Moisture damage of asphalt pavement has always been one of the major concerns for researchers in the pavement engineering field. Mitigating this moisture-induced damage is essential for improving pavement performance, extending service life, and reducing lifecycle costs. Several studies have reported that waste plastic can potentially increase the cohesion between asphalt and plastic molecules and enhance the adhesion between asphalt and aggregate, improving the moisture damage resistance of asphalt pavements. The present study aims to understand the effect of incorporating different waste plastics as modifiers on a binder’s fundamental properties, such as cohesive bond energies. To achieve this goal, three different waste plastics—high-density polyethylene (HDPE), polypropylene (PP), and polyethylene terephthalate (PET) in 2%, 4%, 6%, and 8% by weight of the total binder—were used to modify the conventional asphalt binder (PG 58-28). The surface free energy (SFE) was determined by depositing one polar and one non-polar liquid on the solid samples by using the liquid needle drop deposition technique while adopting three different theories. Finally, the cohesive bond energies of the modified asphalt binders were calculated. The results showed that waste plastics significantly increased the total SFE and cohesive bond energy of the asphalt binder up to 4% plastic addition and then dropped. Besides, the comparative analysis revealed that PP modification was most effective for improving moisture damage resistance among the three plastics. Therefore, the use of plastic waste for asphalt binder modification was found to be a promising approach for enhancing moisture damage resistance.

Authors: Biswas M, Paul S,��Hossain K, Waghmare P,��Ahmed A.

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This study evaluated the relative effect of different modifiers and antistripping additives on the rheological properties of asphalt binder PG 58-28, commonly used in Newfoundland and Labrador, Canada. Four antistripping additives: ZycoTherm SP2, Kling Beta 2914, Pave Bond Lite, and AD-Here were used at different dosage rates for laboratory investigations. These antistripping additives were blended into a styrene-butadiene-styrene (SBS) polymer and Gilsonite-modified binder. Later, all binders were aged using rolling thin film oven (RTFO) method. The rutting and cracking parameters, such as the Superpave rutting parameter, Shenoy’s rutting parameter, nonrecoverable creep compliance, crossover frequency, rheological index, and Glover–Rowe parameter were evaluated for SBS- and Gilsonite-modified binders. Comparative rutting parameters analysis showed that both SBS- and Gilsonite-modified binders enhance the rutting performance of the asphalt binder. Additionally, the moisture damage test from the surface free energy test and cracking test revealed that the antistripping agent with SBS-modified binder performed better than the Gilsonite-modified binder.

Authors: Islam T, Hossain K, Khan S, Aurilio M, .

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Structural evaluation of road networks has always been a challenge for road agencies, especially in developing countries like Iran, from both economic and operational perspectives. Many researchers have sought innovative solutions such as developing structural indices or predictive models to address this issue. However, the proposed approaches either rely on costly equipment or have low accuracy. In this study two approaches were employed to address this issue: a weighted summation technique to develop the Pavement Structural Condition Index (PSCI), and a Random Forest Classification (RFC) model. Both methods utilized surface distresses, such as International Roughness Index (IRI), rut depth, and alligator cracking acquired by Laser Crack Measurement System (LCMS) to assess the structural condition. Additionally, a threshold value of PSCI was identified that performs as a crucial discriminator between poor and sound pavement structural status, based on the required structural overlay thickness and using the Receiver Operating Characteristics (ROC) curve analysis. Ultimately, the efficacy of PSCI and RFC models in predicting the structural adequacy of pavement sections was validated with an independent dataset. Consequently, the PSCI model demonstrated an accuracy of 0.842 and a precision of 0.964, while the RFC model achieved superior performance with an accuracy of 0.984 and a precision of 0.976. While the RFC model outperformed the PSCI in identifying structural deficiencies, the PSCI framework provides a practical, cost-effective alternative for network-level pavement condition monitoring, particularly in scenarios where implementing machine learning models is not feasible.

Authors: Barzegaran J, Karimi S M, , Swarna S T, Hossain K.

