Performance characterization and enhancement mechanism of recycled asphalt mixtures involving high RAP content and steel slag

Mini-Review on the Application of Nanomaterials in Improving Anti-Aging Properties of Asphalt

Sustainable and resilient pavement infrastructure is critical for current economic and environmental challenges. In the past 10 years, the pavement infrastructure strongly supports the rapid development of the global social economy. New theories, new methods, new technologies and new materials related to pavement engineering are emerging. Deterioration of pavement infrastructure is a typical multi-physics problem. Because of actual coupled behaviors of traffic and environmental conditions, predictions of pavement service life become more and more complicated and require a deep knowledge of pavement material analysis. In order to summarize the current and determine the future research of pavement engineering, Journal of Traffic and Transportation Engineering (English Edition) has launched a review paper on the topic of “New innovations in pavement materials and engineering: A review on pavement engineering research 2021”. Based on the joint-effort of 43 scholars from 24 well-known universities in highway engineering, this review paper systematically analyzes the research status and future development direction of 5 major fields of pavement engineering in the world. The content includes asphalt binder performance and modeling, mixture performance and modeling of pavement materials, multi-scale mechanics, green and sustainable pavement, and intelligent pavement. Overall, this review paper is able to provide references and insights for researchers and engineers in the field of pavement engineering.

New innovations in pavement materials and engineering: A review on pavement engineering research 2021

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Chemical characterizations and molecular dynamics simulations on different rejuvenators for aged bitumen recycling

Enhanced induction heating and self-healing performance of recycled asphalt mixtures by incorporating steel slag

Multi-scale performance evaluation and correlation analysis of blended asphalt and recycled asphalt mixtures incorporating high RAP content

Recycling of reclaimed asphalt pavement (RAP) has gradually emerged as a hot topic in the current research of building materials. Manufacturing the recycled asphalt mixture with a high RAP content still remains a major challenge due to the problem of inferior water damage resistance and fatigue cracking resistance. The aim of this study is to evaluate the servicing performance of recycled asphalt mixture with high percentage of RAP and assess its environmental impact on volatile organic compounds (VOCs) emission. To further explore the intrinsic factor on the performance of a recycled asphalt mixture, the mixed asphalt binder with a different content of extracted RAP binder was firstly investigated. The results show that the larger the content of RAP binder, the lower the mechanical indexes and VOCs emission. There exists an internal relationship between the chemical composition and VOCs release behavior with the variation of the recycled asphalt binder content. Based on the results of mixed recycled asphalt binder, the road servicing performance of a rather high utilization of RAP (i.e., 50%, 60%, and 70%) was assessed. It was found that the reuse of RAP aggregates has little influence on the volume performance of recycled asphalt mixture, and servicing performances still meet the construction requirements in spite of a descending trend. Moreover, a significant reduction effect on VOCs emission was found in the mixing stage of recycled asphalt mixture, indicating that the VOCs emission can be decreased by 94.82% when the content of RAP aggregates increases to 70%. The recycling of RAP with a high content contributes to the sustainable development of road engineering and the construction of green pavements.

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Environmental Impact on VOCs Emission of a Recycled Asphalt Mixture with a High Percentage of RAP

Steel slag is the by-product of the steelmaking industry, the negative influences of which prompt more investigation into the recycling methods of steel slag The purpose of this study is to characterize steel slag filler and study its feasibility of replacing limestone filler in asphalt concrete by evaluating the resistance of asphalt mastic under various aging methods Firstly, steel slag filler, limestone filler, virgin asphalt, steel slag filler asphalt mastic and limestone filler asphalt mastic were prepared Subsequently, particle size distribution, surface characterization and pore characterization of the fillers were evaluated Finally, rheological property, self-healing property and chemical functional groups of the asphalt mastics with various aging methods were tested via dynamic shear rheometer and Fourier transform infrared spectrometer The results show that there are similar particle size distributions, however, different surface characterization and pore characterization in the fillers The analysis to asphalt mastics demonstrates how the addition of steel slag filler contributes to the resistance of asphalt mastic under the environment of acid and alkaline but is harmful under UV radiation especially In addition, the pore structure in steel slag filler should be a potential explanation for the changing resistance of the asphalt mastics In conclusion, steel slag filler is suggested to replace limestone filler under the environment of acid and alkaline, and environmental factor should be taken into consideration when steel slag filler is applied to replace natural fillers in asphalt mastic

https://www.mdpi.com/1996-1944/14/4/869/pdf

Characterization of Steel Slag Filler and Its Effect on Aging Resistance of Asphalt Mastic with Various Aging Methods.

Abstract Pueraria lobata var. montana (P. montana) belongs to the genus Pueraria and originated in Asia. Compared with its sister P. thomsonii, P. montana has stronger growth vigour and cold-adaption but contains less bioactive metabolites such as puerarin. To promote the investigation of metabolic regulation and genetic improvement of Pueraria, the present study reports a chromosome-level genome of P. montana with length of 978.59 Mb and scaffold N50 of 80.18 Mb. Comparative genomics analysis showed that P. montana possesses smaller genome size than that of P. thomsonii owing to less repeat sequences and duplicated genes. A total of 6,548 and 4,675 variety-specific gene families were identified in P. montana and P. thomsonii, respectively. The identified variety-specific and expanded/contracted gene families related to biosynthesis of bioactive metabolites and microtubules are likely the causes for the different characteristics of metabolism and cold-adaption of P. montana and P. thomsonii. Moreover, a graphic genome was constructed based on 11 P. montana accessions. Total 92 structural variants were identified and most of which are related to stimulus-response. In conclusion, the chromosome-level and graphic genomes of P. montana will not only facilitate the studies of evolution and metabolic regulation, but also promote the breeding of Pueraria.

Minghua Wei

Papers

Performance characterization and enhancement mechanism of recycled asphalt mixtures involving high RAP content and steel slag

Multi-scale performance evaluation and correlation analysis of blended asphalt and recycled asphalt mixtures incorporating high RAP content

Environmental Impact on VOCs Emission of a Recycled Asphalt Mixture with a High Percentage of RAP

Characterization of Steel Slag Filler and Its Effect on Aging Resistance of Asphalt Mastic with Various Aging Methods.

Chromosome-level and graphic genomes provide insights into metabolism of bioactive metabolites and cold-adaption of Pueraria lobata var. montana