Article
Green & Sustainable Science & Technology
Feipeng Xiao, Ling Xu, Zifeng Zhao, Xiangdao Hou
Summary: This paper synthesizes the applications and technologies of reclaimed asphalt pavement in China, covering the historic development, recycling technologies, mix design, and comprehensive performances. It also analyzes the feasibility of multi-cycle repeated recycling and discusses the life-cycle assessment. Furthermore, it introduces the combination of reclaimed asphalt pavement, innovative technologies, advanced materials and equipment.
SUSTAINABLE MATERIALS AND TECHNOLOGIES
(2023)
Review
Construction & Building Technology
Kavitha Karthikeyan, Saravanan Kothandaraman, Goutham Sarang
Summary: In the past decade, there has been an increasing interest in recycling materials from the construction sector due to their environmental benefits. One material that has gained importance is the Reclaimed Asphalt Pavement (RAP) from demolished flexible pavement. RAP has been experimented with as a potential replacement for pristine aggregates in concrete pavements. However, more efforts are needed to improve the strength of RAP-concrete and explore its full potential for sustainable concrete pavements.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2023)
Article
Construction & Building Technology
Edoardo Bocci, Emiliano Prosperi
Summary: Rubberized asphalt technology has been developed and applied in HMA production as a profitable solution to dispose of waste rubber and improve bitumen behavior. However, the recyclability of RARP into new HMA has not been solved. This study found that RARP can be recycled without negatively affecting HMA performance, with the use of a rejuvenating agent achieving similar mechanical behavior to a reference mix of only virgin components.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
K. Lakshmi Roja, Eyad Masad, Walaa Mogawer
Summary: This study aims to determine the optimal amount of Reclaimed Asphalt Pavement (RAP) that can be added to asphalt mixtures without negatively impacting fracture resistance. Through characterization and testing of asphalt mixtures with different RAP contents, it was recommended to use up to 20% RAP in asphalt mixtures based on performance results and binder content in Qatar.
ROAD MATERIALS AND PAVEMENT DESIGN
(2021)
Review
Environmental Sciences
Chad J. Spreadbury, Kyle A. Clavier, Ashley M. Lin, Timothy G. Townsend
Summary: This study reviewed the environmental risks associated with reclaimed asphalt pavement (RAP) management, specifically focusing on the leaching of metals and organic compounds. Using fate and transport models, it was found that most of the potential environmental concerns related to RAP leachate concentrations could be effectively attenuated under certain conditions. Understanding the variables that influence leaching and risk assessment is crucial for maximizing beneficial reuse of RAP while safeguarding human and environmental health.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Engineering, Environmental
Danning Li, Zhen Leng, Shaowei Zhang, Jiwang Jiang, Huayang Yu, Frohmut Wellner, Sabine Leischner
Summary: This study aims to investigate the mobilization tendency of aged AR binder during the recycling of RARP mixture, and found a positive correlation between the mobilization indexes and the cracking resistance of the RARP mixture.
RESOURCES CONSERVATION AND RECYCLING
(2022)
Article
Construction & Building Technology
Abraham A. Abe, Cesare Oliviero Rossi, Shahin Eskandarsefat, Michele Porto, Valeria Loise, Loretta Venturini, Paolino Caputo
Summary: With the global environmental crisis reaching a critical point, the demand for eco-friendly products like recycled asphalt pavement is increasing in the roadway industry. This study focuses on one of the key factors for successful asphalt pavement recycling - the recycling agents. Through various techniques and analyses, the study finds that rejuvenators have an advantage over fluxing agents in reversing the aging phenomenon in asphalt, which could significantly impact the durability and quality of recycled asphalt pavement.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Green & Sustainable Science & Technology
Hassan Ziari, Mojtaba Hajiloo, Pooyan Ayar
Summary: This study investigated the effect of adding recycling agents (RAs) at different locations in the manufacturing process of asphalt mixtures containing reclaimed asphalt pavement (RAP). The results showed that the optimal location for adding RAs varies depending on the type of RA used. Proper placement of RAs can improve the mechanical properties of asphalt mixtures containing RAP.
