Refined decomposition: A new separation method for RAP materials and its effect on aggregate properties

Yu, Xin; Tang, Wei; Li, Ning; Jiang, Mengmeng; Huang, Jiandong; Wang, Deyu

doi:10.1016/j.conbuildmat.2022.129452

Cited by 24 publications

(11 citation statements)

References 23 publications

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“…The combination of Tables 3-5 and Figure 6 shows that for the RAM containing 50% RAP, the curve of the RAM-FR was significantly narrower than that of the RAM-UR, implying that the dispersion of road performance test results for the RAM-FR became lower. This indicates that the road performance variability of the RAM can be effectively controlled by the fractionation process of RAP material [38]. Compared with the curves of the RAM-UR, the curves of the RAM-FR showed a significant forward shift, indicating that the road performance of the RAM can be improved by controlling the variability.…”

Section: Analysis Of the Variability In Road Properties For Recycled ...mentioning

confidence: 88%

Effect of Fractionation Process and Addition of Composite Crumb Rubber-Modified Asphalt on Road Performance Variability of Recycled Asphalt Mixtures with High Reclaimed Asphalt Pavement (RAP) Content

Wei,

Ji,

Song

et al. 2023

Buildings

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The application of reclaimed asphalt pavement (RAP) can help reduce resource waste and environmental pollution in road construction. However, so far, only a small percentage of RAP materials can be used in road construction. The key obstacles to the application of a recycled asphalt mixture (RAM) with high RAP content are the variability of RAP materials and the difficulty of fully rejuvenating aged asphalt. However, there is still a lack of research on the effect of the variability of RAP materials and recycled asphalt on the quality control of a RAM. Therefore, this study investigates the effects of sieve pretreatment of RAP material using 4.75 mm sieve mesh and the use of composite crumb rubber-modified asphalt (CCRMA) to reclaim aged asphalt on the road performance and frame variability of reclaimed asphalt mixtures. Therefore, this study investigates the effects of the fractionation process of RAP material using 4.75 mm sieve mesh and the use of CCRMA to reclaim aged asphalt on the road performance of a RAM. The results show that the fractionation process can effectively reduce the mitigation of RAP agglomeration and reduce the variability of gradation, which in turn reduces the variability of road performance. The incorporation of CCRMA can effectively improve the high-temperature stability performance and low-temperature cracking resistance. The dynamic stability and the fracture energy of the CRAM (RAM prepared using CCRMA) were four and one and a half times as large as that of the NAM (RAM prepared using base asphalt), respectively. The fractionation process of RAP material and the utilization of CCRMA could help reduce the variability of the RAM while improving the road performance of the RAM.

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Section: Analysis Of the Variability In Road Properties For Recycled ...mentioning

confidence: 88%

Effect of Fractionation Process and Addition of Composite Crumb Rubber-Modified Asphalt on Road Performance Variability of Recycled Asphalt Mixtures with High Reclaimed Asphalt Pavement (RAP) Content

Wei,

Ji,

Song

et al. 2023

Buildings

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“…In order to ensure the quality of recycled asphalt mixtures, the general plant-mixed thermal regeneration requires a ratio of RAP addition of 15% to 30% [8][9][10]. For this reason, researchers have proposed asphalt and mineral separation techniques, including physical refined separation methods [11][12][13],…”

Section: Introductionmentioning

confidence: 99%

The Effect of Refined Separation on the Properties of Reclaimed Asphalt Pavement Materials

