Field performance comparison of asphalt crack-filling materials: hot pour versus cold pour

2007 ◽  
Vol 34 (4) ◽  
pp. 505-512 ◽  
Author(s):  
Yetkin Yildirim

One of the most important components of pavement maintenance has been the sealing of cracks. The most commonly used materials for crack sealing are hot-pour sealants, such as hot rubber asphalt. However, this material can be hazardous at high operating temperatures and is more likely to be picked up by vehicle tires if the sealant is not sufficiently adhered to the pavement. Thus, cold-pour sealants have been considered as an alternative for crack sealing purposes. This study aims to compare the performance of hot-pour rubber asphalt crack sealant and cold-pour asphalt emulsion crack sealant in five different Texas districts that experience different weather conditions. The comparison includes seven different crack sealants: three cold pour and four hot pour. Five different roads in five districts were selected for comparison of the sealants. The field study results indicate that hot-pour sealants performed better than cold-pour sealants.Key words: sealants, emulsified crack sealants, crack sealing, asphalt pavements.


Author(s):  
Momen Mousa ◽  
Mostafa A. Elseifi ◽  
Mohammad Bashar ◽  
Zhongjie Zhang ◽  
Kevin Gaspard

One of the most common methods used to treat longitudinal and transverse cracks is crack sealing (CS), which is categorized as a preventive maintenance method. Field performance and cost-effectiveness of this treatment widely vary depending on pavement conditions and installation of the material. The objective of this study was to evaluate the field performance and cost-effectiveness of CS in flexible and composite pavements in hot and wet climates such as Louisiana, and to develop a model that would quantify the expected benefits of CS given project conditions. To achieve this objective, 28 control sections that were crack-sealed between 2003 and 2010 were monitored for at least four years. These sections included flexible and composite pavements, sealed and unsealed segments, and varying traffic levels. The performance of these sections was evaluated for the random cracking index (RCI) and roughness index (RI). Based on the results of this analysis, it was concluded that CS only has a significant impact on random cracking. When compared with untreated segments, CS extended pavement service life (PSL) by two years. When compared with the original pavement, CS extended PSL by 5.6 and 3.2 years for flexible and composite pavements, respectively, if applied at the correct time. The cost-benefit analysis indicated that CS is cost-effective whether asphalt emulsion or rubberized asphalt sealant is used. A non-linear regression model was developed to predict the extension in PSL because of CS without the need for performance data based on the average daily traffic (ADT), pavement type, and prior pavement conditions.



Author(s):  
Zhongyu Yang ◽  
Xinyi Zhang ◽  
Yichang (James) Tsai ◽  
Zhaohua Wang

Crack sealing is one of the most commonly used methods to preserve asphalt pavements. However, quantification of crack sealing benefits (or the long-term delaying effects of crack sealing on crack propagation) remains unavailable because field crack lengths could not be measured accurately and efficiently. In this study, 3D laser technology is proposed to measure and compare the growth of crack lengths between sealed and non-sealed pavement sections and, for the first time, to accurately and efficiently quantify the crack sealing benefits. To validate the proposed method and find adequate treatment timing (or conditions), nine field sites in Georgia, U.S., with different pavement pre-treatment conditions and roadway environmental factors were monitored over 3 years from December 2016 to September 2019. The study results showed that crack sealing can retard crack growth by 40%–128%, and such delaying effects are more significant under better pavement pre-treatment conditions. The findings suggest that transportation agencies can prolong the service life of pavements by applying crack sealing before the pavement condition becomes poor. In addition, this work has been proved to be very valuable for transportation agencies to determine the best timing and treatment criteria for crack sealing.



