• 한국산업융합학회 논문집
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• 제17권1호
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• pp.7-14
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• 2014

In this study, characteristic of elastic paving materials in bicycle road using polyurethane were studied experimentally. As a results, following their good result was obtained. Bicycle road packaging materials are flexural strength g test, ratio of mass change after freezing and thawing, repulsion elasticity test, water Permeation coefficient test and slip resistance test results showed good performance.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1992년도 봄 학술발표회 논문집
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• pp.19-22
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• 1992

Properties of concrete has effected on the dosage variation of AE superplasticizer agent, Therefore, this study is designed for analysis of concrete properies according to the dosage variation of AE superplasticizer agent , and is aimed to analyze the effect slump, air content, compressive strength, resistance of freezing-and-thawing and for presenting the reference data on the practical use.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1991년도 가을 학술발표회 논문집
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• pp.5-10
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• 1991

This study was performed to find out the effect about the spacing factor and durability factor to evaluate the durability of concrete in high-strength concrete with freezing and thawing as following each condition, 1) unit cement content : 500kg/$\textrm{m}^3$, 550kg/$\textrm{m}^3$ 2) water/cement ratio : 25%, 30%, 35% 3) air content : below 1.5%, 1.6~3.5%, 4~6%, over 7% From the results tested, a variation of air content was more effective to the durability of concrete than that of water/cement ratio and unit cement content.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 봄 학술발표회 논문집(I)
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• pp.129-136
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• 1998

In this study, lightweight aggregates were developed to see the possible application as a structural uses. For the evaluation purpose, several testings were conducted to compare the physical characteristics between the controlled lightweight aggregates and other lightweight aggregates purchased from different sources. The tests included property changes of fresh concrete and strength characteristics of hardened concrete for both normal and high strength ranges. In addition, a experiment was performed to analyze the freezing and thawing resistance of new lightweight aggregate concrete against other lightweight aggregate concrete against other lightweight aggregate concretes with some experimental parameters such as lightweight aggregates, curing conditions, and water-cement ratio. The test showed that the new lightweight aggregate could be used structural components. Continuous study will be planned for future evaluations.

• 콘크리트학회논문집
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• 제27권6호
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• pp.641-649
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• 2015

본 연구는 선행연구에서 도출한 다량의 광물질 혼화재를 사용한 고강도 콘크리트(HVMAC)의 내구성을 3성분계 콘크리트(TBC)와 시멘트만 사용한 콘크리트(NC)에 대해서 비교 평가하고자 하였다. 내구성 평가 종류는 염화물 침투 저항성, 동결융해 저항성, 두가지 전처리 조건으로 비교 평가한 탄산화 저항성, 5% 황산($H_2SO_4$), 10% 황산나트륨($Na_2SO_4$) 및 10% 황산마그네슘($MgSO_4$) 용액을 선정하여 황산 및 황산염 저항성 평가를 수행하였다. HVMAC는 모든 재령에서 우수한 염화물 침투 저항성을 나타내었고, 동결융해에 대한 내구성 지수가 100%에 가까운 우수한 결과를 나타내었다. 탄산화 저항성 평가 결과, HVMAC가 TBC보다 저감효과가 있었으며, 양생기간을 증가시켰을 때 콘크리트 내부조직을 치밀하게 만들어 탄산화 저항성을 향상시켰다. 황산 및 황산염 저항성 평가에서 HVMAC가 가장 우수한 것으로 나타났다. 다량의 혼화재 적용에 따른 수산화칼슘 생성량과 $C_3A$가 적어 황산 및 황산염에 의한 열화가 저감된 효과로 강도 감소 및 질량 변화가 작게 나타난 것으로 확인되었다.

• 한국농공학회지
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• 제32권3호
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• pp.39-46
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• 1990

This paper was analized the thermal conductivity of polystylene (TENSAR- GEOGRID) embeding into the subbase through frost penetration depth, frost heave, change of bearing capacity, and soil moisture movement due to freezing, thawing and icing actions, and their results were as follows : 1.The change of temperature into the sub-base was much increased by the Tensar-Geogrid insertion, and the frost penetration and frost heave were decreased as the thinner of the insulation thickness but the thawing velocity of melting period was appeared to be faster in case of non-insulated. 2.The frost heave had a close relationship with the thickness of insulations which was reasonably included anti-frost effects. 3.The moisture content during the freezing period of upper layer of the insulation insertion was increased by 15 per cent but it was returned to initial state of the thawing period, and at the down layer temporarily increased by 10 per cent and returned to the original state at once. 4.The insulation was acted as a function of distribution of surcharge, and the settlement of the sub-base was about 1.5 mm under 15 tonnage of load and which was included within the allowable limits. 5.The sliding resistance due to the icing which was induced by the insulation insertion into the sub-base was appeared as more 40 per cent than noninsulation area, so that the insulations should be restricted on the place such as mountains, curved and cross area which were required the braking power under the traffics.