Wang,

Dou,

Wang

et al. 2024

Buildings

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Refined separation not only controls the variability of reclaimed asphalt pavement (RAP), but also improves the mixing ratio of RAP and the quality of recycled asphalt mixtures. This study examines RAP treated with various refined separation frequency parameters, analyzes the variation rules and the variability of RAP aggregate gradation, asphalt content, asphalt properties, and aggregate properties, and calculates the maximum mixing percentage of coarse RAP material by using the gradation variability control method and the asphalt content variability control method. The results show that the variability of gradation and asphalt content of coarsely separated RAP is considerable, and a refined separation process significantly reduces the variability of gradation and asphalt content of RAP; the agglomeration of RAP decreases with an increase in the refined separation frequency; and the RAP agglomeration of three kinds of RAPs (E1, E2, and E3) under a refined separation frequency of 55 Hz reduces by 6.40%, 4.30%, and 4.30%, respectively, as compared with that of coarsely separated RAPs. The asphalt content of the refined separation RAP gradually decreases with an increase in frequency, and the asphalt content of E1 and E2 (55 Hz) was only 0.95% and 1.10%, respectively. The maximum percentage of RAP in recycled asphalt mixtures was calculated using the gradation variability control method and the asphalt content variability control method, respectively. The maximum proportions of RAP were 45% and 33% for A1 (0 Hz), respectively, and the maximum proportions of RAP for E1 (55 Hz) were all 100%. The results of the two methods show that the process of refined separation can increase the maximum proportion of blended RAP materials. They also demonstrate that the refined separation process can increase the maximum blending ratio of coarse RAP materials, thereby improving the quality of the RAP, increasing the proportion of RAP blending, and ensuring the quality of the recycled asphalt mixture. In conclusion, the refined separation process holds promise for maximizing the potential value of RAP and optimizing its recycling, environmental, and economic benefits.

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“…With the development of artificial intelligence, machine learning models have attracted more and more attention from civil engineers because of their high prediction accuracy and high prediction efficiency [31,32], and have been successfully applied to the prediction of concrete strength [33][34][35][36][37]. Hoang et al [38] proposed using Gaussian Process Regression (GPR) to simulate the mechanical properties of high-performance concrete (HPC) and compared the prediction effect of GPR with the prediction models of least squares support vector machines and artificial neural networks.…”

Section: Introductionmentioning

confidence: 99%

Potential of Repurposing Recycled Concrete for Road Paving: Flexural Strength (FS) Modeling by a Novel Systematic and Evolved RF-FA Model

Gu¹,

Shen

Pang

et al. 2023

Sustainability

Self Cite

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Concrete can be recycled after certain processing technologies for use in pavement engineering but the flexural strength (FS) is difficult to predict accurately in the design process. This study proposes a novel systematic and evolved approach to estimate the FS of recycled concrete. The proposed methods are conducted based on the random forest (RF) model as well as the firefly algorithm (FA), where the latter is employed to tune the hyperparameters of the RF model. For this purpose, data sets were collected from previously published literature for the training and verification of the model, and the accuracy of the model was verified by the fitting effect of the predicted and actual values. The results showed that the proposed hybrid machine learning model has a good fitting effect on the predicted and actual values; the calculation and evaluation process demonstrated fast convergence and significantly lower values of RMSE for the proposed model to determine the FS of the recycling concrete. In addition, the study analyzed the sensitivity of the FS of recycled concrete to input variables, and the results showed that effective water-cement ratio (WC), water absorption of recycling concrete (WAR), and water absorption of natural aggregate (WAN) show more obvious influences on FS, so these factors should be paid more attention in future pavement design using the recycling of concrete.

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Refined decomposition: A new separation method for RAP materials and its effect on aggregate properties

Cited by 24 publications

References 23 publications

Effect of Fractionation Process and Addition of Composite Crumb Rubber-Modified Asphalt on Road Performance Variability of Recycled Asphalt Mixtures with High Reclaimed Asphalt Pavement (RAP) Content

Effect of Fractionation Process and Addition of Composite Crumb Rubber-Modified Asphalt on Road Performance Variability of Recycled Asphalt Mixtures with High Reclaimed Asphalt Pavement (RAP) Content

The Effect of Refined Separation on the Properties of Reclaimed Asphalt Pavement Materials

Potential of Repurposing Recycled Concrete for Road Paving: Flexural Strength (FS) Modeling by a Novel Systematic and Evolved RF-FA Model

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