Article
Materials Science, Multidisciplinary
Min Dai, Chang-ming Chen, Zhan Wang, Wen-hao Pan, Xiao-wei Sun, Ning Tang, Li-mei Wu
Summary: This study investigated the blending degree between modified bitumen and RAP, utilizing a montmorillonite-rhodamine composite modifier as a tracer. Findings revealed the optimal heating temperature range, factors influencing the blending interface, and the thickness range of the interface transition zone between RAP and modified bitumen.
MATERIALS RESEARCH EXPRESS
(2022)
Article
Construction & Building Technology
Jing Xu, Hui Chen, Yong Wen, Bin Xue, Rui Li, Jianzhong Pei
Summary: This study found that adding recycling oils may impair the durability of asphalt binders with reclaimed asphalt materials, but have little effect on the chemical reaction (oxidation). There is a good correlation between rheological and chemical changes, but it is also influenced by the material dependency.
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
(2021)
Article
Green & Sustainable Science & Technology
Xiaoguang Yao, Yan Wang, Tao Xu
Summary: This study focuses on the development of new recycling, aging simulation, and regeneration methods of reclaimed SBS asphalt through optimizing centrifugation method for RAP, studying the relationship between asphalt performance indexes and aging duration, discussing regeneration methods, and revealing the regeneration mechanism. The developed methods show advantages in test efficiency and result accuracy, with proposed ratios and content of modifiers improving the stability and resistance of the rejuvenated asphalt. The regenerated properties of reclaimed asphalt samples are also analyzed.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Green & Sustainable Science & Technology
Yining Zhang, Wenkai Zhu, Xiaolong Chu, Haidong Dong, Dong Liu, Yanyan Liu, Hengjin Chen, Huailei Cheng, Lijun Sun
Summary: This research investigated the impact of design parameters on the performance of recycled hot-mix asphalt (HMA) containing fine reclaimed asphalt pavement (RAP) particles. It was found that adjusting the preheating temperature, compaction effort, asphalt content, and blending duration can improve the rheological performance of the recycled HMA. Additionally, incorporating fine RAP particles in the design can reduce energy consumption and CO2 emissions.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Construction & Building Technology
Martins Zaumanis, Dominique Loetscher, Samuel Mazor, Fabian Stoeckli, Lily Poulikakos
Summary: Experimental study shows that at high milling depth, increasing milling machine moving speed generates larger RAP chunks, leading to more filler content. Additionally, high temperature of milling picks does not age binder, and aggregate angularity is not correlated with milling parameters.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Review
Environmental Sciences
Christiana Adebola Odubela, Haryati Yaacob, Muhammad Naqiuddin Bin Mohd Warid, Khairil Juhanni Binti Abd Karim, Wyom Paul Zakka
Summary: This study analyzed the current knowledge and trends in using rejuvenators in reclaimed asphalt pavement (RAP) using systematic analysis and visualization tools. The study identified core research domains and key clusters based on keywords, as well as top authors, influential journals, institutions, and countries in this research area. This study provides valuable information for policymakers and researchers interested in further research on RAP.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Construction & Building Technology
Ning Li, Wei Tang, Xin Yu, He Zhan, Xin Wang, Zhongyuan Wang
Summary: This study investigates the mobilization stage of reclaimed asphalt pavement (RAP) binder and the diffusion stage of virgin binder in the blending process between RAP and virgin binder. A blending chart relating RAP binder content to carboxyl index (CI) of blended binder was established using Fourier transform infrared spectrometer (FTIR). The diffusion of virgin binder was studied using the tracing method. The results showed that the proposed indicators can comprehensively evaluate the blending efficiency between RAP binder and virgin binder.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Zhaoxing Xie, Hashim Rizvi, Caitlin Purdy, Ayman Ali, Yusuf Mehta
CONSTRUCTION AND BUILDING MATERIALS
(2019)
Article
Engineering, Civil
Ahmad Alfalah, Daniel Offenbacker, Ayman Ali, Christopher Decarlo, Wade Lein, Yusuf Mehta, Mohamed Elshaer
TRANSPORTATION RESEARCH RECORD
(2020)
Article
Engineering, Civil
Mohamed Elshaer, Christopher DeCarlo, Wade Lein, Harshdutta Pandya, Ayman Ali, Yusuf Mehta
TRANSPORTATION RESEARCH RECORD
(2020)
Article
Environmental Studies
Qiang Yang, Huiming Yin, Xin He, Fangliang Chen, Ayman Ali, Yusuf Mehta, Beizhan Yan
TRANSPORTATION RESEARCH PART D-TRANSPORT AND ENVIRONMENT
(2020)
Article
Construction & Building Technology
Zhaoxing Xie, Ayman Ali, Yusuf Mehta, Ahmed Saidi, Sai Venkata Gnaneswari Chitikela, Neirouz Bouhrira, Zhuang Zhuo, Wade Lein, Christopher DeCarlo
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
(2020)
Article
Engineering, Civil
Mahmoud Samara, Daniel Offenbacker, Yusuf Mehta, Ayman Ali, Mohamed Elshaer, Christopher Decarlo
Summary: This study evaluated the impact of rejuvenator type and dose on the laboratory performance of asphalt binders. Results showed that the use of rejuvenators can improve the performance grade and cracking resistance of extracted RAP binders.
