• Smart Structures and Systems
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• 제23권2호
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• pp.207-214
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• 2019

Achieving a pervious concrete (PC) with appropriate physical and mechanical properties used in pavement have been strongly investigated through the use of different materials specifically from the global waste materials of the populated areas. Discarded tires and the rubber tire particles have been currently manufactured as the recycled waste materials. In the current study, the combination of polymer, silica fume and rubber aggregates from rubber tire particles have been used to obtain an optimized PC resulting that the PC with silica fume, polymer and rubber aggregate replacement to mineral aggregate has greater compressive and flexural strength. The related flexural and compressive strength of the produced PC has been increased 31% and 18% compared to the mineral PC concrete, also, the impact resistance has been progressed 8% compared to the mineral aggregate PC and the permeability with Open Graded Fraction Course standard (OGFC). While the manufactured PC has significantly reduced the elasticity modulus of usual pervious concrete, the impact resistance has been remarkably improved.

• 한국염색가공학회지
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• 제9권6호
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• pp.58-67
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• 1997

PTCA(1,2,3-propanetricarboxylic acid) and BTCA(1,2,3-butanetetracarboxylic acid) are selected as new nonformaldehyde agents for ester crosslinking of cotton cellulose to replace the traditional DMDHEU reagent. A goal of this research is to propose unknown ester mechanism of cotton cellulose by PTCA or BTCA using crystal structure model suggested by Meyer and Takahashi. In pursuit of these goals, we have treated 100% cotton broad cloth with PTCA or BTCA and different catalysts. They were used with $NaH_2PO_2,\;NaH_2PO_4,\;Na_2HPO_4,\;NaH_2PO_2,\;Na_3PO_4,$ catalysts to produce nonformaldehyde fabric finishes. Treatments were applied to all cotton fabrics using a pad-dry -cure process. The esterfication of cotton treated with BTCA or PTCA was investigated using Fourier transform infrared(FT-IR) spectra and the breaking strength, abrasion retention and discoloration properties were determined to prove the durable finished fabrics. Patterns with respect to abrasion resistance were more complex. Because PTCA and BTCA add-ons were comparable, the data suggest that the more effective catalysts, $NaH_2PO_2$ and mixed phosphate $NaH_2PO_2/NaH_2PO_4$) are effecting either a great number of crosslinks in the cotton or producing crosslinks that differ in actual structure.

• 한국재료학회지
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• 제19권7호
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• pp.403-406
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• 2009

The friction characteristics of automotive brake friction materials that contained different ceramic content were investigated. Several kinds of raw materials, such as resin-based binder, reinforcing fiber, friction restraint, abrasive, and filling materials were mixed, pressed, and heated in order to make the brake friction materials. The contents of SiC and $BaSO_4$ changed from 5 vol% to 20 vol%, respectively. In addition to this, the content of $Al_2O_3$ adjusted from 1 vol% to 16 vol%. The surface morphology of the SiC containing sample appeared rough while more debris was observed when the contents of SiC increased. This implies that the SiC containing brake composite was not adequate for the automobile. However, the relatively smooth surface was observed in samples that contained the $Al_2O_3$. But the roughness was low with a content of 11 vol% $Al_2O_3$ compared to the other samples. This is consistent with the abrasive properties of the samples. In the case of $BaSO_4$ containing samples, the smoothes surface was observed in the contents of 15 vol% $BaSO_4$. Thus, it was concluded that the 11 vol% $Al_2O_3$ and 15 vol% $BaSO_4$ containing composite would be the optimum content for the brake composite. Similar to the results of the surface morphology, the abrasion resistance consistently decreased when the content of SiC increased. On the contrary, the sample that contained 11 vol% $Al_2O_3$ and 15 vol% $BaSO_4$ showed the highest abrasion resistance compared to the other samples.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.709-713
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• 1996

The ceramic has such high qualities as light weight, abrasion resistance, heat resistance compared with metal, but since it is breakable, it can't be used as structural material and it is desirable to joining metal which is full of toughness, but, according as the ceramic/metal joint is executed at high temperature, the joint residual stress develops near the joint sides in the process of cooling the high temperature down to the suitable temperature due to difference of the thermal expansion coefficient between ceramic and metal, and the joint residualstress lowers the fracture strength. In this study, to ensure security and improvement of bending strength, 1 studies on see distribution shape of residual stress according to high thermal cycle, and the influnence of theraml cycle and distribution shape of residual stess on joint-strength.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.140-141
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• 2021

Arc thermal spray process is widely used to protect the steel from corrosion and abrasion. In the present study, two different coatings i.e. Al and Al-5%Mg were used to compare their corrosion resistance performance and the effect of 5% Mg addition in the properties of deposited coating. The SEM results showed the more compact and less porous morphology of Al-5%Mg coating compared to Al. The corrosion resistance performance of both deposited coatings was studied in artificial ocean water with exposure periods and results are compared. The total impedance values of Al-5%Mg at 0.01 Hz exhibited highest with exposure periods might be attributed to the coating and corrosion products nature and morphology compared to Al coating.

