Economic Effects of Microsurfacing on Thermally-Cracked Pavements

Abraham Bae,Shelley M. Stoffels 대한토목학회 2008 KSCE JOURNAL OF CIVIL ENGINEERING Vol.12 No.3

The exclusive effects of microsurfacing on thermal cracks were quantified in terms of IRI. In addition, vehicle operating costsrelated to the IRI were estimated. For the MnROAD project, using a measurement device with high resolution, pavement surfaceswith thermal cracks were profiled before and after microsurfacing. The crack profiles were transferred into longitudinal profiles withno cracks so that the exclusive contribution of original and microsurfaced cracks to roughness could be analyzed. Then, vehicleoperating costs corresponding to the exclusive roughness were evaluated. Applying the given amount of microsurfacing materials,the IRI resulting from cracks with 0.7 cm depth and 0.58 m width was reduced by about 80 percent for serviceable roughness levels.1.8 cm depth and 0.80 m width were decreased by about 60 percentand about 45 percent, respectively. By examining vehicle operating costs, it was found that a small difference in crack severitiesresults in a greater increase in cost. Therefore, it was concluded that prompt operation of microsurfacing for any crack severity levelsis no less important than earlier operation for low severity cracks. In addition, it was concluded that microsurfacing can be a cost-effective maintenance technique for cracks for a year. If more than 3 cracks would be detected in the field, microsurfacing would bestill a cost-effective maintenance method for any severity crack level.

An approach to incorporate amplitudes and wavelengths of transverse crack for predicting IRI

Abraham Bae,Benjamin Worel 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.12

A methodology was proposed that can improve pavement smoothness prediction. As an initial attempt, smoothness due to solely transverse cracking was investigated. The new model incorporated amplitudes and wavelengths of transverse crack which are directly related to IRI computation. The crack amplitude and wavelength were measured by automated profiler from the MnRoad test roads and formulized with mathematical form expressed with respect to various crack depths and widths, respectively. Instead of conventional severity criteria, crack severities could be determined by crack depth and width in the mathematical form. Utilizing digital signal processing techniques, cracked surfaces with various severities were successfully prepared. The computed IRI values were found to be significantly related to crack severities expressed by width and depth. Then, an IRI prediction model was derived containing the simulated various crack severities and crack occurrences. Ultimately, the IRI model was validated using transverse crack performance data from MnRoad. The model incorporated spectral information that could fundamentally and accurately predict IRI increment by crack. This confirmed the necessity of incorporation of amplitude and wavelength information in predicting IRI.

Paver Sensor System Performances on the Initial Smoothness of HMA Pavement

Bae Abraham,Lee Hae Sung,Jung Dae Jin 한국도로학회 2018 한국도로학회논문집 Vol.20 No.5

PURPOSES: The performance of both string line and multi-sonic sensor systems were investigated with respect to achieving smoothness in a 5 cm-thick Stone Mastic Asphalt (SMA) wearing layer. METHODS: String line and multi-sonic sensor systems were applied in the leading and trailing lanes, respectively, with two-lane simultaneous paving. RESULTS: Two systems did not show any significant statistical difference in initial International Roughness Index(IRI). The multi-sonic sensor system produced smoothness similar to that by the string line system. CONCLUSIONS : The string line system was found to be very effective in eliminating roughness below a wavelength of about 2 m, confirming that a string line reference is the best system to obtain a smoother surface. A multi-sonic sensor system evidently demonstrated the capability of replicating a reference level and, partly showed a roughness averaging effect within the system length. It can further be concluded that the effect of smoothness of the underlying layer on the upper layer smoothness cannot be ignored.