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Roadway infrastructure is a major transportation facility required for the deployment of autonomous vehicles. However, in the field of vehicle automation research, two critical questions are still unsolved: “Is the current roadway infrastructure sufficient for such highly autonomous vehicles?” and “How can the current roadway infrastructure be assessed to understand whether it is sufficient for such high-level autonomous vehicles or not?” A survey was conducted to answer these questions and to determine essential roadway infrastructure for the safe and successful deployment of highly autonomous vehicles. This study identified that GPS (Global Positioning System) positioning and accuracy, real-time incident updates, detailed mapping, secure data sharing, and connectivity with infrastructure (V2X) are highly important digital roadway infrastructure for automated driving systems. Moreover, experts prioritize vulnerable road user facilities, winter road maintenance strategy, road markings, and roadway visibility among physical roadway infrastructure as highly important. This study might be useful for various stakeholders involved in autonomous vehicle deployment by focusing on roadway infrastructure issues that require attention.

Authors: Zawad M F S,��Hossain K, Barzegaran J, .

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Presently, there is strong consensus that significant temperature and weather changes are fast approaching as a result of climate change. Pavements will be significantly affected by increased temperatures, precipitation, and flooding, and will require present design methodology to be modified accordingly. Several climate change adaptation strategies are easily available to agencies including upgraded����grades, increased Hot Mix Asphalt (HMA) thickness, modified mix gradations, and stabilized base. The objective of this study is to investigate����(LCA) and����(LCCA) for climate change adaptation strategies across various locations in Canada, from a����(GWP) perspective. All analysis was completed leveraging the Athena Pavement LCA software and the LTPP database. The investigated scenarios were (i) a baseline����with no climate change, (ii) a baseline����with climate change, and (iii) an asphalt pavement adapted to withstand climate change, appropriate to the level of changes experienced by the specific location. The study revealed that although there are initial increases in both cost and emission to administer these adaptation strategies, they are offset over the life of the pavements. Increasing the HMA thickness and using stabilized bases were the most expensive and the highest emitting among the investigated strategies, but they are only necessary for extreme coastal climate change regions including British Columbia and Newfoundland. British Columbia is expected to observe a near 30% increase in agency costs to effectively adapt their pavements to climate change. However, these initiatives were found to decrease the overall global warming potential by nearly 10% in comparison to not adapting. The other examined locations, although not returning as drastic of changes, followed similar trends. The conclusions find that climate change adaptation strategies are highly beneficial from the standpoint of both an LCA and LCCA for all of the investigated locations.

Authors: Swarna S T, Hossain K, Bernier A.

Link(s) for the Paper: | ResearchGate

The scarcity of natural aggregate required for infrastructural development (including road construction) is a global problem. Therefore, researchers have constantly been exploring the possibility of different kinds of non-conventional aggregate for sustainable road construction. In this context, over-burnt brick is one among the most common wastes from the construction industry in India, which can be utilized as non-conventional aggregates in the granular layer of pavement structure with the help of a stabilization technique. Pavement structure containing stabilized/cementitious underlying base/sub-base layer is termed as inverted pavement (asphalt layer supported by a relatively stiffer stabilized layer). Attempts have been made in the past to utilize over-burnt brick as an alternative aggregate in different types of pavement structures. However, whether such over-burnt aggregate can be utilized in the stabilized layer of the inverted pavement structure is still unknown. Therefore, this research aimed to explore the potential application of over-burnt brick with the help of stabilization using a cement-fly ash mixture for the base layer of inverted pavement. Likewise, the mixture of fly ash and cement mixture was investigated for their potential application in the subbase layer of the inverted pavement structure. The optimal quantity of cement in both layers for stabilization was initially determined based on strength and durability criteria. Finally, the inverted pavement was analyzed based on the design of experiment approach using the response surface methodology. The analysis of strength and durability components indicated that cement content equal to 6% for brick-fly ash mixture is suitable for the base layer of the inverted pavement. Likewise, cement content equal to 7% with fly ash was found to be suitable for its application in the sub-base layer. It is expected that this research work will help improve the sustainability quotient associated with an inverted pavement structure.

Authors: Khan��S, Ashish P K, Kannelli V, Hossain K, Nagabhushana M N, Tiwari D.