TRANSPORTATION RESEARCH RECORD
(2022)
Article
Engineering, Civil
Ashith Marath, Ahmed Saidi, Ayman Ali, Yusuf Mehta, Mohamed Elshaer, Christopher Decarlo
Summary: This study evaluated the electrical conductivity and mechanical performance of electrically conductive asphalt (ECA) mixtures for deicing applications in cold regions. The ECA mixtures were prepared with graphite and carbon fibers as conductive additives, and different lengths of carbon fibers and nominal maximum aggregate sizes were used. Electrical resistivity, rutting susceptibility, cracking resistance, and durability of the ECA mixtures were assessed through various tests. The results showed that aggregates with a nominal maximum aggregate size of 4.75 mm and carbon fibers with a length of 6 mm had the greatest improvement in mechanical performance.
TRANSPORTATION RESEARCH RECORD
(2023)
Article
Engineering, Civil
Ahmad Alfalah, Daniel Offenbacker, Yusuf Mehta, Ayman Ali, Ben C. Cox, Mohamed Elshaer
Summary: This study evaluated the effect of laboratory oxidation and testing temperature on asphalt mixtures' moisture damage. The modified AASHTO T283 testing procedure was introduced to improve the sensitivity to moisture damage in asphalt mixtures. The results showed that higher oxidation and CIT had the greatest impact on TSR%, and asphalt mixtures were more susceptible to moisture damage at STOC and LTOC than OTC. The findings emphasize the need for alternative oxidation conditioning and testing at the CIT to accurately detect moisture damage in asphalt mixtures.
TRANSPORTATION RESEARCH RECORD
(2023)
Article
Engineering, Civil
Ahmed Saidi, Caitlin Purdy, Ayman Ali, Yusuf Mehta, Mohamed Elshaer, Christopher Decarlo
Summary: The study aimed to evaluate the rheological and mechanical properties of emulsion-cement paste (ECP) in cold recycled mixtures. Forty-five combinations of ECP specimens with varying emulsion, cement, and water content were prepared and tested using various methods. The results showed that the proportions of emulsion, cement, and water significantly affected the properties of ECPs, with higher cement and water contents improving high-temperature performance but reducing resistance to intermediate- and low-temperature cracking, while increasing emulsion content improved resistance to fatigue and low-temperature cracking but increased rutting susceptibility at high temperatures. This study provides valuable knowledge for designers of asphalt mixtures involving ECPs.
TRANSPORTATION RESEARCH RECORD
(2023)
Article
Engineering, Civil
Mahdi Habibpour, Ayman Ali, Daniel Offenbacker, Yusuf Mehta, Mohamed Elshaer, Christopher Decarlo
Summary: This study evaluates the potential of using geosynthetics to reinforce flexible pavements and reduce reflective cracking. Three full-scale test strips were constructed, each consisting of different geosynthetic interlayers. Results show that the geogrid-reinforced section had better strain response, while the geotextile-reinforced section exhibited slightly higher bonding. The geosynthetic interlayers mitigated reflective cracking and improved fatigue performance.
