Education

Research Description

Dr. Tayebali is interested in pavement materials, pavement design and rehabilitation, performance based mix design and analysis systems for conventional and modified bituminous mixes.

Publications

Quantifying moisture damage in asphalt concrete using axisymmetric flexural vibration technique

Rashetnia, R., Kusam, A., Yadav, S., Pour-Ghaz, M., & Tayebali, A. (2022), INTERNATIONAL JOURNAL OF PAVEMENT ENGINEERING, 23(3), 523–535. https://doi.org/10.1080/10298436.2020.1757671

Evaluating Moisture Damage Using Impact Resonance Test

Yadav, S., Kusam, A., & Tayebali, A. A. (2021), JOURNAL OF TESTING AND EVALUATION, 49(6), 4118–4134. https://doi.org/10.1520/JTE20200372

A mechanistic approach to evaluate the potential of the debonding distress in asphalt pavements

Cho, S.-H., Karshenas, A., Tayebali, A. A., Guddati, M. N., & Kim, Y. R. (2017), INTERNATIONAL JOURNAL OF PAVEMENT ENGINEERING, 18(12), 1098–1110. https://doi.org/10.1080/10298436.2016.1149837

Laboratory Evaluation of Workability and Moisture Susceptibility of Warm-Mix Asphalt Mixtures Containing Recycled Asphalt Pavements

Kusam, A., Malladi, H., Tayebali, A. A., & Khosla, N. P. (2017), JOURNAL OF MATERIALS IN CIVIL ENGINEERING, 29(5). https://doi.org/10.1061/(asce)mt.1943-5533.0001825

Laboratory Evaluation of Warm-Mix Asphalt Mixtures for Moisture and Rutting Susceptibility

Malladi, H., Ayyala, D., Tayebali, A. A., & Khosla, N. P. (2015), JOURNAL OF MATERIALS IN CIVIL ENGINEERING, 27(5). https://doi.org/10.1061/(asce)mt.1943-5533.0001121

Evaluation of warm mix asphalt technology for surface mixtures

Ayyala, D., Malladi, H., Khosla, N. P., & Tayebali, A. A. (2014), Asphalt Pavements, vol 1, 701–708. https://doi.org/10.1201/b17219-88

Importance of Normal Confinement to Shear Bond Failure of Interface in Multi layer Asphalt Pavements

Karshenas, A., Cho, S.-H., Tayebali, A. A., Guddati, M. N., & Kim, Y. R. (2014), TRANSPORTATION RESEARCH RECORD, (2456), 170–177. https://doi.org/10.3141/2456-17

Effects of higher percentage of recycled asphalt pavement on pavement performance

Visintine, B., Khosla, N. P., & Tayebali, A. (2013), ROAD MATERIALS AND PAVEMENT DESIGN, 14(2), 432–437. https://doi.org/10.1080/14680629.2013.779310

Gradation effects on the mechanical response of crushed stone aggregate

Cunningham, C. N., Evans, T. M., & Tayebali, A. A. (2013), INTERNATIONAL JOURNAL OF PAVEMENT ENGINEERING, 14(3), 231–241. https://doi.org/10.1080/10298436.2012.690518

Quantifying the Greenhouse Gas Emission Reductions Associated with Recycling Hot Mix Asphalt

Levis, J. W., Barlaz, M. A., Tayebali, A., & Ranjithan, S. R. (2011), Road Materials and Pavement Design, 12(1), 57–77. https://doi.org/10.1080/14680629.2011.9690352

View all publications via NC State Libraries

Grants

Use of Moisture-Induced Stress Test (MIST) to Determine Moisture Sensitivity of Asphalt Mixtures

NC Department of Transportation(8/01/16 - 7/31/19)

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Use of Moisture-Induced Stress Test (MIST) to Determine Moisture Sensitivity of Asphalt Mixtures

Sponsor: NC Department of Transportation

Start Date: 8/01/16

End Date: 7/31/19

Abstract

Asphalt mixtures used in pavement construction are required to meet the NCDOT moisture sensitivity specifications. The current lab procedure to test moisture sensitivity uses conditioning procedures as per modified AASHTO T283. This is a fairly lengthy procedure involving specimen preparation, sample saturation, conditioning the samples for 24 hours, and then indirect tension testing. The variability involved in TSR test results is also observed to be high. The current test method uses the ratio of indirect tensile strength of the conditioned and unconditioned specimens (TSR). The indirect tensile strength is a qualitative measure of the moisture sensitivity. There is a need for a quicker test method(s) that is quantitative and has less variability. The new test should also lend itself to measure intrinsic properties such as the dynamic modulus of asphalt concrete that will allow inferior mixtures to be eliminated even though they may pass the TSR test.

