v.17 no.6
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• pp.614-618
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• 2006

Recycling of asphalt including shingle is much important for economic aspects such as a decrease of treatment cost. This research was carried out in order to process the recycled shingle to asphalt concrete which is a pavement material. Pure asphalt and the mixture of recycled asphalt were tested in terms of the thermal characteristics, viscosity, and penetration. DSC analysis indicates that the thermal characteristics of separate shingle showed similar properties regardless of processing conditions. Melting of asphalt separated from shingle occurred at $170^{\circ}C$. The viscosity and penetration of the 1~5 wt% of mixed recycling asphalt and raw material asphalt are suitable for the pavement material standard.

• Magazine of RCR
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• v.16 no.2
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• pp.40-45
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• 2021

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.113-116
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• 2007

This is a research for evaluated recycled glass powder to add asphalt concrete filler. To make a comparative study, Mechanical performance of lime stone and slag dust Mixtures was evaluated according to test procedure. Lab. performance tests included marshall stability, indirect tensile strength, resilient modulus and wheel tracking. Water resistance tests were evaluated by marshall strength ratio and tensile strength ratio. In conclusion, Results of mechanical performance showed that recycled glass powder mixtures were equivalent to conventional mixtures. Especially, result of tensile strength ratio tested recycled glass powder mixtures was superior to conventional mixtures.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.2
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• pp.51-57
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• 2010

Many models have been used to represent the effects of confining stress, bulk stress, and shear stress on the value of the resilient modulus (Mr). This study was conducted to estimate Mr of the recycled materials such as recycled concrete aggregate (RCA) and recycled asphalt pavement (RAP) through the repeated load cyclic test. Also, two models were applied to estimation of Mr for comparing between measured Mr values and predicted Mr values. The first model (A-model) can provide a quick and easy estimation of the Mr based on the bulk stress, while the second model (N-model) includes not only the bulk stress but also the shear stress. Statistical analysis indicated that all results using the both of models are significant at a 95 % confidence level. Therefore, the both of models could be used as an effective prediction model of Mr for RCA and RAP. Especially, the Model 2 including the parameters of the bulk stress and the shear stress could give more reliable estimation at the high range of Mr values.

• Magazine of RCR
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• v.11 no.2
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• pp.40-47
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• 2016

• Magazine of RCR
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• v.10 no.4
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• pp.28-32
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• 2015

• Magazine of RCR
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• v.4 no.3
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• pp.24-29
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• 2009

• International Journal of Highway Engineering
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• v.14 no.3
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• pp.69-76
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• 2012

A recent shortage in Korean aggregate market leads a social demand to utilize recycled aggregate to more advanced level, such as the use in concrete structures or paving materials for surface and base layers. Government announced a recycled aggregate guideline in 2009 to provide an institutional framework for recycled aggregate in such an up-scaled use. The use of recycled aggregate in such use; however, is very minimal. This paper evaluates the validity of the impurity content criteria of recycled aggregate for lean concrete base through a series of material tests. The analysis results shows that reclaimed asphalt pavement (RAP) in recycled aggregate not only influence a strength lean concrete adversely, but also influence negatively on an absorption and abrasion characteristics of aggregate system significantly that made those two indices lower. Since absorption and abrasion characteristics are very important indices for recycled aggregate quality, RAP in recycled aggregate could significantly mislead the recycled aggregate qualification. This paper provides a suggestion to resolve these problems.