• Journal of the Korea Concrete Institute
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• 제29권2호
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• pp.149-157
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• 2017

As the amount of construction wastes increase, reuse of recycled materials is being considered in research areas. While there are many experimental investigations focusing on development of mortar and concrete using the recycled materials, the studies regarding the fiber-reinforced cement composites (FRCCs) using recycled materials are still limited. In this paper, an experimental attempt has been made to investigate the effect of recycled fine aggregates and fly ash on the mechanical properties of PVA FRCCs. The cement and natural sand were respectively replaced by fly ash and recycled fine aggregates at two content levels, 25% and 50%. Ten types of PVA FRCCs mixes were fabricated and tested to investigate the flexural, compressive and direct tensile behaviors. The test results show that flexural, compressive and direct tensile strength were decreased with increase in fly ash content at all ages. In particular, flexural, compressive and direct tensile strengths of specimens, containing 50% recycled fine aggregates and 50% fly ash, showed the lowest values. The modulus of elasticity of specimens showed similar trend to the 28-day compressive strength. Poisson's ratio was increased with increase in fly ash and recycled fine aggregates content.

• Journal of the Korean Recycled Construction Resources Institute
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• 제2권2호
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• pp.166-171
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• 2014

This experimental study considers manufacturing method of the non-portland cement matrix for the light-weight building materials using blast furnace slag, paper ash, fly ash and polysilicon sludge the industrial by-product. For the experiment, we used paper ash by means of the foaming agent and alkali activator to make non-portland cement light-weight matrix. Various specimens were prepared with different types and addition ratios of the alkali activator. Then, the properties of these specimens were investigated by compressive strength test, bulk specific gravity. As a results, it was judged that experiment results of non-portland cement matrix with specific waste resources and alkali activators were useful as basic data for mixtures design and evaluation properties of lightweight non-portland cement building material.

• Cement Symposium
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• 30호
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• pp.69-74
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• 2003

• Cement Symposium
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• 통권45호
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• pp.129-133
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• 2018

• Journal of the Korea Institute of Building Construction
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• 제21권2호
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• pp.97-104
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• 2021

This study aims to develop non-sintered cement that can replace the Portland cement by utilizing industrial by-products. As a suggestion, the physical properties of non-sintered cement mortar depending on the curing method were investigated with ground granulated blast furnace slag, class C fly ash, and class F fly ash. As a result of the study, it was found that the strength performance and absorption rate were improved through the heat treatment process after steam curing. It was confirmed through crystal phase analysis that the hydration was accelerated after heat treatment, and the bonding material formed a dense internal structure.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.483-484
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• 2009

The purpose of this study is to evaluate the compressive behavior of SHCC mixing Fly ash. The parameter of this study are replacement level of fiber and Fly ash.

• Journal of the Korean Recycled Construction Resources Institute
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• 제1권1호
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• pp.35-41
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• 2013

In this study, we investigated the strength development and durability of geopolymer mortar using blast furnace slag only, and admixed with blast-furnace slag and fly ash as cementious materials in oder to develop cementless geopolymer concrete. In order to compare with the geopolymer mortar, the normal mortar using ordinary portland cement was also test. In view of the results, we found out that strength development, the resistance to freezing-thawing of the geopolymer mortar have better than the mortar using ordinary portland cement. Especially, using the combined with blast furnace slag and fly ash develop high strength of above 60 MPa, and improve the resistance of freezing-thawing of approximately 20%, but promote the velocity of carbonation of 2.2~3.5 times.

• Journal of the Korea institute for structural maintenance and inspection
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• 제22권2호
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• pp.154-160
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• 2018

Cement industries are considered key industries for reducing carbon emissions, and efforts are off the ground to reduce the use of cement in the concrete sector. As a part of this effort, research is off the ground to utilize a large amount of industrial by-products that can be used as a substitute for a part of cement. Concrete using industrial by-products has advantages such as durability, environment friendliness and economical efficiency, but there are problems such as retarding and early-age strength deterioration. Therefore, this study aimed to reduce the use of cement and solve the problem of early-age strength deterioration while using fly ash, which is an industrial by-product. Accordingly, it was confirmed that the strength was improved at all ages irrespective of curing temperature by accelerating the hydration reaction by using high fineness cement. Subsequently, high fineness cement was partially replaced with fly ash and the strength development characteristics were examined. As a result, it was possible to exhibit strength equal to or higher than ordinary portland cement even at the early age. Also, it was confirmed that even when the fly ash is replaced by 30%, it is possible to shorten the time for dismantling the forms of vertical and horizontal members.

• Journal of the Korean Recycled Construction Resources Institute
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• 제7권4호
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• pp.121-127
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• 2012

This paper is to present the strength estimation of the cement mortar incorporating 20% of fly ash by equivalent age method. ASTM C 1074 was applied to achieve apparent activation energy($E_a$). Cement mortar was cured at the temperature of $5^{\circ}C$, $20^{\circ}C$ and $35^{\circ}C$ respectively to measure the setting time and compressive strength at designed age. According to test results, it is found that an increase in curing temperature resulted in an acceleration of setting time. $E_a$ was achieved to 34.75 KJ/mol. It was also found that by estimating strength development with Plowman and Gompertz model, good agreement between calculated value and measured one was achieved.

• Cement Symposium
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• 통권37호
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• pp.90-95
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• 2010