Author(s):  
Mohammed Sawalha ◽  
Hasan Ozer ◽  
Imad L. Al-Qadi ◽  
Hengxiao Xue

Crack sealing is a maintenance technique commonly used for cracks and joints to prevent moisture infiltration into pavements. Crack sealing materials should possess adequate adhesive and cohesive properties to remain intact in the cracks or joints, depending on the environment and pavement conditions in which they are installed. Adhesion failure is the most common failure mechanism and occurs mostly because of the poor adhesion capacity of sealants as well as the installation quality. Various standard laboratory tests are currently used to evaluate the adhesive properties of sealants to predict their field performance. These tests, however, either lack correlation with the field performance or have not yet been validated. This paper introduces the development of an adhesive prediction test: the modified crack sealant adhesion tester (modified CSAT). The modified CSAT is an improved version of the existing CSAT standard (AASHTO TP 89) and showed consistent results between specimens with sufficient repeatability. In addition, the modified CSAT was successful in capturing the effect of temperature changes and aging on the adhesion capacity of sealants. The adhesion test results were compared with the performance of the same sealants installed at different test sites. The correlation between the adhesion loads obtained in the laboratory was consistent with the sealant field performance.



2020 ◽  
pp. 57-62
Author(s):  
Olga Yu. Kovalenko ◽  
Yulia A. Zhuravlyova

This work contains analysis of characteristics of automobile lamps by Philips, KOITO, ETI flip chip LEDs, Osram, General Electric (GE), Gtinthebox, OSLAMPledbulbs with H1, H4, H7, H11 caps: luminous flux, luminous efficacy, correlated colour temperature. Characteristics of the studied samples are analysed before the operation of the lamps. The analysis of the calculation results allows us to make a conclusion that the values of correlated colour temperature of halogen lamps are close to the parameters declared by manufacturers. The analysis of the study results has shown that, based on actual values of correlated colour temperature, it is not advisable to use LED lamps in unfavourable weather conditions (such as rain, fog, snow). The results of the study demonstrate that there is a slight dispersion of actual values of luminous flux of halogen lamps by different manufacturers. Maximum variation between values of luminous flux of different lamps does not exceed 14 %. The analysis of the measurement results has shown that actual values of luminous flux of all halogen lamps comply with the mandatory rules specified in the UN/ECE Regulation No. 37 and luminous flux of LED lamps exceeds maximum allowable value by more than 8 %. Luminous efficacy of LED lamps is higher than that of halogen lamps: more than 82 lm/W and lower power consumption. The results of the measurements have shown that power consumption of a LED automobile lamp is lower than that of similar halogen lamps by 3 times and their luminous efficacy is higher by 5 times.



Author(s):  
Biao Ma ◽  
Yongping Hu ◽  
Fangshu Liu ◽  
Wei Si ◽  
Kun Wei ◽  
...  


Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2548 ◽  
Author(s):  
Yanhai Yang ◽  
Ye Yang ◽  
Baitong Qian

Cold recycled mixes using asphalt emulsion (CRME) is an economical and environmentally-friendly technology for asphalt pavement maintenance and rehabilitation. In order to determine the optimum range of cement contents, the complex interaction between cement and asphalt emulsion and the effects of cement on performance of CRME were investigated with different contents of cement. The microstructure and chemical composition of the fracture surface of CRME with different contents of cement were analyzed in this paper as well. Results show that the high-temperature stability and moisture susceptibility of CRME increased with the contents of cement increasing. The low-temperature crack resistance ability gradually increased when the content of cement is increased from 0% to 1.5%. However, it gradually decreased when the content of cement is increased from 1.5% to 4%. Cold recycled mixes had better low-temperature cracking resistance when the contents of cement were in the range from 1% to 2%. The results of microstructure and energy spectrum analysis show that the composite structure is formed by hydration products and asphalt emulsion. The study will be significant to better know the effects of cement and promote the development of CRME.





Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 483
Author(s):  
Tomasz Czarnecki ◽  
Kacper Bloch

The subject of this work is the analysis of methods of detecting soiling of photovoltaic panels. Environmental and weather conditions affect the efficiency of renewable energy sources. Accumulation of soil, dust, and dirt on the surface of the solar panels reduces the power generated by the panels. This paper presents several variants of the algorithm that uses various statistical classifiers to classify photovoltaic panels in terms of soiling. The base material was high-resolution photos and videos of solar panels and sets dedicated to solar farms. The classifiers were tested and analyzed in their effectiveness in detecting soiling. Based on the study results, a group of optimal classifiers was defined, and the classifier selected that gives the best results for a given problem. The results obtained in this study proved experimentally that the proposed solution provides a high rate of correct detections. The proposed innovative method is cheap and straightforward to implement, and allows use in most photovoltaic installations.



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