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Effectiveness of TSR Test in Evaluating Moisture Sensitivity of WMA Mixes

NC Department of Transportation(8/16/13 - 6/30/16)

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Effectiveness of TSR Test in Evaluating Moisture Sensitivity of WMA Mixes

Sponsor: NC Department of Transportation

Start Date: 8/16/13

End Date: 6/30/16

Abstract

The NCDOT requires that asphalt mixtures used in pavement construction meet the NCDOT moisture sensitivity specifications prior to approval of the job mix formula (JMF). Foaming-based warm mix asphalt (WMA) mixes, based on water injection WMA technologies, such as Astec?s Double Barrel® foamed technology, and WMA technologies that use Zeolite additives such as Advera, tend to fail the current required tensile strength ratio (TSR) tests. However, pavements constructed with these same WMA mixes in the United States and in North Carolina have performed well to date. Either the current TSR test protocol needs to be modified or a new test is needed for WMA mixes. The objectives of the proposed research are: (1) to evaluate whether or not the residual trapped moisture in WMA mixes affects the TSR test results, and investigate whether or not the curing of compacted specimens is required for WMA mixes; (2) to investigate a more realistic moisture conditioning procedure that mimics the effects of moisture on the performance of foaming-based WMA mixes used in in-service pavements; (3) to evaluate the stiffness, fatigue performance, and rutting potential of the foaming-based WMA mixes in a moisture-conditioned state so that the actual degradation of these mixes can be compared directly to the results from TSR and indirect tensile (IDT) strength tests; and (4) to explore modifications to the current TSR test protocol or to develop alternative test methods such as acoustic emission, digital imaging and spectrophotometer analysis that can be used in lieu of TSR tests for foaming-based WMA mixes

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Surface Layer Bond Stresses and Strength

NC Department of Transportation(8/16/12 - 10/15/14)

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Surface Layer Bond Stresses and Strength

Sponsor: NC Department of Transportation

Start Date: 8/16/12

End Date: 10/15/14

Abstract

In North Carolina, the investigations of several highway projects have indicated that the debonding of the top surface layer in an asphalt pavement is a contributing factor in the premature cracking of pavements. Examples of these pavements include I-795 in Wayne County and US-64 in Martin County. In addition, an occurrence of excessive debonding was observed some years ago in Division 13 of the NCDOT. Pavements in Buncombe County, where emulsions were used as a tack coat, experienced more incidents of debonding than pavement sections in Rutherford County where PG 64-22 asphalt cement was used as the tack coat. In these pavements, the debonding distress often was accompanied by cracking. Although it is not clear whether the cracking or the debonding occurred first, the debonding nonetheless contributed to the distress and failure of the pavement.

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Impact of WMA Technology on the Use of RAP Mixtures in NC

NC Department of Transportation(8/16/12 - 5/15/15)

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Impact of WMA Technology on the Use of RAP Mixtures in NC

Sponsor: NC Department of Transportation

Start Date: 8/16/12

End Date: 5/15/15

Abstract

This study proposes to study the effect of using RAP in WMA. Various HMA and WMA mixtures, with and without RAP material, will be characterized with respect to fatigue life, resistance to permanent deformation, susceptibility to thermal cracking, and moisture susceptibility. The fatigue life and rut resistance of the mixtures will be evaluated by conducting dynamic modulus and flow number tests. The moisture-induced damage of the mixtures will be determined using the Tensile Strength Ration (TSR) as per AASHTO T-283 test procedure. Creep compliance obtained from the Indirect Tension Test will be used to characterize susceptibility of the mixtures to low temperature thermal cracking. A database of level 1 input for all the various mixtures will be developed for use in performance analysis using DARWin-ME. The study also proposes to conduct life cycle cost analyses to determine economy involved in using RAP material with WMA in asphalt concrete mixtures. Finally, the optimal type of mixture with the best possible combination of percentage RAP material and WMA technology for NCDOT materials will be reported for use in the construction of new pavements.