3D-Engineered Technique Methodology Development for Thickness Quality Control of Bridge Overlay Paving

Bae Abraham,Jeong Juyong,Park Byungyck 한국도로학회 2018 한국도로학회논문집 Vol.20 No.5

PURPOSES: A methodology using a 3D-engineering technique was developed for implementation in paving Quality Control (QC) practice in bridge overlay paving. METHODS: The as-built surface of a concrete-box-girder bridge tends to exhibit a certain level of undulation or roughness. This is usually caused by the inevitable limitation that camber prediction and construction cannot be perfectly matched. The undulation itself would not be a severe defect in a bridge structure, but it results in a challenge for achieving overlay pavement qualities such as pavement thickness and smoothness. One advantage of the 3D-engineering technique is that it allowed identification in advance, of conditions that will interfere with construction, thus preventing non-conformance qualities from being re-worked. RESULTS : Utilizing this technique, overlay paving was virtually simulated in advance, and insufficient thickness areas and rough sections were visually identified. Paving quantities were automatically computed. Paving level alternatives were correspondingly established based on analysis of the quantitative and 3D visual outputs. CONCLUSIONS: This study showed that this methodology could be successfully utilized for optimizing paving quantity and quality

Evaluation of Pavement Subgrade Long-term Equilibrium Moisture with Suction Potential

Abraham Bae,Shelley M. Stoffels 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.1

The objective of this study was to find the relationship between soil suction potential and moisture change from the Optimum Moisture Content (OMC) to the long-term equilibrium moisture. The sixty-five Seasonal Monitoring Program (SMP) sites in the Long Term Pavement Performance (LTPP) program were employed. Suction potential was evaluated using the Soil Water Characteristic Curve (SWCC) characterized. Moisture change wetting and drying from OMC was identified. Maximum wetting moistures are 15.3 and 19.9 percent from OMC and maximum drying moistures are -10.3 and -15.4 percent from OMC for flexible and rigid pavements, respectively. Once reaching equilibrium, the moisture variations were mostly less than 1 percent in terms of gravimetric moisture. OMC has a significant correlation to the percentage passing at 0.02 mm sieve size. As suction potential increased, subgrade became more wetted. The characteristic was more noticeable in rigid than flexible pavements. Groundwater table and precipitation were found not to be dominant factors in causing long-term moisture changes.

Smoothness Improvement by HMA Overlay on Very Rough Surface in Urban Tunnel Expressway

Abraham Bae,David Lee,Jun Yew Tan 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.6

This study reveals new findings on pavement smoothness improvement characteristics of HMA overlay on very rough concrete base slab surface that has not been previously investigated. International Roughness Index (IRI) measurements were conducted in an urban open-cut tunnel expressway. Overlay design is two HMA lifts of 4 cm-thick each. For concrete slab surface with 6.0 to 9.5 m/ km of IRI, less than 1.6 m/km of post-overlay IRI was achieved in all 30 sections with 100 m interval, and less than 1.0 m/km IRI was obtained in about 53% sections. For about 30% of the sections, 2.0 m/km IRI was accomplished even in the 1st lift overlay. In wide range of IRI including up to 9 m/km, it was concluded that smoother pre-overlay surface produces smoother post-overlay surface. Post-overlay IRI is about 20% of pre-overlay IRI, but with large variation. Rather, the relationship between ΔIRI and preoverlay IRI has higher statistical significance. By validation process, it was concluded that smoothness prediction with respect to ΔIRI is more reliable than IRI value itself. This characteristic was found to be more evident when roughness is evaluated with respect to detailed wavelengths.

Pavement Roughness Index Impact for Specific Wavebands and Causative Factors

Abraham Bae,Shelley M. Stoffels 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.5

This study quantified roughness for individual wavebands in the long wavelength range in pavement longitudinal profiles. Particularly, the roughness was related with quantified plausible factors associated with those wavebands. Root Mean Square (RMS) roughness defined under the Power Spectral Density (PSD) profile in the frequency domain was used as a quantified index that can reflect detailed roughness information for a specific waveband. A method to interpret the quantified roughness in terms of the International Roughness Index (IRI) was also developed. It was demonstrated that the RMS roughness evaluated in individual wavebands under the PSD function can be technically interpreted in terms of IRI. Thus, the interpreted IRI could be directly explained by the quantified plausible factors. It was concluded that the demonstrated method can contribute to improved roughness prediction models the Mechanistic-Empirical Pavement Design Guide (MEPDG) with smoothness characteristics in detailed wavelengths underpinnings in future generations of pavement design models.

