Faculty Publications
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Publications by NITK Faculty
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Item Characterization of porous friction course mixes for different Marshall compaction efforts(2009) Suresha, S.N.; George, V.; Ravi Shankar, A.U.R.Porous friction courses (PFCs) are mainly recommended as surface drainage layers on high-speed road-corridors and runway pavements. Permeability and sound attenuation characteristics are considered to be the indices for performance assessment of PFCs. One of the reasons for the loss of permeability in PFCs is densification under heavy traffic. But, resistance to ravelling too, is of main concern in the case of under-compacted PFCs. This paper summarises the details of laboratory investigation on the characterization of PFC mixes corresponding to four different gradations and two binder contents, for three levels of the Marshall compaction. The findings of the investigation suggest that the selection of the compaction level for PFC mix design should be based on the design traffic level, and the gradation selected. © 2009 Elsevier Ltd. All rights reserved.Item Effect of aggregate gradations on properties of porous friction course mixes(2010) Suresha, S.N.; George, V.; Ravi Shankar, A.U.This paper presents the study on effect of aggregate gradation on the mix design and performance properties of porous friction course (PFC) mixes. Six aggregate gradations were tested with due consideration to gradations specified for PFC or similar mixes by different agencies around the world. The PFC mixes were characterized for volumetric properties, permeability, unaged and aged abrasion loss, moisture susceptibility, and rutting resistance. The results were statistically analysed to identify the factors that significantly influence the properties of PFC mixes. Findings of the study clearly indicate that the gradations specified by various agencies will have significant effect on the design properties of PFC mixes, thus they are different. It also, helps in framing the Master aggregate gradation band for PFC mixes. Generally, permeability property is considered to be an optional parameter in the design. However, the findings of the present study recommended considering the permeability as one of the prime parameters in the design of PFC mixes. © RILEM 2009.Item Interface bond strength of ultra-thin whitetopping (UTW) and hot mix asphalt (HMA) composites by direct shear(ASTM International, 2017) Suresha, S.N.; Satish, D.Whitetopping is a portland cement concrete (PCC) overlay that is constructed on the top of existing bituminous or hot mix asphalt (HMA) pavement. The design and construction of UTW over HMA enables the composite to act as a monolithic layer. This article presents the findings of a laboratory study performed on interface shear strengths of UTW and HMA composites by direct shear approach. The objectives of the study were to evaluate the main effects of (i) different interface treatments, (ii) variation in the design binder content of HMA, and (iii) temperature conditioning and moisture conditioning on the interface shear strength. Based on the results of interface shear strength tests, the range of bond strength of UTW-HMA was found to be 0.22-1.29 MPa. Other factors like age of UTW, temperature conditioning, and moisture conditioning also had significant effects on the interface shear strengths of UTW-HMA composites. © Copyright 2017 by ASTM International.Item Evaluation of properties of nonfoaming Warm mix asphalt mixtures at lower working temperatures(American Society of Civil Engineers (ASCE) onlinejls@asce.org, 2017) Shiva Kumar, G.; Suresha, S.N.Warm mix asphalt (WMA) is a green technology which has the potential to replace hot mix asphalt (HMA) because it reduces greenhouse gas emissions and energy consumption by lowering the temperature at which asphalt mixtures are produced and placed. During the design process, evaluation of the mix design and mechanical properties of WMA mixtures is necessary. Therefore, the ability to quantify compactability would be very useful. This paper presents details on the evaluation of asphalt mix design, workability, and mechanical properties of asphalt mixtures modified with nonfoaming WMA additives at lower working (mixing and compaction) temperatures. Further, it seeks to provide a wider gap between mixing and compaction temperatures to ensure that WMA mixtures are suitable for longer haul distances. Asphalt mix design properties were evaluated by the Superpave method for various design gyrations (Ndes), and workability properties were evaluated in terms of Superpave gyratory compactor (SGC) densification indices using the Bahia and locking point methods. Mechanical properties such as resistance to moisture-induced damage were evaluated by the tensile strength ratio (TSR) approach, rutting resistance was evaluated by a laboratory wheel tracking test using a wheel rut tester (WRT), and flexural fatigue characteristics were evaluated by four point bending using a repeated load testing (RLT) machine. The effects of nominal maximumaggregate size (NMAS), working temperature, and type of mixture on the properties ofWMAmixtures were investigated. The experimental results were statistically analyzed to identify the major influencing factors and their significance. © 2017 American Society of Civil Engineers.Item Effects of coconut shell charcoal powder combined with SBS on rheological properties of asphalt binder(Elsevier Ltd, 2025) Rahul, M.S.; Anjani, H.; T S, P.; Bhanu V, U.; Suresha, S.N.Conventional asphalt binders often suffer from inadequate stiffness, elasticity, and aging resistance under high temperatures and heavy traffic conditions. This study addresses these limitations by utilizing coconut shell charcoal powder (CSCP), a carbon-rich, porous biochar derived from agricultural waste, along with styrene-butadiene-styrene (SBS) polymer to enhance the rheological performance and sustainability of VG-30 asphalt binder. CSCP, incorporated at 2 %, 4 %, and 6 % by weight, provides high surface activity and thermal stability that improve binder stiffness and aging resistance, while 1 % SBS enhances elasticity and recovery through its elastomeric network. Rheological tests using the dynamic shear rheometer (DSR), multiple stress creep recovery (MSCR), and linear amplitude sweep (LAS) on unaged, rolling thin-film oven (RTFO)-aged, and pressure aging vessel (PAV)-aged samples, supported by field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR) analyses, revealed that the dual-modified binder (CSMB6S1) achieved an optimal balance of stiffness and elasticity, exhibiting superior rutting resistance, fatigue life, and high-temperature stability. The results highlight the synergistic reinforcement between CSCP and SBS and demonstrate the potential of coconut shell–derived carbon as a sustainable modifier for high-performance asphalt pavements. © 2025 Elsevier Ltd.