극저온 파쇄 폐타이어 분말을 이용한 Pre-mix 혼합 CRM 개질 아스팔트 바인더의 저장안정성 평가

나일호,박지용 한국아스팔트학회 2022 한국아스팔트학회지 Vol.12 No.2

The amount of domestic waste tires is increasing, and in order to utilize them, cement kiln heat sources are used, solid fuel products, and rubber powder are processed and used. In the case of road pavement, CRM-modified asphalt is applied using the rubber powder of waste tires. However, there is a difference in storage stability depending on the crushing conditions of CRM modified asphalt, and it is necessary to investigate this. Through this experiment, it was confirmed that the normal-temperature crushing CRM binder showed a sinking phenomenon and the very low temperature crushing CRM binder floating. Based on these characteristics, it can be used as basic data when designing an asphalt mixture.

노면전차 매립형 궤도 아스팔트 포장구조의 영구변형 및 균열발생 특성 분석

나일호,최영태,이수형 한국철도학회 2020 한국철도학회논문집 Vol.23 No.7

After concrete slabs of tramways are paved with asphalt concrete, separation, cracking, and permanent deformation occurred due to the reduction of shear force caused by vehicle passing and temperature change. In order to mitigate this problem, there have been many studies to improve long-term performance by applying guss asphalt and modified asphalt. A single layer with guss asphalt results only in better resistance to reflective cracking but is relatively weak against permanent deformation. The multiple layer model with an asphalt mixture on top of guss asphalt leads to better reflective cracking and permanent deformation.

유화 아스팔트가 시멘트 모르터의 강도특성과 동결융해에 의한 질량 손실률에 미치는 영향 평가

나일호,박지용,백인혁,김광우 한국철도학회 2019 한국철도학회논문집 Vol.22 No.9

Cracking of cement mortar mainly occurs via sedimentation and contraction cracks in the early period anddrying shrinkage cracks after hardening. To solve these problems, CAM (Cement Asphalt Mortar), which is a mixedcompound of asphalt and cement, has been developed and subjected to dynamic study. The reason for using asphalt isthat its performance in terms of drying shrinkage, watertightness, and chemical resistance is better than that of cement. In this study, three different contents of CAM (one of was hardened, not the others) were used for the experiment. Threeaggregates were used (2mm, 5mm crushed sand, and standard sand) and two types of emulsified asphalt were used(EA40, EA50). Certain tendencies of strength and mass loss rate with increase in content of emulsified asphalt, sand,and A/C ratio were observed. The results of this study can be applied to the field as fundamental data.

철도 휠트랙킹 시험을 이용한 아스팔트 콘크리트 도상의 개질아스팔트 성능평가

나일호,김광우,김현환 한국아스팔트학회 2022 한국아스팔트학회지 Vol.12 No.1

Asphalt is produced in the refining process of crude oil. So in itself, it's a lot of weakness. In particular, asphalt concrete is a risk of damage because of rutting in high temperatures and brittleness at low temperatures when used in asphalt concrete track by great temperature sensitivity. However, modified asphalt using various additives can prevent the damages like rutting and crack and extend the pavement service life. In particular, polymer-modified asphalt enhances rutting resistance due to improved elasticity at a high service temperature of 60~80°C. This study evaluated polymer-modified asphalt to measure the base strong characteristics and applicability of the asphalt concrete track for railways.

철도 아스팔트 콘크리트 궤도의 시공정밀도 및 주행 안정성 확보를 위한 실현장(중부내륙선 일부) 적용 사례 연구

나일호,정원우,박지용 한국아스팔트학회 2023 한국아스팔트학회지 Vol.13 No.1

Asphalt concrete tracks are excellent in terms of workability and economy, and have the advantage of improving running stability and easy maintenance. However, because it is constructed on site in the buttom-up method, methods for precise construction are required. The composition of the asphalt concrete track system can be divided into subgrade installation, asphalt concrete ballast installation, track installation, and vertical and horizontal resistance equipment, Management through guide wire and measurement is required to secure the precision of each process. If studies to increase precision are continuously promoted through these field installation studies, it will contribute to the technological development of asphalt concrete tracks.

통계적 근거에 의한 표층 아스팔트 혼합물 변형강도의 배합강도 설정연구

나일호,김진철,도영수,김광우 한국도로학회 2009 한국도로학회논문집 Vol.11 No.1

This study was performed to establish the process mean which is statistically satisfying the critical limit of deformation strength (SD), which is found to reflect rutting characteristics of asphalt mixture relatively well. The process means were determined using the critical SD values (3 MPa for local highway and 4 MPa for arterial highways), which were obtained from correlation analysis of APA and SD test data of actual highway projects, and coefficient of variation of 32 combinations of domestic mixtures. The process means of 3.2 MPa for local highway and 4.25 MPa for arterial highways were suggested when using 3 specimens (diameter of 100mm). However, since these values are based on the loading speed of 30mm/min, the higher values, 3.5 MPa for local highway and 4.5 MPa for arterial highways, were suggested, respectively, if the loading speed of 50mm/min is applied using the old Marshall machine, which should give higher test values. 본 연구는 아스팔트 혼합물의 소성변형 특성을 비교적 잘 반영하는 변형강도치가 안정적으로 배합설계시 기준강도를 만족할 수 있는 배합강도를 통계적 분석에 의해 제시하기 위하여 이루어졌다. 따라서 실제의 도로 혼합물의 APA 시험과의 변형강도의 상관관계로부터 얻어진 혼합물의 임계치 (일반도로 3MPa, 간선도로 4MPa)와 국내 32개 조합의 아스팔트 혼합물의 변형강도 값을 통해 변동계수( )를 계산하고 이를 이용하여 배합강도를 산정하였다. 공시체를 3개 사용할 경우 직경 100mm 공시체의 일반도로와 간선도로의 혼합물의 배합강도는 3.2MPa와 4.25MPa로 설정되었다. 또한, 이 값은 재하속도30mm/min의 장비에서 얻어진 값이므로 재하속도가 50mm/min로 고정된 마샬안정도 시험기 사용시에는 더 높은 값인 3.5MPa와 4.5MPa이 각각의 기준으로 설정되었다.

