Author: scizentox

Prof. S Shankar: Professor at National Instotue of Technology Warangal, India

1. Article Details

This article, titled Global research trends in full-depth reclamation for pavement engineering: a bibliometric analysis (1991–2025), was authored by P. Divya, S. Shankar, and Venkaiah Chowdary and published in Innovative Infrastructure Solutions, Volume 11, Article 511, on 19 August 2026. It is a review and bibliometric study covering 35 years of FDR research from 1991 to 2025. The study analyzes 83 peer-reviewed articles from Asia, North America, South America, Europe, and Africa. It focuses on chemical and bituminous stabilization in FDR, particularly stabilizer type, mix design, compaction, curing, performance criteria, and RAP incorporation.

2. Novelty

The novelty of this study lies in its comprehensive global bibliometric assessment of FDR research over a 35-year period. Rather than examining the performance of a single FDR material or rehabilitation project, the study maps the development of the entire research field. It identifies major contributing countries, regional preferences for stabilization methods, important research parameters, and recent research growth. The finding that nearly half of the identified publications were produced between 2020 and 2025 demonstrates the rapidly increasing research interest in FDR. The study therefore provides a valuable research map for understanding the evolution and future direction of FDR technology.

3. Impact

The study has considerable academic, engineering, and practical impact because it consolidates dispersed FDR research into a single comprehensive assessment. It identifies the United States as the leading contributor, followed by India, Georgia, China, and Canada, thereby showing the global development of FDR research. The comparison of cement and bituminous stabilization practices can help researchers and pavement engineers understand regional technology preferences. The study also provides a foundation for identifying research priorities and developing future experimental investigations. Its findings are particularly relevant to countries seeking economical and sustainable alternatives to conventional pavement reconstruction.

4. Originality

The originality of the article comes from its specific focus on the global research evolution of FDR rather than treating FDR only as one component of a general pavement-recycling review. The integration of research trends, geographical distribution, stabilization techniques, mix-design practices, curing, compaction, performance evaluation, and RAP utilization provides a broad perspective of the field. By covering literature from 1991 to 2025, the study also establishes a long-term perspective that helps distinguish established research areas from emerging topics. This makes the article useful as a reference framework for future FDR research.

5. Experimental Rigor

As a bibliometric review, the article does not involve laboratory experimentation or direct field testing; therefore, its rigor depends primarily on the systematic collection, screening, classification, and analysis of published research. The analysis of 83 peer-reviewed studies across five continents provides a substantial evidence base. The consideration of important technical variables such as stabilizer type, mix design, compaction, curing, performance, and RAP incorporation strengthens the technical relevance of the review. However, the study itself does not experimentally verify the performance of the stabilization techniques. Consequently, its conclusions should be interpreted as research-trend findings rather than direct experimental evidence of FDR performance.

6. Sustainability Impact

The study has strong sustainability significance because FDR enables the existing pavement and underlying materials to be reused during rehabilitation instead of being completely removed and replaced. This approach can reduce the consumption of virgin aggregates, minimize construction waste, decrease material transportation, and potentially reduce energy use and emissions associated with conventional reconstruction. The incorporation of RAP further supports resource conservation and circular-economy principles. By identifying developments in FDR stabilization and RAP utilization, the article highlights the potential of FDR to contribute to more sustainable pavement infrastructure.

7. Applicability

The findings are applicable to highway rehabilitation, road reconstruction, pavement maintenance, recycling of existing pavement materials, and sustainable infrastructure development. The review can help pavement engineers and researchers understand where different stabilization approaches have been adopted and which technical parameters require further investigation. Its findings are particularly useful for developing FDR mix designs, selecting suitable stabilizers, optimizing RAP utilization, and designing future laboratory and field studies. The research is therefore applicable to both academic research and practical pavement rehabilitation planning.

Research Portfolio

Dr. S. Shankar is an accomplished Civil Engineering academic and transportation engineering professional at the National Institute of Technology Warangal, Telangana, with extensive expertise in pavement engineering, low-volume roads, pavement materials, road maintenance, and sustainable transportation infrastructure. He holds a Ph.D. in Civil Engineering, M.Tech. in Transportation, and B.E. in Civil Engineering, and has developed a strong academic, research, consultancy, and professional service profile through teaching, sponsored research, technical consultancy, doctoral supervision, and engagement with government and professional organizations.

