Assistant Lecturer

Apr 27, 2006 - Present

Effects of maltene on the attributes of reclaimed asphalt pavement: Performance optimisation

Oct 4, 2021

Journal Construction and Building Materials

publisher Elsevier

DOI https://doi.org/10.1016/j.conbuildmat.2021.124210

Volume 302

The asphalt mixtures using elevated percentages of the reclaimed asphalt pavement (RAP) are of significant interest due to its ability to address environmental issues and reduce cost of asphalt. However, utilising elevated RAP content is associated with several disadvantages. Hence, this study explores the potential application of maltene as a rejuvenator to improve the output of asphalt mixtures incorporating RAP binder. The contents of maltene were optimised according to several parameters, namely penetration, softening point, ductility, and viscosity tests. Thereafter, the specimens containing an optimum maltene percentage were assessed using maltene-to-asphaltene ratio, storage stability, Dynamic Shear Rheometer (DSR), Bending Beam Rheometer (BBR), Fourier Transform Infrared (FTIR) spectroscopy and Thermogravimetric Analysis (TGA) measurements. Subsequently, the mechanical characteristics of asphalt mixtures were analysed using Marshall Stability, moisture damage, resilient modulus (MR), and Cantabro loss tests. The results demonstrated that 8% and 16% of maltene restored the physical properties of 30% and 50% of RAP binder, respectively. In addition, the workability was improved due to the reduction of viscosity, while maltene-rejuvenator managed to compensate the light components of RAP binder that were lost during the lifespan. As a result, the high- and low-temperature performance of RAP binder were restored approximately to that of virgin asphalt (VA). The oxygenated indices of RAP binder were effectively abated by blending with maltene. The TGA exhibited that the thermal stability of rejuvenated asphalts was close to VA. Accordingly, the mechanical characteristics of rejuvenated mixtures were improved compared to the VA mixture. Therefore, the maltene with a suitable dose is recommended to rejuvenate the RAP binder, and reuse it in the pavement construction.

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A new approach to enhance the reclaimed asphalt pavement features: role of maltene as a rejuvenator

Sep 23, 2021

Journal Road Materials and Pavement Design

publisher Elsevier

DOI DOI:10.1080/14680629.2021.1984978

Issue 11

Volume 23

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Assessment of Inhaled Hydrogen Sulfide in Suppressing Deterioration in Patients With COVID-19

Apr 24, 2021

Journal SHOCK

publisher Elsevier

DOI DOI: 10.1097/SHK.0000000000001722

Issue 4

Volume 63

Novel coronavirus disease 2019 (COVID-19) is an emerging disease of public health concern, and the current pandemic is having a major global impact. While there is no specific recommended treatment for COVID-19, hydrogen sulfide has the potential to be of therapeutic value for managing acute respiratory illness in patients with COVID-19. However, inhaled hydrogen sulfide has not yet been formally evaluated. Given the extent of the COVID-19 pandemic and the large numbers of hospitalized patients requiring respiratory support, clinical use of inhaled hydrogen sulfide may become an alternate rescue therapy to Suppressing Deterioration in Patients with COVID-19 for the management of acute respiratory distress syndrome (ARDS) in patients with COVID-19. Increasing attention is being focused on the development of therapeutic strategies against this disease. We read, with great interest, the article by Renieris et al. (1) “Serum hydrogen sulfide and outcome association in pneumonia by the SARS-CoV-2 corona virus” published in this journal. While there is no specific recommended antiviral treatment, and vaccines have yet to be approved, the authors provided a powerful evidence for the connection between hydrogen sulfide concentration in patients serum and outcome survivors of patients from SARS-CoV-2 illness; therefore, hydrogen sulfide (H2S) inhalation therapy may be included in the strategy as a promising therapeutic candidate.

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A review on rejuvenating materials used with reclaimed hot mix asphalt

Apr 3, 2021

Journal Canadian Journal of Civil Engineering

publisher Canadian Science Publishing

DOI https://doi.org/10.1139/cjce-2019-0635

Volume 48

In recent years, flexible pavement construction technology has relied heavily on the use of reclaimed asphalt pavement (RAP). However, the brittle nature of RAP, which stems from the use of an aged asphalt, has introduced numerous complexities into the process, with important implications to pavement service life. The properties of the aged asphalt can be rejuvenated to improve the performance and the behavior of RAP mixtures. This paper presents a review of past works that have used rejuvenating materials with RAP, including their benefits and drawbacks, as well as the optimal approach to increase RAP content in asphaltic mixtures. The method of rejuvenating aged asphalt and the mechanism of rejuvenation are also reviewed. The findings of this review can be used to predict the current and future challenges in the regeneration of RAP mixtures using rejuvenating materials.

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Evaluating the Chemical and Rheological Attributes of Aged Asphalt: Synergistic Effects of Maltene and Waste Engine Oil Rejuvenators

Aug 9, 2020

Journal Arabian Journal for Science and Engineering

publisher springer nature

Volume 45

The service life of road pavement reduces as it ages and loses its properties due to the exposure to varying traffic loads and climatic conditions. This study explores the potential rejuvenation of the aged asphalt properties to enable it to be reused in pavement by adding hybrid rejuvenator (WEO-MLT). The WEO-MLT is composed of waste engine oil and maltene (MLT). Four types of binders, namely virgin asphalt, aged asphalt, 40% aged asphalt and rejuvenated asphalt, were prepared and evaluated via rheological and chemical tests [e.g. storage stability, asphaltene-to-MLT ratio, dynamic shear rheometer, bending beam rheometer, Fourier transform infrared (FTIR), thermogravimetric analysis and stripping resistance tests]. The results revealed that the WEO-MLT markedly enhanced the properties of aged asphalt at low and high temperatures. In contrast, the outcomes of FTIR suggested that the ageing properties of asphalt were not improved significantly by WEO-MLT due to the presence of a carboxyl group in its composition. TGA indicated that the initial decomposition for rejuvenated asphalt was approximately close to virgin asphalt. The stripping resistance test divulged the comparable performance of the rejuvenated asphalt to that of virgin asphalt. Therefore, WEO-MLT can be potentially used in the rejuvenation of the aged asphalt, paving the way to sustainable and eco-friendly asphalt production.

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