비파괴 밀도시험을 통한 아스팔트 콘크리트의 공극률 추정 연구

나일호 ( Na Il-ho ),이성진 ( Lee Sung-jin ),윤지현 ( Yoon Ji-hyeon ),김광우 ( Kim Kwang-woo ) 한국농공학회 2018 한국농공학회논문집 Vol.60 No.6

The air-void is known to be one of the influencing factors for estimating long-term performance of asphalt concrete. Most of all, confirming air void or density of pavement layer is important for quality control of field compaction level of asphalt concrete pavement. In this study, a non-nuclear type non-destructive density gage (NDDG) was used to estimate compacted air-voids of asphalt pavement as a non-destructive test method. Asphalt concrete slab specimens were prepared using 6 types of asphalt mixes in laboratory (lab) for lab NDDG test. Four different base structure materials were used to find out if there were any differences due to the type of base structure materials. The actual air-voids and NDDG air-voids were measured from 6 asphalt concrete slabs. Four sections of field asphalt pavements were tested using the NDDG, and actual air voids were also measured from field cores taken from the site where the NDDG air-void was measured. From lab and field experimental tests, it was found that the air-voids obtained by NDDG were not the same as the actual air-voids measured from the asphalt concrete specimen. However, it was possible to estimate air voids based on the relationship obtained from regression analysis between actual and NDDG air voids. The predicted air-voids based on the NDDG air-voids obtained from 50mm depth were found to be reliable levels with R²≒0.9. Therefore, it was concluded that the air-voids obtained from NDDG could be used to estimate actual air-voids in the field asphalt pavement with a relatively high coefficient of determination.

[미발표] 철도 적용을 위한 아스팔트 바인더 특성 및 배합설계 기준 검토

나일호(Il-Ho Na),양재봉(Jae B. Yang),이성혁(Seong H. Lee),이진욱(Jin W. Lee),김광우(Kwang W. Kim) 한국철도학회 2012 한국철도학회 학술발표대회논문집 Vol.2012 No.10

아스팔트 콘크리트를 철도 분야에서 소음 및 진동저감 등의 목적으로 인해 적용한 선진국 사례들이 늘어나고 관련 연구들이 활발하게 진행 되고 있다. 이에 최근 국내에서도 아스팔트 콘크리트를 이용한 기술적 검토가 진행 중이다. 아스팔트 콘크리트의 철도적용을 위해서는 국내에서 생산되고 있는 바인더와 혼합물의 검토가 선행되어야 하고 철도 적용에 적합한 배합설계가 검토 되어야 한다. 따라서 본 연구에서는 국내에서 생산되고 있는 바인더 및 혼합물의 Stiffness 를 검토하고, 국외에서 제시한 철도적용 아스팔트 콘크리트 배합설계 기준과 비교하고자 하였다. Since the asphalt concrete (AC) base course under the railway is known to be useful for noise reduction and vibration attenuation, application of AC base is increasing in many advanced countries, in which many related studies are actively conducted and published. Currently, technical reviews for using asphalt concrete for railway are under progress in a few domestic research institutes. Review of binders and mixtures, which are manufactured in domestic markets, must be preceded for AC applications to railway. The suitability of various binders should be carefully investigated for railway applications. Therefore, this study was initiated to review stiffness of aforementioned material (binders & mixtures) and compare current domestic mix design with railway applications for mix design presented in overseas.

디지털수도계량기 원격검침을 위한 사물인터넷 통신성능 비교 평가

나일호 ( Na Ilho ),김성재 ( Kim Seongjae ),한금석 ( Han Keumseok ),성제인 ( Seong Jein ),안재찬 ( Ahn Jaechan ) 한국물환경학회 2022 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2022 No.-

아스팔트 혼합물의 골재 간극률 예측을 위한 기계학습 프레임워크

박혜민,나일호,김현환,지봉준,Hyemin Park,Ilho Na,Hyunhwan Kim,Bongjun Ji 한국지반신소재학회 2024 한국지반신소재학회 논문집 Vol.23 No.1

The Voids in the Mineral Aggregate (VMA) within asphalt mixtures play a crucial role in defining the mixture's structural integrity, durability, and resistance to environmental factors. Accurate prediction and optimization of VMA are essential for enhancing the performance and longevity of asphalt pavements, particularly in varying climatic and environmental conditions. This study introduces a novel machine learning framework leveraging ensemble machine learning model for predicting VMA in asphalt mixtures. By analyzing a comprehensive set of variables, including aggregate size distribution, binder content, and compaction levels, our framework offers a more precise prediction of VMA than traditional single-model approaches. The use of advanced machine learning techniques not only surpasses the accuracy of conventional empirical methods but also significantly reduces the reliance on extensive laboratory testing. Our findings highlight the effectiveness of a data-driven approach in the field of asphalt mixture design, showcasing a path toward more efficient and sustainable pavement engineering practices. This research contributes to the advancement of predictive modeling in construction materials, offering valuable insights for the design and optimization of asphalt mixtures with optimal void characteristics.