Online Profile

ORCID Profile

Scopus Profile

• Scopus Author ID: 57211683260
• ORCID: 0000-0001-6156-4625
• Documents: 37
• Citations: 204, from 173 citing documents
• h-index: 8

Dr. S. Shankar is associated with the Department of Civil Engineering, Transportation Division, National Institute of Technology Warangal, where he serves as an Associate Professor and has held leadership responsibilities including Head of the Transportation Division and Program Coordinator. His professional profile reflects substantial engagement with the Indian Roads Congress, Indian Society for Technical Education, Institution of Transportation Engineers, Indian Geotechnical Society, PMGSY technical agencies, and various academic and technical committees. His work also includes invited lectures, conference participation, peer reviewing, external examination, consultancy assignments, and technical training for road-sector professionals.

Education

Dr. S. Shankar completed his Ph.D. in Civil Engineering at the National Institute of Technology Warangal in 2012, following an M.Tech. in Transportation from NIT Warangal in 2006 and a B.E. in Civil Engineering from Vasavi College of Engineering, Hyderabad, in 2003. He also completed a Diploma in Civil Engineering from Government Polytechnic, Masab Tank, Hyderabad, in 2000 and his secondary education at St. Xavier’s High School, Suryapet, in 1996. His academic progression demonstrates a continuous specialization in civil and transportation engineering, particularly in pavement and rural-road systems.

Research Focus

His research focuses primarily on forensic investigation of pavement failures, low-volume road engineering, pavement analysis and design, pavement management and asset management, innovative and marginal materials, waste-material utilization, geosynthetics, soil stabilization, and emerging technologies for rural roads. His recent research particularly emphasizes sustainable pavement materials and recycled aggregates, including reclaimed asphalt pavement, recycled concrete aggregate, emulsified asphalt-treated bases, coir geotextiles, biomedical-waste-derived materials, bottom ash, flood-resilient pavements, full-depth reclamation, and environmentally responsible pavement maintenance strategies.

Experience

Dr. S. Shankar has built a long-standing academic and professional career at NIT Warangal, progressing through research, teaching, and faculty positions in Civil Engineering and Transportation Engineering. His responsibilities have included teaching undergraduate and postgraduate courses, supervising Ph.D., M.Tech., and B.Tech. research, managing laboratories and transportation facilities, coordinating consultancy activities, serving on institutional committees, organizing technical programmes, reviewing research papers, evaluating dissertations, and providing expert technical guidance to government agencies and engineering institutions. He has also contributed to PMGSY-related technical activities and consultancy projects involving pavement evaluation, road materials, traffic studies, pavement design, quality control, road signage, and infrastructure assessment.

Research Timeline & Activities

His research trajectory began with investigations into pavement performance, rural roads, subgrade strength, pavement evaluation, rutting, and pavement maintenance, and subsequently expanded toward sustainable and recycled pavement materials. From the 2010s onward, his work increasingly addressed coir geotextiles, reclaimed asphalt pavement, recycled concrete aggregates, cement- and emulsified-asphalt-treated bases, pavement deterioration modelling, pavement management, porous asphalt, and low-volume rural-road sustainability. More recent activities include research on biomedical waste incinerated ash, bottom ash, flood-resilient pavements, roller-compacted concrete, full-depth reclamation, rejuvenated asphalt binders, and sustainable pavement maintenance. He has also conducted numerous government-sponsored training programmes, workshops, webinars, and executive development programmes on rural-road design, construction, quality control, pavement management, and innovative materials.

Awards & Honors

Dr. S. Shankar has received recognition for his academic and professional contributions, including the Outstanding Faculty in Engineering Award from Venus International Foundation, Chennai, as well as Best Paper Awards in 2024 and 2025. His professional standing is further reflected through his membership in national and international technical organizations, participation in expert and advisory committees, service as a reviewer and scientific committee member for conferences and journals, invited lectures at academic and government programmes, and technical contributions to rural-road and pavement engineering initiatives.

