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The integration of local power generation units into integrated energy service providers (IESPs) can enable IESPs to realize optimal resource allocation and provide multiple energy services. We propose a bi-level model for IESPs participating in joint electricity and carbon peer-to-peer (P2P) markets. To reduce carbon emissions, we set up carbon capture equipment in IESPs to collect carbon dioxide for the synthesis of methane and methanol. Furthermore, we propose a P2P transaction mechanism based on carbon emission flow and build a bi-level model to achieve the collaborative optimization of IESPs and distribution system operators. Additionally, we utilize the alternating direction method of multipliers (ADMM) algorithm to protect the privacy of users in the P2P transaction process. Simulation results of a distribution network with multiple IESPs demonstrate that the proposed model reduces the overall carbon emissions, allocates part of the carbon emission responsibilities to loads, and reduces the carbon emission costs of P2P transaction participants. [ABSTRACT FROM AUTHOR]

The penetration of renewables on the demand side has recently attracted a large amount of attention. Its dual identity has an important impact on the competition between power producers and market dispatching. This study analyzed the participation of prosumers in the Nash–Cournot model for power market clearing. On this basis, we considered the uncertainty of renewable energy production, under which we used the distributionally robust optimization (DRO) model to produce a market equilibrium. Moreover, the Column-and-Constraint Generation algorithm was employed to solve the model. As a result, the impact of prosumers penetration and their production uncertainty on market equilibria was quantified and analyzed. Numerical simulations on an IEEE-30 bus system investigated the impact of the uncertainty of renewable energy output, the penetration level of wind power, and the demand level on the market equilibria. Test results demonstrate that the social welfare obtained from the proposed DRO model is 6.89% higher than that obtained from traditional robust optimization models. [ABSTRACT FROM AUTHOR]

This paper systematically investigated the roles of aging and bio-oil regeneration on the self-healing evolution behavior of pure asphalt and terminal blend (TB) rubberized asphalt within wide temperature range, which was expected to promote the applications of self-healing asphalt pavement, meanwhile to accelerate the sustainable disposal of local bio-oil and rubber wastes. The self-healing, flow and elastic recovery (ER) abilities of asphalts within wide temperature range and their relationship were traced through the dynamic shear rheometer based fatigue-healing-fatigue, frequency sweep and creep recovery tests. Results revealed that different effects of temperature on ER and flow abilities of aged or rejuvenated asphalts resulted in the complexity of self-healing evolution behavior. The proposed ER-flow self-healing theory clarified that the ER ability of aged asphalts led the self-healing process in viscoelastic region, and the flow ability dominated as temperature rose into viscous flow region; however, the flow ability of regenerated asphalts dominated the self-healing at all measured temperatures. The aging growth percentage and regeneration recovery percentage (%RR) based on four self-healing characteristic temperatures were proposed to quantify the influences of aging and regeneration on self-healing evolution behavior of asphalts. The climate aging imparted severer impact on the self-healing evolution behavior of pure asphalt than long-term aging, whereas caused less impact on that of TB asphalt. The aging impact on the self-healing evolution behavior of TB asphalt was smaller than that of pure asphalt. Inversely, the %RR of rejuvenated asphalts increased as the growth of bio-oil content, and reached the maximum when adding 4%wt. waste cooking oil residues. The bio-oil elicited the greater regeneration improvement of self-healing performance than petroleum-based rejuvenator. Overall, the bio-oil regeneration recovery of the self-healing evolution performance of aged asphalts was limited. [Display omitted] • The elastic recovery(ER)-flow self-healing theory was proposed and clarified. • ER of aged asphalts led self-healing in viscoelastic region, while flow dominated in viscous flow region. • Flow ability of regenerated asphalts dominated self-healing at all measured temperatures. • Regeneration recovery percentage based on four self-healing characteristic temperatures was proposed. • Bio-oil regeneration recovery of aged asphalts in self-healing evolution performance was limited. [ABSTRACT FROM AUTHOR]

