• 대한토목학회논문집
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• 제32권5A호
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• pp.299-305
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• 2012

본 연구는 수용성 폴리머의 일종인 폴리비닐아세테이트(Polyvinyl Acetate, 이하 PVAc)를 사용한 폴리머 시멘트 모르타르와 콘크리트의 특성에 관한 평가를 통하여 친환경 콘크리트 개발을 위한 기초자료를 획득하는 것이다. 이를 위해 PVAc를 혼입하지 않은 시멘트 모르타르 및 콘크리트와 결합재 대비 3%, 6%, 9%, 12%의 PVAc를 각각 혼입한 폴리머 시멘트 모르타르 및 콘크리트와의 비교분석을 통한 물리적 특성을 평가하였으며, 폴리머 혼입에 따라 늘어나는 공기량을 제어하기 위해 소포제를 첨가하여 PVAc 콘크리트의 특성을 평가하였다. 그 결과 PVAc가 혼입된 폴리머 시멘트 모르타르의 경우 압축강도는 낮아지나 휨강도와 건조수축의 성능이 향상되는 것으로 나타났으며, 콘크리트의 경우 혼입율이 6%일 때가 압축강도, 인장강도, 휨강도 및 탄성계수가 높아지는 것을 확인할 수 있었다.

• 한국지반신소재학회논문집
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• 제15권2호
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• pp.1-12
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• 2016

본 연구에서는 기존의 심층혼합처리공법용 안정재의 문제점을 해결하기 위해 탈황분진을 이용하여 개발한 친환경 지반안정재(CMD-SOIL)의 적용성을 평가하기 위해 실내배합시험 및 현장시험시공을 실시하였다. 실내배합시험 결과 함수비, 투입비 및 W/B 변화에 따른 CMD-SOIL의 일축압축강도가 기존의 고로슬래그 시멘트와 비교하여 최대 1.136배 큰 것으로 나타났고, 패각이 함유된 흙 재료에서는 최대 1.222배, 부상토가 혼합된 시료에서는 최대 1.363배 큰 것으로 나타났다. 또한 현장시험시공 결과, 실내배합강도와 현장강도의 비(${\lambda}$)가 0.77로 나타나 기존의 연구결과(${\lambda}=2/3$)와 유사한 경향을 보이고 있어 기존의 안정재와 비교하여 동등 이상의 성능을 발휘할 수 있을 것으로 판단된다.

• 한국지반환경공학회 논문집
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• 제14권6호
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• pp.31-38
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• 2013

본 논문에서는 친환경고화재와 자연토, 물을 혼합하여 포설한 후 다짐장비를 이용하여 지반을 고결시키는 임도포장공법에 대한 기초연구를 수행하였다. 포장체의 목표강도는 2.0MPa로 설정하였고 고화재의 혼합비, 자연토의 종류, 양생기간별로 공시체를 제작하여 일축압축강도특성과 내구성을 평가하였다. 일축압축강도시험은 동일한 혼합비의 시멘트를 혼합한 공시체와 친환경고화재를 혼합한 공시체를 제작하여 강도를 비교하였으며, 내구성 평가를 위한 시험은 표면마모시험, 유수저항성 시험 등을 수행하였다. 또한, 임도의 특성상 탐방객들도 이용이 가능하므로 보행만족도를 평가하기 위하여 쇠구슬과 골프공을 이용한 SB, GB시험을 수행하였다.

• 한국세라믹학회지
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• 제52권2호
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• pp.150-153
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• 2015

Recently, research on geopolymeric concrete that does not use cement as a binder has been actively investigated. Geopolymeric concrete is cement-free concrete. Masato, ocher and/or soil has been solidified into geopolymeric concrete by the reaction of specifically modified silicate as an alkali activator and inorganic binding materials such as blast furnace slag, fly ash or meta-kaolin, which is cured at room temperature to exhibit high compressive strengths. Based on the results, this study shows how geopolymeric concrete that uses specifically modified silicate and inorganic binding materials is implemented as eco-cement with no cement.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.111-112
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• 2022

In this present study, the corrosion mitigation effect of conifer cone extract (CC) was examined in the cement mortar to improve the steel rebar (SR) corrosion resistance. The corrosion inhibition properties of the SR embedded in cement mortar (CM) admixed with different percentage (0, 0.5, 1.0, 1.5, 2.0 %) of CC was studied by open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) tests. This result confirms that the CM with 0.5% of CC added has better corrosion resistance than the blank specimen (0 % of CC). Although, the percentage of CC increase above 0.5%, the CC could yield a negative impact on CM properties in terms of reducing the corrosion resistance due to the reduction of cement hydration reaction. It was highlighted that the SR embedded in CM containing 0.5% of CC had increased corrosion resistance.

