• International Journal of Highway Engineering
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• v.14 no.3
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• pp.1-7
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• 2012

The purpose of this study was to review application of ASTM C 1260 for cement matrix with flyash and lithium nitrate using reactive aggregate. The experimental program included the accelerated mortar bar test (AMBT: ASTM C 1260) for the slate which was evaluated as reactive aggregate by ASTM C 1260 at the previous study. The cement, which was substituted by 10, 20, 30% flyash containing less than 10% CaO, could control ASR expansion. From the experiment applying lithium nitrate to control ASR, the mortar bar containing lithium nitrate showed more than 0.1% expansion at 14 days. This is probably due to dissolution of lithium nitrate in NaOH solution during test periods. Thus, it is necessary to adopt another test method to verify the control effect of lithium nitrate against alkali-silica reaction.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.261-262
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• 2009

The prevent methods of Alkali-Silica Reaction (ASR) are studying after the failure cases by ASR were reported in Korea. In this study, the freeze-thaw test and scaling test for premixed fly ash cement were performed. The ratio of fly ash and cement is 20 percent and 80 percent by weight of total cementious material. The results show that the dynamic modulus after 300 cycles the freeze-thaw test for most of specimen except the specimen have less 3% air was more than 90 % and the loss of weigh the specimen after 50 cycles scaling test was less than 1kg/$m^3$.

• Cement Symposium
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• s.38
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• pp.95-101
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• 2011

• 레미콘
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• no.10 s.73
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• pp.2-12
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• 2002

• 레미콘
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• no.10 s.45
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• pp.37-43
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• 1995

• Magazine of the Korea Concrete Institute
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• v.4 no.1
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• pp.11-16
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• 1992

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.2
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• pp.97-102
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• 2011

Amount of disposed construction materials like waste concrete is growing fast and use of the recycled aggregate for concrete has been seriously considered. But the use of the recycled aggregate is very limited because recycled aggregate has very low quality. Therefore, quality of recycled aggregate is very important in the manufacturing of recycled aggregate concrete. We have studied a series of research according to chemical processes and investigate the alkaline elimination effect of recycled aggregate and quality variation of recycled aggregate by sodium carbonate. Thereafter we have evaluated quality of recycled fine aggregate and experimented quality of this aggregate. As a results, we find that it is easy to eliminate the calcium hydroxide in recycled aggregate by sodium carbonate and the quality of recycled aggregate increase by elimination of alkaline.

• Journal of the Mineralogical Society of Korea
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• v.14 no.2
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• pp.85-98
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• 2001

This study deals with the petrographic examination of aggregates(ASTM C 295) which is one of the methods to diagnose the quality of aggregates for concrete artifacts. A number of examinations including size and sieve analysis, test on the coating material, description of the weathering and contamination condition, petrographic description, and qualitative and quantitative analyses on the rocks and minerals potential to alkali-aggregates reactivity are carried out to examine the quality of aggregates. Petrographic description method examined on the fluvial aggregates from Maewhacheon A, B area, Uljin-gun, Kyungnam province shows that weathering grade ranges from F(fresh) to WS(slightly weathered) and coating material and contamination are not in a harmful condition. The weight percentage of the alkali-aggregates reactive minerals or structurally unstable rocks of the aggregates from study area covers 26% and 19% of all aggregates, respectively. So it is necessary to further identify their quality through the chemical(ASTM C 289) and mortar-bar method (ASTM C 227).

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.789-792
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• 2008

Blast furnace slag doesn't have self-hydraulicity and it needs stimulants such as alkali to hydrate. Therefore using recycled aggregates erupted calcium hydroxides and blast furnace slag acquiring alkali stimulate could make a complementarily use of a recycling architectural material possible. In this study, we have discussed about characters of blast furnace slag and recycled aggregate firstly, and make recycled aggregate mortar and concrete using blast furnace slag for the experiment. The experiment is about mortar and concrete using recycled aggregate as a substitutional material of blast furnace slag. In this experiment, I replace blast furnace slag and aggregate with recycled aggregate. Conclusions through the test results analysis are as follows. And then, we added field experiment using concrete with composited materials.

• Journal of the Korea Institute of Building Construction
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• v.13 no.6
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• pp.602-608
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• 2013

The aim of this study is to investigate experimentally the effect of the combination of fine particle cement with high Blaine fineness (FC) and recycled aggregates on the engineering properties and micro structure of high volume blast furnace slag (BS) concrete with 75% BS and 21 MPa. FC manufactured by particle classification at the plant with Blaine fineness of more than $7000cm^2/g$ was used as additional alkali activator for high volume blast furnace slag concrete made with recycled fine and coarse aggregates. FC was replaced by 15, 20 and 25% OPC. Test results showed that the incorporation of FC resulted in an increase in the compressive strength compared to BS concrete without FC by as much as 30% due to accelerated hydration and associated latent hydraulic reaction. It was found that the use of FC and recycled aggregates played an important role in activating BS for high volume BS concrete by offering sufficient alkali.