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An Evaluation of Warm Mix Asphalt Technologies for NCDOT Mixes

NC Department of Transportation(8/16/10 - 6/30/13)

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An Evaluation of Warm Mix Asphalt Technologies for NCDOT Mixes

Sponsor: NC Department of Transportation

Start Date: 8/16/10

End Date: 6/30/13

Abstract

After success in Europe, Warm-Mixed asphalt (WMA) technology started to spark interest in the United States. The major advantages of implementing WMA technology are its ability to reduce emissions, lower energy consumption and increase workability. Several state DOTs have invested in research in WMA including Virginia, Tennessee, California and Texas. There are several additives being used for the production of Warm-Mixed asphalt. Those proposed to be used in this research are Zeolite and either Evotherm 3G or Sasobit®. In addition to the use of WMA additives, ?The Foamer? device that produces WMA will also be used. Use of these products has shown that there is a consistent reduction in production temperatures of up to 50oF. This temperature reduction has the potential to reduce production costs and emissions from the production plants. Implementation of WMA technology may pose some important engineering challenge. As most of the technologies use water to increase workability, the mixtures may be susceptible to moisture sensitivity. In addition, although, reduction in mix production temperature will subject the mix to less oxidative hardening, the reduced hardening may increase the mix susceptibility to permanent deformation. The objectives of this research project are to evaluate the moisture susceptibility of North Carolina mixes using three different WMA technologies. Volumetric and material performance characteristics will be evaluated using WMA in comparison to HMA. This comparison will enable NCDOT to select the best WMA technology and determine if such technology will result in adequate mix performance with respect to moisture susceptibility, fatigue, and permanent deformation. If the WMA mixes are adequate, it may result in more economical pavements in the present increasing fuel cost environment.

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Effect of Gradation on Predicted Performance of Aggregate Base Course

NC Department of Transportation(1/01/08 - 6/30/09)

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Effect of Gradation on Predicted Performance of Aggregate Base Course

Sponsor: NC Department of Transportation

Start Date: 1/01/08

End Date: 6/30/09

Abstract

The unbound granular layer serves as a major structural component in flexible pavement performance. The gradation acceptance criteria used by the North Carolina Department of Transportation (NCDOT) for aggregate base course (ABC) were adopted based on experience many years ago and have not undergone any significant changes. Because the current specification is not directly related to performance, it is difficult to quantify the effect of ABC material gradation and aggregate type on pavement performance. The primary objectives of this research study are to evaluate the effect of aggregate gradation and type on the mechanical and hydraulic properties of the ABC materials; and to develop numerical model(s) based on the discrete element method (DEM) to predict mechanical and hydraulic properties with changes in gradation and type of aggregate. It is anticipated that this research study will result in performance-related criteria that can be incorporated into the NCDOT Standard specifications that are used for acceptance of ABC material incorporated into the pavement structure. The results of this study will enable NCDOT to numerically extrapolate ABC material properties for changing aggregate gradation and type with limited testing. It will also allow NCDOT to use more realistic ABC material properties in the AASHTO 2002 MEPDG structural design process for pavement structures.

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Effect of Prolonged Heating on the Asphalt-Aggregate Bond Strength of HMA Containing Liquid Antistrip Additives

NC Department of Transportation(7/01/06 - 6/30/08)

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Effect of Prolonged Heating on the Asphalt-Aggregate Bond Strength of HMA Containing Liquid Antistrip Additives

Sponsor: NC Department of Transportation

Start Date: 7/01/06

End Date: 6/30/08

Abstract

The objectives of this research are to determine the effect of prolonged heating on (1) asphalt-aggregate bond strength and (2) the moisture sensitivity of asphalt mixtures. In particular, this study will first evaluate the performance of mixtures using the tensile strength ratio test (AASHTO T283), and second, study the effect of additive content and prolonged heating on the surface interaction between asphalt binder and aggregate.

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Fatigue Characterization of PMI Asphalt Mixtures

Petrochem Marketing, Inc.(9/15/05 - 12/15/05)

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Fatigue Characterization of PMI Asphalt Mixtures

Sponsor: Petrochem Marketing, Inc.

Start Date: 9/15/05

End Date: 12/15/05

Abstract

The objective of this testing program is to characterize the fatigue response of PMI asphalt mixtures using beam fatigue testing device and establish strain versus number of cycles to failure relationship.

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