Yazar "Gedik, Abdulgazi" seçeneğine göre listele

Listeleniyor 1 - 8 / 8
  • Küçük Resim Yok
    Öğe
    A Holistic Approach Weighing Up the Pros and Cons of Winter Road Maintenance Operations: A State-of-Art Review
    (Springer Heidelberg, 2025) Gedik, Abdulgazi
    Heavy snow and freezing rain hit essential parts of highway networks in winter time, bringing mobility to a halt, and causing chaos and major disruptions to the road transport. Understanding the role that deicing practices and deicers play in winter road maintenance operations underscores the concordant importance of protecting transportation infrastructures and the environment. To this end, this paper aims to provide a thorough review of the existing literature and to gather prominent findings elucidating the impact of each technique and agent commonly employed in snow-fighting. Findings from previous studies revealed that, in most cases, the chloride salts-driven deteriorations provided a particularly stark example of the difficult-to reverse and unpredictable hazards to highway structures, the ecosystem and, in turn, human life. It is therefore vital to select and apply the right type and amount of deicing materials in the right place at the right time. More specifically, past scholarly work suggested that the use of chlorides should be strictly regulated, optimized and diminished by at least 50% to recover the current conjuncture. On the other hand, the adverse effects of other approaches, particularly the contribution of winter service vehicles employed in mechanical snow and ice removal to greenhouse gas emission, air pollution and climate change should not be underestimated. As this critical environmental issue has not been systematically investigated in any other reviews to date, future endeavors should address this research gap regarding the cold-climate regions overburdened by fossil-fuel reliant vehicles in snow and ice clearing. Solving this problem could promote mechanical snow clearing and lead to more extensive applications. Building upon previous literature, the purpose of this paper is to identify further research gaps in snow-fighting and to lay the groundwork for future works. Hence, this study is an attempt to incentivize policymakers and key stakeholders in transportation engineering to discover chloride salt-free deicing sources, eco-friendlier techniques, and sustainable maintenance strategies for winter roads.
  • Küçük Resim Yok
    Öğe
    Assessing the Potential of Olive Stone Powder as a Bitumen Biopolymer Through Physical, Chemical, and Rheological Characterization
    (Mdpi, 2026) Ozcan, Ozgur; Yumrutas, Halil Ibrahim; Gedik, Abdulgazi; Ozcanan, Sedat; Apak, Mustafa Yurdabal
    The present study aims to investigate the feasibility of utilizing olive stone powder (OSP), an agricultural by-product, as a modifier for bituminous binders. OSP was incorporated into a neat bitumen at dosages of 2%, 4%, 6%, and 8% by weight, and the modified binders were subjected to comprehensive laboratory tests along with the unmodified reference binder. The evaluation framework included physical, rheological, and chemical characterization tests. The results of physical tests indicate that, although the addition of OSP led to a slight increase in binder stiffness, it effectively reduced temperature susceptibility while maintaining workability within acceptable limits. Rheological results showed that OSP modification improved rutting resistance at high temperatures, while low-temperature performance was preserved at 2% and 4% OSP contents; however, increased stiffness at higher dosages (6% and 8%) may increase thermal cracking susceptibility. Chemical analyses confirmed that OSP was homogeneously dispersed within the bitumen matrix and improved binder behavior primarily through physical interactions, while also enhancing thermal stability. Overall, the results indicate that OSP behaves as a biopolymer-based, filler-like modifier and provides performance improvements primarily through physical structuring. With these characteristics, OSP offers an environmentally friendly and economical solution for bituminous binders and represents a promising option for sustainable pavement materials.