Healing characteristics of asphalt lay a foundation for the wide applications of permanent roads. However, the decay pattern of asphalt healing ability in actual climate environments still remains unclear. Hence, the weather accelerated ageing (WAA) influence on the healing temperature sensitivity of several representative asphalts is systematically investigated in this paper. Results from fatigue-healing-fatigue (FHF) experiment show that the WAA and terminal blend crumb rubber (TBCR) modification impart pronounced impacts to the healing temperature sensitivity of asphalts. Notably, it is found that the aged asphalt has a healing inertia zone with low healing temperature sensitivity, in which the healing ability of asphalt is at a relatively low level. Furthermore, four kinds of various index temperatures are put forward as the evaluation indicators to quantitatively characterize the influence of WAA on the healing temperature sensitivity, i.e. inert extended temperature at healing rate curve, inert extended temperature at healing percentage curve, top healing temperature (THT) shift value and complete healing temperature range (CHTR) shift value. Moreover, the greater the WAA resistance of asphalt, the smaller the WAA influence on its healing temperature sensitivity. The WAA reduces the differences of healing temperature sensitivity among various asphalts. Lastly, the thermal stability and phase behavior investigations reveal that the molecular compositions and phase state transition (PST) of asphalt will be changed after WAA, eventually inducing the healing temperature shift and the appearance of healing inertia zone. Image 1 • Four index temperatures are proposed to evaluate the influence of weather accelerated ageing (WAA). • Terminal blend rubber modification impart pronounced influence on healing temperature sensitivity of asphalt. • Weather accelerated aged asphalt has an obvious healing inertia zone with very low healing temperature sensitivity. • The greater the WAA resistance of asphalt, the smaller the WAA influence on healing temperature sensitivity. • WAA reduces the differences of healing temperature sensitivity among various asphalts. [ABSTRACT FROM AUTHOR]

Virtual power plants (VPPs) represent an effective way to aggregate various distributed energy resources (DERs) to participate in the double auction market. Currently, the surge in DERs and associated data poses great challenges to the trust and data privacy of VPPs. Blockchain technology has emerged as a solution to enhance both trust and security in a VPP network. However, the VPP blockchains suffer from inference attacks and limited throughput. To this end, this study proposes an innovative privacy-preserving VPP double auction mechanism that can effectively address the problems of scalability and privacy breaches in the existing methods. First, a proof of comprehensive energy ratio based on auction blockchain, which considers the renewable energy source ratio of VPPs, is established. Second, a sharding consensus strategy is designed to select mining nodes and validate transactions, boosting the efficiency and scalability of the blockchain during the auction. Third, the Rényi differential privacy and Dirichlet differential privacy are used separately to preserve sensitive data in the auction and consensus node election processes. The proposed method is verified by theoretical analysis and case studies, and the results demonstrate that the proposed model can improve the probability of mining rights and the income of VPPs with high renewable energy sources. Moreover, the privacy of VPPs can be preserved flexibly at a lower privacy cost by adjusting the privacy parameters. Finally, the computational efficiency of the auction blockchain is enhanced, and power consumption is saved by 54.64% on average. • We establish a proof of comprehensive energy ratio based auction blockchain. • We build a sharding consensus strategy to select mining nodes and validate transactions. • We introduce the Rényi differential privacy to preserve the bidding information of double auction. • We utilize the Dirichlet differential privacy to safeguard the privacy of node election data. [ABSTRACT FROM AUTHOR]

