• 레미콘
• /
• s.85
• /
• pp.58-69
• /
• 2005

본자료는 건설교통부에서 마련한 순환골재 품질기준 중 콘크리트 분야만을 발췌하여 회원사 업무에 도움주고자 편집게재 합니다. -편집자주

• Magazine of the Korea Concrete Institute
• /
• v.10 no.3
• /
• pp.13-22
• /
• 1998

• Magazine of the Korea Concrete Institute
• /
• v.10 no.3
• /
• pp.23-29
• /
• 1998

• Magazine of the Korea Concrete Institute
• /
• v.10 no.3
• /
• pp.37-47
• /
• 1998

• Magazine of the Korea Concrete Institute
• /
• v.9 no.2
• /
• pp.46-54
• /
• 1997

• Korean Journal of Construction Engineering and Management
• /
• v.20 no.4
• /
• pp.46-55
• /
• 2019

The exposed concrete has been widely used in building construction. Therefore, many researches are presented to secure a proper construction quality of exposed concrete. Low quality and management absence, however, still remained in construction fields. Thus, many studies have been conducted to improve the quality, but defects still occur in the exposed concrete finishing work. In this study, the causes of defects were analyzed by process in order to prevent the generation of defects and to enhance the need for integrated management to secure quality. In addition, a case study and AHP analysis have derived the importance of defects occurring in the exposed concrete finishing work. The study concluded that the occurrence of the exposed concrete finishing work needs to be managed throughout the process, not the management limited by one process, according to the causes of the existing defects, and integrated management is required to prevent defects and improve quality of exposed concrete finishing work.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.6 no.1
• /
• pp.69-78
• /
• 1986

The properties of ready mixed concrete are affected largely by quality of cement, grading and adhesive surface area water content of aggregate. The amount of variation must be found as soon as possible to minimize the variation of concrete properties. In this paper, a computer program is presented for fast and accurate calculation and modification of mix proportion according to property variation of concrete materials. The program calculates specified mix proportion, job mix proportion and batch weight of ready mixed concrete.

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

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.5 no.2
• /
• pp.121-129
• /
• 2017

In this study, the quality of recycled aggregate for concrete was investigated as the number of recycled aggregate crushing cycles, grinder and crusher, peeling and crushing. First, the quality of density, absorption ratio and solid content was improved as the separation distance decreased and the number of crushing increased, depending on the number of crushing of recycled aggregate and the distance between mantle and cone cave. The quality of density, absorption ratio and solid content was improved as the wire mesh used in striking plate and the number of hammers increased, depending on the type of striking plate and the number of hammers.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.4 no.2
• /
• pp.187-194
• /
• 2016

In this research, the influence of low-quality aggregate on engineering properties of concrete was experimentally evaluated. From a series of experiment, the results can be summarized as follow: first, the low-quality aggregate in concrete mixture caused up to 83% of decreased slump. For air content, low-quality aggregate increased air content of concrete mixture. Especially, when sea sand was used, because of the narrow gradation with small size, the air content was significantly increased. The compressive strength of concrete mixtures with low-quality aggregates were decreased up to 29% while some cases showed slightly increased compressive strength at early age. Additionally, the concrete mixture mixed with the exploded debris as a coarse aggregate showed approximately 5 to 20% of decreased compressive strength comparing with high-quality of manufacturing rock. In summary, because of the decreased workability of concrete mixture mixed with low-quality aggregates such as exploded debris, clay, and sea sand, it is concerned that worse quality of the ready mixed concrete, produced with the extra water to compensate the decreased workability.