  • Küçük Resim Yok
    Öğe
    Effects of NiO nanomaterial as a bitumen modifier on asphalt mixtures' performance against fatigue and low-temperature cracking in the presence of de-icer agents
    (Elsevier, 2026) Hamedi, Gholam Hossein; Gedik, Abdulgazi
    Chloride-based de-icing salts are effective for winter road safety but raise environmental and economic concerns by accelerating asphalt deterioration through runoff, penetration, and chemical erosion. To counteract damage driven by deicer, this study examined nano-nickel oxide (nano-NiO) at 2 % and 4 % by weight as a PG 58-22 and PG 64-16 bitumen additive under moisture exposure caused by three common brine solutions: sodium chloride (NaCl), magnesium chloride (MgCl2), and calcium chloride (CaCl2). The experimental program employed semicircular bending (SCB) tests at low temperatures (-10 and -20 degrees C), Pull-off tests at intermediate and low temperatures (-20, -10, 15, and 25 degrees C), and indirect tensile fatigue (ITF) tests at intermediate temperatures (15 and 25 degrees C). The results demonstrated that moisture conditions induced by de-icing agents significantly worsen the cohesion strength, adhesion resistance, fracture properties, and shorten the fatigue life of asphalt mixtures, with CaCl2 showing the most detrimental effects. In contrast, incorporating 2 % and 4 % nano-NiO substantially improved these parameters; thus, the nanomaterial enhanced mixture integrity by reinforcing cohesion and adhesion bonds, thereby preventing crack formation and stress concentration. Mixtures modified with nano-NiO demonstrated greater resistance to failure at low temperatures. This was evidenced by an increase in the energy required to create a crack (fracture energy) and an increase in the critical stress intensity at the crack tip required for brittle fracture (fracture toughness). Furthermore, the modified samples showed an increased fatigue life (number of load cycles until final failure). Consequently, modified mixtures exhibited superior fatigue and fracture resistance when exposed to de-icing salts. Based on the statistical analysis, it was determined that bitumen modified with 4 % nano-NiO exhibited the best performance in enhancing bitumen-aggregate adhesion/cohesion at low and intermediate temperatures, improving the mixture's lowtemperature fracture properties, and extending its intermediate-temperature fatigue life. Furthermore, the evaluation of the low- and intermediate-temperature performance of the base combinations tested in this study revealed that PG 64-16 bitumen, when used with limestone aggregate, produces a mixture with higher stability against the damaging conditions induced by de-icing chemicals. In summary, the results indicate that HMAs made with PG 64-16 bitumen modified with 4 % nano-NiO and limestone aggregate possess the greatest resistance to fatigue and thermal cracking in corrosive de-icing salt environments.
  • Küçük Resim Yok
    Öğe
    Novel approaches and materials for healing asphalt cracks
    (Croatian Soc Civil Engineers-Hsgi, 2023) Gedik, Abdulgazi; Ozcan, Ozgur; Ozcanan, Sedat
    Premature cracks in an asphalt pavement may damage its intact structure, substantially decrease its load-bearing capacity, degrade its driving comfort and safety, and even lead to total pavement failure. This paper provides a detailed state-of-the-art review regarding the impact of new approaches and materials on the curing of asphalt cracking, along with an explanation of their advantages, deficiencies, improvement opportunities, and future perspectives. By providing this background information, this study intends to contribute to the discovery of ground-breaking technical solutions and cost-effective materials to remedy premature asphalt pavement cracks at the right place and time. Future studies are recommended to advance efforts to discover more effective, practical, cost-saving, sustainable, and eco-friendly methods and agents for healing asphalt cracks.
  • Küçük Resim Yok
    Öğe
    Recycling COVID-19 health care wastes in bitumen modification: a case of disposable medical gloves
    (Springer Heidelberg, 2023) Gedik, Abdulgazi; Ozcan, Ozgur; Ozcanan, Sedat
    Disposable medical gloves (DMGs) have long been used to mitigate the risk of direct exposure to diverse microorganisms and body fluids; hence, they are a critical weapon to protect patients and healthcare staff from infectious diseases. Measures to control the spread of COVID-19 have sparked the production of an excessive number of DMGs, most of which are eventually being disposed of in landfills. Untreated DMGs in landfills do not only pose a direct risk of transmitting coronavirus and other pathological germs but also pollute air, water, and soil dramatically. As a healthier alternative, recycling discarded polymer-rich DMGs into bitumen modification is considered to be a prospective waste management strategy applicable to the asphalt pavement industry. In this study, this conjecture is tested by examining two common DMGs - latex gloves and vinyl gloves - at four different percentages (1%, 2%, 3%, and 4% by weight). The morphological characteristics of DMG-modified specimens were inspected by using a high-definition scanning electron microscope (SEM) equipped with an energy dispersive X-ray analyzer (EDX). A wide range of laboratory tests including penetration, softening point temperature, ductility, and elastic recovery were undertaken to evaluate the impact of waste gloves on the conventional engineering properties of bitumen. Moreover, viscoelastic behavior and modification processing were studied by conducting the dynamic shear rheometer (DSR) test and the Fourier transform infrared spectroscopy (FTIR) analysis. Test results have revealed the outstanding potential of recycled DMG waste for modifying neat asphalt binder. More specifically, bitumens modified with 4% latex glove and 3% vinyl glove were seen as capable of superiorly withstanding permanent deformations caused by heavy axle loads at high service temperatures. Furthermore, it has been shown that 1.2 tons of modified binder would embed approximately 4000 pairs of recycled DMGs. This study shows that DMG waste can be used as a viable modifier, which would help open a new avenue for mitigating the environmental pollution arising from the COVID-19 pandemic.