잔디기생선충에 대한 살선충 약제의 살선충 효과

나희빈(Hee-been Na),Abraham Okki Mwamula,배은지(Eun-Ji Bae),이동운(DongWoon Lee) 한국잡초학회·한국잔디학회 2021 Weed & Turfgrass Science Vol.10 No.1

잔디에는 다양한 식물기생선충들이 피해를 주고 있지만 우리나라의 경우 등록되어 있는 살선충제가 없다. 이에 본 연구는 골프장 잔디에 발생하는 식물기생선충에 대한 효과적인 살선충제를 알아보기 위하여 살선충제(abamectin, fluazaindolizine, fluopyram, fosthiazate, imicyafos)와 neem oil, 미생물 살선충제(Burkholderia rinojensis), 농업용 과산화수소수 제품을 이용하여 실내와 야외에서 실험을 수행하였다. 5종의 선충(Paratrichodorus minor, Helicotylenchus microlobus, Paralongidorus koreanensis, Mesocriconema curvatum, Tylenchorhynchus thermophilus)이 혼재하여 발생하는 서경타니골프장 토양시료와 두 종의 선충(H. microlobus, M. curvatum)이 혼재하는 스카이72 골프장 토양시료에서 분리한 선충들을 이용하여 실내 살선충 활성 검정 결과 과산화수소수와 fluopyram의 활성이 높았고, 이들 두 물질에 선충 침지 시 3시간에도 80%이상의 치사율을 보였다. 켄터키블루그래스로 조성된 골프장 티에서 살선충물질(B. rinojensis, fluazaindolizine, fluopyram, imicyafos, 과산화수소수)들의 효과를 시험한 결과 imysiafos와 fluapyram의 효과가 처리 60일째까지 높게 나타나 이들 두 살선충제의 경우 골프장 선충 방제에 실용적 활용이 가능 할 것으로 사료된다. Various species of plant parasitic nematodes are known to damage turfgrass. However, there are no nematicides registered for the control of turfgrass nematodes in Korea. Therefore, the present study was conducted to investigate the efficacy of some nematicidal active ingredients ([nematicides; abamectin, fluazaindolizine, fluopyram, fosthiazate, imicyafos], microbial nematicide [Burkholderia rinojensis], and nematicidal compound [hydrogen peroxide]) on turfgrass nematodes, for the subsequent selection and development of effective nematicidal agents. As a result of the laboratory nematicidal activity test, high efficacy of hydrogen peroxide and fluopyram against mixed nematode populations of 5 species (Paratrichodorus minor, Helicotylenchus microlobus, Paralongidorus koreanensis, Mesocriconema curvatum, and Tylenchorhynchus thermophilus) isolated from the Seogyeong Tani and Sky72 golf course soil samples were observed. Treatment of the nematodes with the two chemical compounds exhibited high mortality rate of more than 80% even in the first 3 hours after treatment, depending on the chemical concentration. In field treatments on golf course tees (Kentucky bluegrass), imicyafos and fluopyram were more effective until the 60th day of treatment. Therefore, it is considered that these two nematicides can be practically used to control nematodes in golf courses.

낙동강 델타지역 지반의 비동결 및 동결상태 열전도도 평가

박상영(Park, Sangyeong),황채민(Hwang, Chaemin),손영진(Son, Youngjin),배석일(Bae, Abraham),최항석(Choi, Hangseok) 대한토목학회 2022 대한토목학회 학술대회 Vol.2022 No.10

Intersystem Fault가 AC/DC 하이브리드 전력망에 미치는 영향 분석

김종명(Jong-Myoung Kim),송진솔(Jin-Sol Song),배승환(Seung-Whan Bae),아브라함(Abraham D. Arefaynie),메흐디(Mehdi Arif),핫산(Hassan S Jarjees UL),김철환(Chul-Hwan Kim) 대한전기학회 2022 대한전기학회 학술대회 논문집 Vol.2022 No.10