TRANSPORTATION RESEARCH RECORD
(2023)
Article
Construction & Building Technology
Venkatsushanth Revelli, Sk Faisal Kabir, Ayman Ali, Yusuf Mehta, Ben C. Cox, Mohamed Elshaer
Summary: This study investigated the compatibility of waste plastic with styrene-butadiene styrene (SBS) in asphalt binders. The presence of waste plastic was found to negatively influence the recovery and cracking performance of asphalt binders at low temperatures. Pre-treating the waste plastic with waste cooking oil enhanced its dispersion and reaction with the binder.
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
(2023)
Article
Construction & Building Technology
Ahmad Alfalah, Ayman Ali, Yusuf Mehta
Summary: This study aimed to establish correlations with reliable and practical tests to estimate the susceptibility of asphalt mixtures to moisture damage. The results showed that Surface Free Energy (SFE) and Fourier Transform Infrared Attenuated Total Reflectance (FTIR-ATR) measurements showed potential in predicting Tensile Strength Ratio (TSR%), and accurate predictions were achieved under long-term aging conditions.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Proceedings Paper
Engineering, Civil
M. Elshaer, M. Oshone, E. Dave, J. E. Sias, Y. Mehta, A. Ali
AIRFIELD AND HIGHWAY PAVEMENTS 2019: DESIGN, CONSTRUCTION, CONDITION EVALUATION, AND MANAGEMENT OF PAVEMENTS
(2019)
Proceedings Paper
Engineering, Civil
H. Pandya, T. Weideli, M. Elshaer, Y. Mehta, A. Ali
AIRFIELD AND HIGHWAY PAVEMENTS 2019: DESIGN, CONSTRUCTION, CONDITION EVALUATION, AND MANAGEMENT OF PAVEMENTS
(2019)
Article
Construction & Building Technology
Qi Jiang, Wei Liu, Shaopeng Wu, Xuanwen Gou
Summary: This study analyzes the erosion mechanisms of NaCl solution on asphalt concrete and finds that NaCl solution softens asphalt and promotes the intrusion of crystalline salt into it. Salt crystallization alters the surface roughness of aggregates, resulting in a decrease in skid resistance but an improvement in compressive strength. Additionally, the concentration of NaCl solution initially has no significant impact on the mechanical performance of asphalt concrete, but its domination gradually increases with the intensification of cyclic effects.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Lili Kan, Lan-qing Dai, Ning Kong, Bin Peng, Fei Wang
Summary: This paper investigates the effect of freezing and thawing cycles on the tensile behavior of cracked ultra-high performance concrete (UHPC). The results show that long-term freezing and thawing action deteriorates the cracking strength, tensile strength, tensile strain, and strain energy of cracked UHPC. On the other hand, the action of water generally favors the development of tensile properties of UHPC. The crack distribution tends to be unsaturated under freezing and thawing environment, and the re-hydration reaction is hindered. The pore structure near the crack varies under different environments.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Xin Xiao, Jingwei Li, Qingke Meng, Xiangshan Hou, Yanhui Liu, Xujiang Wang, Wenlong Wang, Shengtao Lu, Yuzhong Li, Yanpeng Mao, Tong Li
Summary: Preparing gypsum-based self-leveling mortar (GSLM) using beta-hemihydrate gypsum and solid wastes-derived sulfoaluminate cement (WSAC) can improve the mechanical performance of the mortar, but phosphorus impurities can weaken the hydration speed and degree.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Sihang Bao, Junzhen Di, Yanrong Dong, Ziqing Gao, Qing Gu, Yuanfang Zhao, Hongyu Zhai
Summary: Tailings dam break and leakage accidents pose a threat to the safety of people in mining areas and cause severe environmental pollution. This study focuses on solidifying tailing sand using microbial induced calcite precipitation (MICP) to improve strength and fix heavy metals. The curing time of MICP bio-cemented tailings is found to significantly impact the strength of tailings, while its effect on heavy metal fixation is minimal. The optimized MICP curing time is 10 days, resulting in improved strength and cementation of tailings particles.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Ferhat Benmahiddine, Fares Bennai, Achraf Charaka, Ameur El Amine Hamami, Abdelkader Tahakourt, Rafik Belarbi
Summary: This paper studied the effects of hysteresis on the hygrothermal behavior at the building scale. Through laboratory validation and numerical simulations, it was found that hysteresis has a significant impact on the relative humidity and total heat fluxes in buildings, while it does not have a noticeable effect on temperature variations.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
You Gao, Wei He, Xiayang Zhang, De'an Sun, Pei Li
Summary: This study determined the boundary line between the swelling and compression deformation zone in lateritic clay through wetting tests, and proposed a simple bimodal SWRC model. It also found that the existing strength model underestimated the tested values in the medium to high suction range, therefore a segmented strength equation was introduced for enhanced predictions of the strength properties of lateritic clay.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Prabhath Ranjan Kumar Soda, Asheer Mogal, Kalyan Chakravarthy, Nikhil Thota, Nimish Bandaru, Sanjay Kumar Shukla, K. M. Mini