• 한국도로학회논문집
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• 제18권6호
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• pp.123-130
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• 2016

OBJECTIVES : The objective of this research is to determine the moisture resistance of the freeze-thaw process occurring in low-noise porous pavement using either hydrated-lime or anti-freezing agent. Various additives were applied to low-noise porous asphalt, which is actively paved in South Korea, to overcome its disadvantages. Moreover, the optimum contents of hydrated-lime and anti-freezing agent and behavior properties of low-noise porous asphalt layer are determined using dynamic moduli via the freeze-thaw test. METHODS : The low-noise porous asphalt mixtures were made using gyratory compacters to investigate its properties with either hydrated-lime or anti-freezing agent. To determine the dynamic moduli of each mixture, impact resonance test was conducted. The applied standard for the freeze-thaw test of asphalt mixture is ASTM D 6857. The freeze-thaw and impact resonance tests were performed twice at each stage. The behavior properties were defined using finite element method, which was performed using the dynamic modulus data obtained from the freeze-thaw test and resonance frequencies obtained from non-destructive impact test. RESULTS : The results show that the coherence and strength of the low-noise porous asphalt mixture decreased continuously with the increase in the temperature of the mixture. The dynamic modulus of the normal low-noise porous asphalt mixture dramatically decreased after one cycle of freezing and thawing stages, which is more than that of other mixtures containing additives. The damage rate was higher when the freeze-thaw test was repeated. CONCLUSIONS : From the root mean squared error (RMSE) and mean percentage error (MPE) analyses, the addition rates of 1.5% hydrated-lime and 0.5% anti-freezing agent resulted in the strongest mixture having the highest moisture resistance compared to other specimens with each additive in 1 cycle freeze-thaw test. Moreover, the freeze-thaw resistance significantly improved when a hydrated-lime content of 0.5% was applied for the two cycles of the freeze-thaw test. Hence, the optimum contents of both hydrated-lime and anti-freezing agent are 0.5%.

• 한국도로학회논문집
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• 제18권1호
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• pp.43-55
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• 2016

PURPOSES : This study aims to develop a repair material that can enhance pavement performance, inducing rapid traffic opening through early strength development and fast setting time by utilizing MgO-based patching materials for repairing road pavements. METHODS : To consider the applicability of MgO-based patching materials for repairing domestic road pavements, first, strength development and setting time of the materials were evaluated, based on MgO to $KH_2PO_4$ ratio, water to binder ratio, and addition ratio of retarder (Borax), by which the optimal mixture ratio of the developed material was obtained. To validate the performance of the developed material as a repair material, the strength(compressive strength and bonding strength) and durability (freezing, thawing, and chloride ion penetration resistance) was checked through testing, and its applicability was evaluated. RESULTS : The results showed that when an MgO-based patching material was used, the condensation time was reduced by 80%, and the compressive strength was enhanced by approximately 300%, as compared to existing cement-based repair materials. In addition, it was observed that the strength (compressive strength and bonding strength) and durability (freezing and thawing, and chloride ion penetration resistance) showed an excellent performance that satisfied the regulations. CONCLUSIONS : The results imply that an emergent repair/restoration could be covered by a rapid-hardening cement to meet the traffic limitation (i.e. the traffic restriction is only several hours for repair treatment). Furthermore, MgO-based patching materials can improve bonding strength and durability compared to existing repair materials.

• 콘크리트학회논문집
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• 제17권5호
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• pp.703-708
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• 2005

본 연구에서는 에틸렌 초산 비닐 (EVA) 재유화형 분말수지를 혼입한 고유동 폴리머 시멘트 모르타르의 응결 시간 수밀성, 염화물이온 침투에 대한 저항성, 동결융해 저항성 및 중성화 깊이에 미치는 분말소포제 첨가율 및 폴리머-시멘트비의 영향에 대하여 검토하였다. 그 결과, 재유화형 분말수지를 혼입한 고유동 폴리머 시멘트 모르타르의 응결 시간은 분말소포제 첨가율에 관계없이 폴리머-시멘트비의 증가에 따라 지연되는 경향을 보였다. 또한 재유화형 분말수지를 혼입한 고유동 폴리머 시멘트 모르타르의 수밀성, 염화물 이온 침투 깊이 및 중성화 깊이는 분말소포제 첨가율에 관계없이 폴리머-시멘트비의 증가에 따라 감소하는 경향을 보였다. 재유화형 분말수지를 혼입한 고유동 폴리머 시멘트 모르타르의 동결융해 저항성의 개선은 재유화형 분말수지의 혼입에 의해 시멘트 수화물과 골재간의 접착성이 개선되기 때문이라 판단된다.

• 한국건설순환자원학회논문집
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• 제1권1호
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• pp.35-41
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• 2013

본 논문에서는 시멘트를 전혀 사용하지 않은 지오폴리머 콘크리트를 개발할 목적으로 시멘트 대신에 결합재로 고로슬래그 미분말 또는 고로슬래그 미분말과 플라이애시를 혼합 사용한 지오폴리머 모르타르의 강도발현과 탄산화 및 동결융해 저항성에 대해 검토하였다. 그리고 비교를 위해 보통포틀랜드 시멘트를 사용한 일반 모르타르에 대해서도 동일한 실험을 수행하였다. 그 결과, 지오폴리머 모르타르는 일반 시멘트 모르타르에 비해 강도발현, 동결융해 저항성 측면에서 우수한 것으로 나타났다. 특히 고로슬래그와 플라이애시를 혼합사용한 지오폴리머 모르타르는 압축강도 60MPa 이상 달성이 가능하고, 일반 시멘트 모르타르에 비하여 동결융해 저항성은 20% 정도 향상되나, 탄산화 속도는 2.2~3.5배 촉진되는 것으로 나타났다.