Asphalt rejuvenation technology is an effective method to recycle reclaimed asphalt pavement (RAP) for the production of high-quality recycled asphalt mixtures. This approach contributes to mitigating environmental pollution and facilitating resource recycling. In this study, the impact of rejuvenator molecules on the rejuvenation process was explored by utilizing theoretical models and dynamics simulations. Free volume theory models were used to calculate the diffusion coefficient, while molecular dynamics (MD) simulations revealed the internal energy changes during diffusion. Molecules with high interaction with aged asphalt are easier to reach the homogeneous state in diffusion systems under higher temperatures. The quantification of blending by Fick's 2nd law suggests that the blending process consists of three stages: an intense diffusion phase, a stabilization phase, and a homogeneous state phase. The time taken to reach the homogeneous stage depends on the chemical structure of the rejuvenators and the temperature. This study elucidates the molecular-scale mechanism of RAP rejuvenation and provides a roadmap for improving environmentally friendly RAP rejuvenation technology. • Blending process consists of three phases. • Interactions and free volume control the diffusion process. • Saturated-based molecules is more susceptible to high-temperature excitation. [ABSTRACT FROM AUTHOR]

Abstract Application of recycled concrete aggregate (RCA) in hot mix asphalt (HMA) is a sustainable alternative to natural aggregate. However, the increased asphalt consumption and decreased mechanical properties induced by the incorporation of RCA limit the extensive substitution of natural aggregates with RCA in HMA. In this paper, an experimental program was carried out to investigate the potential of recycled concrete aggregate pretreated with waste cooking oil residue (WCOR) with the expectation of reducing asphalt consumption and enhancing performance of HMA. The optimum pretreatment process for coarse and fine RCA in terms of content of WCOR, curing time and curing temperature was determined by an orthogonal design method and the grey correlation analysis. Subsequently, a laboratory characterization of HMA incorporating 40% coarse RCA, 40% coarse RCW (RCA pretreated with WCOR), 20% fine RCA and 20% fine RCW was further conducted in terms of optimum asphalt content, resistance to permanent deformation, cracking resistance at low temperature, fatigue performance, moisture sensitivity and dynamic modulus. Finally, scanning electron microscopy (SEM) test and fluorescence microscope (FM) test were performed to provide insight into the mechanism of WCOR-induced performance alteration. The experimental results showed that the pretreatment of RCA with WCOR decreased the optimum asphalt content from 5.4% to 4.5% for HMA incorporating 40% coarse RCA, from 5% to 4.5% for HMA incorporating 20% fine RCA. Moreover, RCA pretreated with WCOR enhanced significantly fatigue life and low temperature performance of HMA, while had a slight adverse effect on moisture sensitivity, permanent deformation resistance and dynamic modulus. Based on the SEM and FM tests, WCOR was observed to penetrate into tiny voids of cement mortar attached on RCA, which contributed to the reduction of optimum asphalt content and enhancement of fatigue life and low temperature performance of HMA. [ABSTRACT FROM AUTHOR]

Waste cooking oil residues (WCOR) based bio-asphalt is a potential substitute for petroleum asphalt. This study aims to prepare a bio-asphalt with high percentage of WCOR derived from esterification reaction for biodiesel. According to the uniform design results, the optimum mass ratios of materials were determined as WCOR of 33.3%, resin (RE-1) of 30.3%, hard asphalt particles (HAP) of 31.8%, low density polyethylene particles (LDPE) of 4.6% and linear SBS (L-SBS) of 4%. Based on the orthogonal design results, the WCOR based bio-asphalt would have the best performance when stirred for 40 min and sheared for 50 min (4000 rpm) under the condition of 170 °C with the optimum mass ratios. Rotational viscosity (RV) test results indicated that the viscosity of optimal bio-asphalt (OBA) was between PEN 70 base asphalt (PEN 70) and SBS modified asphalt (SBS-MA). Dynamic shear rheometer (DSR) test and bending beam rheometer (BBR) test results proved that OBA exhibited excellent high-temperature performance similar with SBS-MA, and it had superior low-temperature performance to SBS-MA and PEN 70. Furthermore, the effect of thermo-oxidative aging on the properties of OBA was studied. DSR test results revealed that the complex modulus and phase angle of thin film oven (TFO)-aged OBA both increased with the elevated aging level, indicating an increase in viscosity during aging process. Fourier transform infrared spectroscopy (FTIR) test results showed that there was no obvious variation on the functional groups of OBA after 15 h TFOT aging process. It was confirmed that less aging susceptibility of OBA was found compared with PEN 70, which demonstrated that OBA had a better aging resistance performance. [ABSTRACT FROM AUTHOR]