Summary: This study investigates the use of encapsulated bacteria to improve the self-healing ability of concrete. Through various tests, it is found that using 20% cement-coated alginate beads (CCAB) and 5% nanosilica (NS) can achieve optimal strength and healing. This research is significant for enhancing the durability of concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Shizhe Wang, Haiping Wu, Wen Yang, Wei Wang, Zhibo Zhu, Kun Nie, Luoxin Wang, Hua Wang, Jing Wu
Summary: In this study, photothermal-heat storage concrete (PHSC) was developed with excellent photothermal conversion performance and heat storage capacity. By absorbing and storing solar energy during the day and releasing it at night, PHSC can effectively reduce energy consumption in buildings.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Robin Deb, Jialuo He, Geetika Mishra, Yaghoob (Amir) Farnam
Summary: Incorporation techniques of phase change materials in cementitious composites have a significant influence on thermal properties. This study investigated the thermal behavior of low-temperature PCM when subjected to varying temperature change rates and pore confinement inside the porous network of lightweight aggregates. The results showed that ramp rates affect the nucleation and crystallization growth process during the phase transition, and the pore structure of the aggregates affects the supercooling phenomenon and confinement pressure of the PCM.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Eduardo Ferreira, Payam Sotoudeh, Dagmar Svecova
Summary: This study investigates the fatigue behavior of concrete under different stress reversal conditions. The results indicate that stress reversal generally causes more severe damage and reduces the cycles to failure compared to tensile fatigue. Additionally, adding some level of compression contributes to the energy required for failure under stress reversal fatigue. Specimens with higher concentration of fractured aggregates achieve longer fatigue lives.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Mag Raj Gehlot, Sandeep Shrivastava
Summary: This study evaluates the compatibility relationship between plaster bonds and the substrate under an accelerated aging environment, and finds that incorporating an appropriate amount of granite cutting waste can improve the strength parameters and adhesion of the cement mortar.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Min Zhang, Qirui Luo, Mingke Deng, Shixing Zhao
Summary: This study investigated the bond behavior between carbon FRCM composites with added short fibers and concrete substrates. The effects of different factors were considered and 36 specimens were tested and discussed. The experimental results were analyzed in terms of failure mode, load-slip curve, and characteristic parameters, and the contribution of weft yarns was taken into account in the developed bondslip model.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Dengkai Liu, Hongniao Chen, Ray Kai Leung Su
Summary: The susceptibility of building stones to fire and high temperature was investigated in this study by examining their physical and mechanical properties. The results show that both compressive and tensile properties of stones are affected by temperature changes. The tensile strength is particularly sensitive to temperature changes, requiring special attention to the components subjected to tensile stress in stone buildings. Principal component analysis was used to predict the mechanical properties of stones, providing a new method for calculating the residual mechanical properties after high temperature or fire.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Joso Maria Raposo, Eduardo Cavaco, Luis Costa Neves, Eduardo Julio
Summary: This paper investigates the correlation between the friction coefficient and the surface roughness of concrete-to-concrete interfaces. Experimental tests were performed on specimens with different surface treatments, and the surface roughness parameters were analyzed and correlated with the shear strength and friction coefficient. The results showed that certain roughness parameters had a strong positive correlation with the friction coefficient, while others had little or no correlation. A novel combined roughness parameter with optimized correlation was proposed.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Chiara Riccardi, Massimo Losa
Summary: The interest in using bio materials in asphalt pavements is growing due to economic reasons and environmental benefits. This study aimed to review the use of bio extenders as additives in binders, with a focus on replacements greater than 20% of fossil binder. The properties of bio-extended binders were found to vary substantially depending on the biomass source and production process.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