• Geomechanics and Engineering
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• 제33권1호
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• pp.41-51
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• 2023

Cementitious materials such as Ordinary Portland Cement (OPC), fly ash, lime, and bitumen have been employed for soil improvement over the years. However, due to the environmental concerns associated with the use of OPC, substituting OPC with calcium sulfoaluminate (CSA) cement offers good potential for ground improvement because it is more eco-friendly. Although earlier research has investigated the stabilizing effects of CSA cement-treated sand, no attempt has been made to examine soil behavior under high confining pressure. As a result, this study aimed to investigate the shear strength and mechanical behavior of CSA cement-treated sand using a consolidated drained (CD) triaxial test with high confining pressure. The microstructure of the examined sand samples was investigated using scanning electron microscopy. This study used sand with CSA cement contents of 3%, 5%, and 7% and confining pressures of 0.5, 1.0, and 1.5 MPa. It revealed that the confining pressures and CSA cement content significantly affected the stress-strain and volumetric change behavior of CSA cement-treated sand at high confining pressures.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.144-145
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• 2020

Recently, the cement industry has been using various wastes as raw materials and fuel for cement as an eco-friendly business. However, most of these waste resources contain large amounts of chloride and alkali, which are concentrated in manufacturing facilities and adversely affect cement production products. Accordingly, in the cement production process, the chlorine ion contained in cement is managed by introducing the Chlorine Bypass System (CBS) into the manufacturing facility and releasing the dust. However, the processing volume of CBS-Dust has been limited due to the shortage of domestic processing companies, and the cost has also been raised, requiring measures to be taken in dealing with CBS-Dust. In this study, rheological properties of CBS-Dust incorporated paste are tested. With the increase of CBS-Dust, flow was decreased due to enhanced viscosity.

• Architectural research
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• 제11권1호
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• pp.25-33
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• 2009

This study presents the testing of 15 hwangtoh-based cementless concrete mixes to explore the significance and limitations of the development of eco-friendly concrete without carbon dioxide emissions while maintaining various beneficial effects. Hwangtoh, which is a kind of kaolin, was incorporated with inorganic materials, such as calcium hydroxide, to produce a cement-less binder. The main variables investigated were the water-to-binder ratio and fine aggregate-to-total aggregate ratio to ascertain the reliable mixing design of hwangtoh-based cementless concrete. The variation of slump with elapsed time was recorded in fresh concrete specimens. Mechanical properties of hardened concrete were also measured: including compressive strength gain, splitting tensile strength, moduli of rupture and elasticity, stress-strain relationship, and bond resistance. In addition, mechanical properties of hwangtoh-based cement-less concrete were compared with those of ordinary portland cement (OPC) concrete and predictions obtained from the design equations specified in ACI 318-05 and CEB-FIP for OPC concrete, wherever possible. Test results show that the mechanical properties of hwangtoh-based concrete were significantly influenced by the water-to-binder ratio and to less extend by fine aggregate-to-total aggregate ratio. The moduli of rupture and elasticity of hwangtoh-based concrete were generally lower than those of OPC concrete. In addition, the stress-strain and bond stress-slip relationships measured from hwangtoh-based concrete showed little agreement with the design model specified in CEB-FIP. However, the measured moduli of rupture and elasticity, and bond strength were higher than those given in ACI 318-05 and CEB-FIP. Overall, the test results suggest that the hwangtoh-based concrete shows highly effective performance and great potential as an environmental-friendly building material.

• 한국건축시공학회지
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• 제12권2호
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• pp.152-160
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• 2012

건축공사의 선진화는 시공기술과 함께 재료의 성능향상이 동반되어야 한다. 특히 습식공사의 경우 인력에 의한 의존도가 높고, 재료 사용의 다양화가 미진한 대표적인 공정이라 할 수 있다. 이와 같은 마감 모르타르 공사에서 품질 및 시공의 선진화를 위한 다양한 모르타르 재료에 대한 물리적 특성 시험을 통하여 비교·확인함으로 향후 습식 미장공사의 다양한 재료 적용과 기계화 시공을 넘어 친환경 기능성 재료의 사용까지 발전될 수 있도록 제안해 보았다. 특히 공장생산 제품인 건조시멘트 모르타르 제품을 기준으로 기계화 시공이 가능한 수지플라스터와 친환경 석고플라스터의 사용 확대를 위한 각 재료의 품질 특성에 관한 연구를 통해 마감 모르타르 공사의 다양화와 선진화 방향을 제시하였다. 그 결과 압축강도의 경우 시멘트를 기본으로 하는 재료에서는 초기 양생조건이 품질 확보에 가장 중요한 관리 항목임을 다시 한번 확인할 수 있었으며, 마감 모르타르의 작업 후 균열 안정성에 영향을 주는 길이변화의 경우 석고플라스터가 가장 우수한 결과를 나타냈으며, 최종 응결이 빠르게 나타남으로 후속 공정을 보다 빨리 진행할 수 있어 공기단축에도 기여할 수 있을 것으로 판단된다.

• Advances in concrete construction
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• 제9권3호
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• pp.279-287
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• 2020

This paper focuses on the engineering properties of Bentonite-Cement-Sodium silicate (BCS) grout, which was prepared by partially replacing the ordinary Portland cement in Cement-Sodium silicate grout with lithium bentonite (Li-bent) and sodium bentonite (Na-bent), respectively. The effect of different Water-to-Solid ratio (W/S) and various replacement percentages of bentonite on the apparent viscosity, bleeding, setting time, and early compressive strength of BCS grout were investigated. The XRD method was used to detect its hydration products. The results showed that both bentonites played a positive role in the stability of BCS grout, increased its apparent viscosity. Na-bent prolonged the setting time of BCS, while 5% of Li-bent shortened the setting time of BCS. The XRD analysis indicated that the hydration products between the mixture containing Na-bent and Li-bent did not differ much. Using bentonite as supplementary cementitious material (SCM) to replace partial cement is a promising way to cut down on carbon dioxide emissions and to produce low-cost, eco-friendly, non-toxic, and water-resistant grout. In addition, Li-bent was superior to Na-bent in improving the strength and the thickening of BCS grouts.