• 한국구조물진단유지관리공학회 논문집
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• 제18권1호
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• pp.119-127
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• 2014

본 연구에서는 유황폴리머에멀젼 (SPE)을 반강성 포장용 주입재의 아크릴레이트 대체재로서 활용가능성과 성능향상재료 (PVA섬유)에 대한 역학적 성능과 내구성능을 평가하였다. 평가결과, 반강성 포장재의 충전률은 섬유의 혼입률이 증가함에 따라 충전률이 저하되었지만, 모든 배합조건에서 평균 92~94%로 측정되어 목표 성능인 90%를 만족하였다. 반강성 포장재의 마샬안정도 값은 최대 25.4kN으로 측정되어 반강성 포장재의 국내 기준인 5.0 kN 보다 약 4.7배 우수한 것으로 나타났다. 반강성 포장재의 동적안정도 평가결과, 휠 트래킹시험에 따른 변형저항성은 SPE를 대체한 배합조건이 보다 우수하였고, 모든 배합조건에서 45분 이후에는 변형량이 일정한 값에 수렴되어 동적안정도가 31,500회/mm로 동일한 결과를 나타내었다. 파단변형률은 최대 0.53% 정도로 나타나 아스팔트 포장재보다 우수한 강성으로 나타났다. 마모저항성 및 충격저항성 검토결과 모든 배합조건에서 손실률이 9.8~6.0%로 나타나 우수한 내마모성을 나타내었으며, 섬유를 0.3% 혼입한 경우 혼입하지 않은 Plain에 비하여 2.82배의 내충격성 향상을 나타내었다. 역학적성능 및 내구성능 등을 모두 고려하여 볼 때, 이 연구 범위에서는 SPE 대체율 30%가 적정 수준이고, 혼입률 0.3% 범위에서 PVA 섬유를 적용하면 우수한 인성을 갖는 반강성 포장재 제조가 가능 할 것으로 판단된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.305-308
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• 2005

The sulfuric acid may react with the hardened cement paste and originate expansive products which can induce swelling and disaggregation of concrete. The purpose of this study is to estimate the antibacterial performance of antibiotics and the effect of absorbed condition of restorative mortar, the number of coating times and coating contents with antibiotic on the fundamental properties of restorative mortar spead with antibiotics. Also, testing items such as bonding strength, abrasion contents, contents of water absorption, contents of air permeability was tested to estimate the fundamental properties in this study. In results, the novellus bacillus inhabiting in sewer concrete structures was restrained by antibiotics developed in this study. And bonding strength of restorative mortar spread with antibiotics was similla to that of plain mortar. But, resistance to abrasion, water absorption and air permeability of restorative mortar spread with antibiotics was superior to that of plain mortar.

• 대한건축학회논문집:구조계
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• 제35권5호
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• pp.153-160
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• 2019

The purpose of this study was to investigate the mechanical and durability characteristics of latex-modified concrete using ultra rapid hardening cement : four types of mechanical tests including compressive strength, modulus of elasticity, flexural strength and bond strength were performed; and seven types of durability tests including resistance of concrete to chloride ion penetration, freeze-thaw resistance, scaling resistance, coefficient of thermal expansion, cracking tendency, abrasion resistance and drying shrinkage were performed. Required material performance of each test was determined in accordance with the Korea specification for repair of concrete and pavement repairing materials. The test results satisfied the required material performances, and presented a good mechanical and durability characteristics. In particularly, the materials showed early development of compressive strength, flexural strength and bond strength at 3 and 4 hours after curing. SEM photos were also taken to investigate the micro structures of the materials after chloride ion penetration test.

• 한국의류산업학회지
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• 제17권5호
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• pp.781-792
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• 2015

This study aims to develop a spring/fall motorcycle jacket for quick service transporter. Depending on the results of the previous research, this study produced the tested jacket which was improved in material, pattern, and design. For the tested jacket, 100% polyester fabric excellent in strength, durability and abrasion-resistance was selected as a major material, and Cordura was used as a partial material to improve the strength and abrasion-resistance of the sleeve side lines, elbow and shoulder areas. The retro-reflection material was applied partially in order to improve visibility of the jacket in the night or in a dark place. A total of 7 pockets were composed in the jacket for the sufficient storage spaces. The functional design elements such as the 2-way zipper and the placket at the center front, the action pleats at the upper part of back armholes, the pit-zip at armpit were applied. In addition, the sleeve pattern was bent with the shape of elbow curvature in time of driving and the back length of the jacket was lengthened 4cm. As a result of the appearance assessment, there was a significant difference from the existing jacket in all items but chest size, shoulder width, cuffs circumference, and jacket hemline circumference. In motion adaptability and field activity appropriateness assessments, the assessment grade for all items was found to be commonly higher than that of the existing jacket, and thus, the tested jacket was assessed to be suitable for a motorcycle jacket design for the quick service transporters.

• 한국건축시공학회지
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• 제13권5호
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• pp.449-456
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• 2013

본 연구는 제주도 현무암 골재에 대해 콘크리트용 굵은 골재로서의 품질기준의 적합성을 평가하였다. 골재의 품질 평가는 KS 기준에서 요구하는 골재안정성, 골재마모저항성, 골재파쇄성 실험을 하였다. 더불어, 현무암 골재의 성분 분석을 위해 XRD, XRF, Porosity를 분석하였으며, 현무암의 강도는 콘크리트용 굵은 골재로서 다른 지역에서 주로 사용되는 화강암, 안산암 그리고 사암의 압축 및 인장강도 결과 값과 비교 평가하였다. 전반적으로, 골재의 기계적 특성 평가 결과, 일부 지역의 현무암 골재는 KS 기준을 만족하지 못하였다. 그러나 제주지역의 현무암의 압축강도와 인장강도는 타 지역의 암석보다 높았다.