In this study, the correlation between low-temperature performance of the crumb rubber modified asphalt (CRMA) binders and their chemical fractions was investigated. The low-temperature properties of CRMA binders were firstly characterized by creep stiffness and creep rate using the bending beam rheometer (BBR) test. Secondly, the SARA fractions, namely saturates, aromatics, resins, and asphaltenes, were separated from CRMA binders using an improved column chromatography method. Meanwhile, the functional groups and the derived indexes of CRMA binders and SARA fractions were characterized using Fourier transform infrared (FTIR) spectra, respectively. Finally, statistical modeling was conducted between low-temperature properties and functional groups of CRMA binders and their SARA fractions. The results showed SARA fractions from CRMA binders contained substances released from the partially degraded crumb rubber modifiers, indicated by the emergence of peaks at 1100 cm−1, 967 cm−1, and other wavenumbers in FTIR spectra. The substance exchanges played a positive role in improving the low-temperature performance of CRMA binders. Meanwhile, the addition of crumb rubber could effectively inhibit the increase of polar functional groups in the aging process, such as carbonyl of aromatics, resins, and asphaltenes fractions. This thus significantly resisted the aging and improved the low-temperature performance of CRMA binders. Finally, the statistical modeling showed the stiffness modulus and creep rate of CRMA binders were highly correlated with functional groups of aromatics, resins and asphaltenes. This indicated that SARA fractions significantly affected the low-temperature properties of CRMA binders. [Display omitted] •SARA fractions were separated from CRMA binders using an improved column chromatography method. •FTIR spectra of base and CRMA binders as well as SARA fractions were compared. •Statistical modeling was conducted between the low-temperature properties of CRMA binders and functional groups of their SARA fractions. [ABSTRACT FROM AUTHOR]

Asphalt aging and fatigue cracking are common forms of distresses in flexible pavements. Microencapsulated rejuvenator has been generating significant interest in the feasibility and potentiality applications of asphalt materials self-healing over the past decade and is likely to remain so for the foreseeable future. Despite multiple attempts, the prerequisite is crack propagation through the microcapsules and resulting in the broken shell, which is a passive release. Strategies toward self-healing of uncracked aged asphalt by microcapsules remain a significant challenge. Herein, numerous successful applications of controlled release microcapsules in other fields, including biomedical engineering, food industry, agriculture, smart coating, textile industry, and cosmetics, are classified and referenced. Special attention is given to the mechanisms of release and their triggers, followed by recent advances of microencapsulation technologies with detailed experimental demonstrations. In particular, the challenges and promising solutions of novel controlled release systems for asphalt materials are proposed in detail for the first time. This review aims to present future directions for research in this field, which provides new ideas for the smart maintenance of asphalt pavements. [ABSTRACT FROM AUTHOR]

As the main source of traffic noise, tire-pavement noise poses a major threat to human health. Reducing tire-pavement noise influences of quality of life has recently drawn increasing attention. Quiet asphalt pavement provides an effective method to reduce tire-pavement noise and achieves economic, social and environmental benefits, due to take advantage of the existing infrastructure and combines the function of reducing noise. Tire-pavement noise generation mechanisms, tire-pavement noise measurement methods, the noise reduction mechanism of pavement, and some common and novel quiet asphalt pavement are reviewed in this paper. The paper reveals that tire air-pumping noise is the main source of tire-pavement noise. The existing tire-pavement noise measurement methods need to be further perfected to improve the accuracy of measurement results. All quiet asphalt pavements have good noise reduction performance, but each has its suitable range of applications. The purpose of this review is to provide reference and guidance for researchers to measure the tire-pavement noise, design quiet asphalt pavement, and select suitable quiet pavement according to the local conditions. [ABSTRACT FROM AUTHOR]