Link(s) for the Paper: | ResearchGate

Over the past 50 years, climate change has threatened both existing and imminent pavement infrastructure. It is also fore-casted to become more aggressive in the future. Therefore, pavement design procedure needs to be adapted accordingly, accounting for the climate change factors. The current study explores the projected climate change in Newfoundland using various climate change models. In addition, this study aims to quantify the influence of climate change on pavement design in Newfoundland and Labrador Province, Canada. To achieve that, a robust mechanistic-empirical pavement design tool (AASHTOWare ME Pavement Design) was used. A statistically downscaled climate change models were extracted from the coordinated regional downscaling (CORDEX) Experiments to predict the future climate. Then the minimum and maximum daily temperatures for five different locations in Newfoundland were extracted using a python code. However, there is a challenge to convert these daily temperatures into hourly temperatures. Therefore, two relatively new hourly data estimation procedures, such as the modified imposed morphing method (M-IOMM) and Sine (14R-1) were used. These hourly estimated data were utilized to further predict the pavement performance for all the five locations in Newfoundland, Canada. This study concludes that climate change accelerates pavement deterioration compared to baseline climate

Authors: , ,

Link(s) for the Paper: | ResearchGate

Abstract:

Limited field investigations have evaluated the impact of traffic on the snow melting capacity of salts. This paper will describe an extensive field study that includes 1,200 tests that are conducted during 100 snow events over three winter seasons (2012, 2013, and 2014) to quantify the traffic impact on snow melting capacity. The tests will be conducted in an active parking lot, and on parking stalls and driveways, which could increase the applicability of the results to real-world scenarios. The deicing performance of salt will be compared between both areas with different traffic patterns for bare pavement regain time (BPRT). The developed model quantified the reduction in BPRT from 21% for a low traffic volume of 5 vehicles/h to an 86% reduction for a high traffic volume of 50 vehicles/h. The deicing performance models that were calibrated for parking stalls and driveways could be directly used to determine the most cost-effective application rates to treat parking lots and sidewalks based on specific weather, facilities, and traffic conditions.

Authors: Fu L, El-Hakim M.

Link(s) for the Paper: | ResearchGate

Abstract:

There is strong evidence for climate change leading to a rise in temperatures and achange in precipitationtrends. These environmental changes pose a threat to pavement infrastructure worldwide. Therefore, it is necessary to modifypavement designprocedures to consider climate change. In addition, it is necessary to consider suitablepavement materialsfor future climate. The objective of this study is to develop a framework for selecting an appropriate adaptation strategy to mitigateclimate change impact. To fulfill this, the influence of climate change on long-termpavement performancein Canada has been quantified over sixteen Canadian pavement sections located over various provinces in Canada. In addition, the fundamental causes of pavement deterioration due to climate change were determined using ten differentclimate change models. Various adaptation strategies such as upgradingasphalt bindergrade, increasing the thickness of asphaltic concrete layer, increasing the base layer thickness, and using stabilized base layers were analyzed to reduce pavement deterioration and to extend the service life of the pavement. Unlike the other studies, pavement temperatures were determined using Enhanced Integrated Climate Model (EICM) to determine the change in binder grade for the future climate in the adaptation process. The study found that by 2070 all examined locations will require an upgrade in binder grade and the majority will require an upgrade in mixture gradation. Furthermore, the east and west coast will be more vulnerable to climate change and require additional measures in comparison to Central Canada. Newfoundland and Prince Edward Island are the only locations that will need to consider a change in asphalt thickness while British Columbia is the only location eventually requiring a stabilized base. This study emphasizes the necessity of climate change adaptation strategies for Canadian asphalticconcrete pavements.

Authors: , Mehta Y A, Bernier A.

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The inverted pavement system is an alternate type of pavement system compared to rigid and flexible pavement systems. The base layer of inverted pavements is generally a cement-treated layer with varied cement content, depending on the unconfined compressive strength criteria and durability. In the present study, fly ash was used as a replacement for aggregate in the cemented base layer; in the cemented subbase layer, only fly ash and cement were used. An optimized combination of fly ash (22%), aggregate (78%), and cement (3%) was used for the cemented base layer. For the cemented subbase layer, 7% cement and 93% fly ash were used. Therefore, 22% aggregate in cemented base and 100% aggregate in cemented subbase layer can be saved. For the field investigation, a test track was constructed for 0.5��million standard axles (MSA), and performance was monitored with both nondestructive testing (NDT), that is, falling weight deflectometer (FWD), Benkelman beam deflection (BBD), and ultrasonic pulse velocity (UPV), and destructive testing (actual loading, plate load test and dynamic cone penetration test) on the test track. The NDT testing showed that the cemented layers performed well. However, it was found that the pavement failed prematurely under actual loading. The plate load test showed that crack relief failed because of compaction issues. Last, finite-element modeling of the test section using PLAXIS 3D version 2013 showed the vertical stress distribution in the inverted pavement.

Contributors:��, Nagabhushana M N, Tiwari D, Guruvittal U K, Bazan C.

Link(s) for the Paper: |��ResearchGate