  • Küçük Resim Yok
    Öğe
    Repurposing recycled walnut shell as an anti-aging agent into asphalt binder: A multi aspect evaluation
    (Elsevier Sci Ltd, 2025) Gedik, Abdulgazi
    Bitumen aging undermines road surface conditions by decreasing resistance to deformation and cracking, both of which eventually shorten the service life of asphalt pavements. Accordingly, the pavement scientific community has been exploring alternate research efforts through investigations of a wide range of biowastes that could serve as cost-saving, environmentally sustainable, and long-term effective anti-aging agents. In line with these efforts, the present study has been dedicated to scrutinizing the effects of incorporating recycled walnut shell as an antioxidant for asphalt binder. To this end, walnut shell powder (WSP) was first added to a straight 50/70 penetration bitumen at various concentrations (2 %, 4 %, 6 %, and 8 % by weight) by means of an ultra-high shear mixer. Next, the bio-binders and base bitumen were exposed to short- and long-term aging. The changes in physical, rheological, and chemical properties were analyzed as a means of comparing and contrasting the aging degree of WSP samples with that of the control binder. Consistency test results showed that adding WSP alleviated the hardening effect of the aging process. In contrast to the plain binder, WSP binders had better antiaging performance as proven by the lower change in viscoelastic behavior, the decline in the formation of oxygenated products, and the improved resistance to thermal degradation. Decreasing the aging-related hardening and embrittlement, WSP significantly enhanced the bitumen's fatigue resistance and low-temperature performance. Overall, this study provides insights into the extent to which the inclusion of WSP serves to reduce thermal-oxidative bitumen aging. Specifically, 8 %WSP was found to have the best age-retardation effect as evidenced by its lowest aging indices. Given WSP's lignocellulosic composition and natural anti-oxidant properties, this study offers a new solution for improving the anti-aging performance of bitumen.
  • Küçük Resim Yok
    Öğe
    Restorative Design of Underground Structures Damaged by Kahramanmaras (Turkey) Earthquakes on 6 February 2023: A Case Study on Erkenek Highway Tunnel
    (Mdpi, 2025) Gedik, Abdulgazi
    On 6 February 2023, two consecutive earthquakes, with magnitudes of 7.8 and 7.7 (Mw), struck Kahramanmaras Province in the Mediterranean region of Turkey. A thorough evaluation of post-seismic damage to underground structures is critically important for ensuring both structural safety and operational serviceability. Focusing on the Erkenek Tunnel, this study provides a systematic investigation to assess the impact of the devastating Kahramanmaras earthquakes on highway tunnels. The tunnel sustained significant damage, primarily concentrated in its inner lining structures, and as a result, its left tube was shut down for service. Based on the in situ observations, geological conditions, initial design documents and construction techniques, a numerical analysis was conducted to model critical tunnel sections and evaluate their structural stability. Considering both static loads and seismic forces, restoration design works, techniques and construction sequences are recommended for the damaged sections of the Erkenek Tunnel. As the earthquake damage sustained by underground structures is a rare case, the methodology and findings of this study regarding post-seismic tunnel inspections and rehabilitation designs shed light on the maintenance works of in-service tunnels in earthquake-prone zones.
  • Küçük Resim Yok
    Öğe
    Utilising cellulose fibre in stone mastic asphalt
    (Croatian Association of Civil Engineers, 2023) Gedik, Abdulgazi
    In this study, the optimum amount of cellulose fibre (CF) use was evaluated to better understand its influence on the volumetric design parameters of stone mastic asphalt (SMA) with polymer-modified bitumen (PMB). SMA-PMB specimens were manufactured, and their primary volumetric properties were compared with those of the respective SMA-PMB mixtures without CF. The results revealed that the addition of CF as a stabilising agent increased the optimal binder content, voids in the mineral aggregate, and voids filled with binder but decreased air voids and bulk specific gravity. The results suggest that the utilisation of CF, along with an increased optimum binder content, slightly increased the primary manufacturing cost of SMAs. © 2023, Croatian Association of Civil Engineers. All rights reserved.