Strengths for the Innovative Researcher Award

Innovative and Sustainable Pavement Research
Dr. S. Shankar demonstrates a strong and sustained research focus on innovative, sustainable, and resource-efficient pavement technologies. His work spans reclaimed asphalt pavement, recycled concrete aggregate, waste-derived materials, geosynthetics, soil stabilization, emulsified-asphalt-treated bases, full-depth reclamation, and flood-resilient pavements. This breadth reflects a clear commitment to developing alternatives to conventional pavement construction and rehabilitation.

Strong Research Continuity and Emerging-Technology Orientation
His research trajectory shows a progressive movement from conventional pavement performance and rural-road investigations toward advanced recycling, waste utilization, pavement management, and climate-resilient infrastructure. His recent involvement in full-depth reclamation and recycled pavement technologies demonstrates his ability to identify emerging research areas and contribute to evolving transportation-engineering practices.

Global Research Contribution in Full-Depth Reclamation
His co-authorship of the 2026 study Global research trends in full-depth reclamation for pavement engineering: a bibliometric analysis (1991–2025) represents a distinctive contribution to the FDR research community. The study systematically maps 35 years of international research, identifying geographical trends, stabilization practices, RAP utilization, and emerging research priorities. Its broad evidence base and global perspective provide a useful research framework for future investigators.

Research with Direct Engineering and Societal Relevance
A major strength of Dr. Shankar’s research is its strong connection between academic investigation and practical road engineering. His work addresses pavement failures, low-volume roads, pavement maintenance, asset management, rural-road development, material characterization, and rehabilitation. His consultancy, government engagement, technical training, and PMGSY-related activities further demonstrate the translation of research knowledge into practical engineering applications.

Leadership, Collaboration, and Capacity Building
Beyond individual research outputs, Dr. Shankar has contributed through doctoral and postgraduate supervision, technical consultancy, professional organizations, peer review, expert committees, invited lectures, workshops, and government-sponsored training programmes. His leadership in transportation engineering at NIT Warangal and engagement with professional and government institutions demonstrate his ability to build research capacity and disseminate innovative engineering practices. Collectively, these achievements establish him as a researcher whose work combines innovation, sustainability, practical impact, interdisciplinary relevance, and long-term contribution to transportation infrastructure.

Dr. Varun Parmar: Project Associate at CSK, HPKV, Palampur, India

1. Article Details

This research article, titled “Predictive modelling of soil organic carbon, carbon stocks, and fractions across elevation gradients in the dry-temperate region of North-West Himalaya,” was published by Varun Parmar and co-authors in Environmental Monitoring and Assessment on 14 August 2026. The study was conducted in Kinnaur district of Himachal Pradesh and focused on understanding the spatial variation of soil organic carbon (SOC), carbon stocks and carbon fractions across different elevation gradients. Soil samples were collected from 146 georeferenced locations representing four elevation zones. The researchers incorporated 24 environmental covariates related to topography, climate, soil and environmental conditions. Random Forest, Random Forest Regression Kriging and Ordinary Kriging were used to predict SOC distribution, followed by uncertainty analysis and fuzzy clustering for identifying carbon management zones. The study produced high-resolution 30-m SOC maps and demonstrated that SOC increased from 10.60 g kg⁻¹ at lower elevations to 19.72 g kg⁻¹ at higher elevations, while SOC stocks approximately doubled across the elevation gradient.

2. Novelty

The major novelty of this study is its integrated use of machine learning, geospatial interpolation, uncertainty assessment and carbon-management zoning to understand SOC dynamics in a complex Himalayan landscape. Unlike conventional studies that mainly examine the relationship between SOC and elevation, this research demonstrates that elevation functions largely as an indirect surrogate for changes in climate, topography and other environmental variables. The comparison of Random Forest, Random Forest Regression Kriging and Ordinary Kriging provides a stronger methodological basis for SOC prediction. The use of elevation-stratified modelling is another important feature because it attempts to reduce large-scale environmental heterogeneity. The generation of 30-m-resolution SOC maps and identification of carbon accumulation hotspots further increase the practical value of the research. The combination of carbon fractions with fuzzy clustering to develop two Carbon Management Zones makes the study particularly distinctive because it connects SOC prediction with spatially targeted management.

3. Impact

The study has important scientific, environmental and management implications for Himalayan ecosystems. Scientifically, it improves understanding of how climatic and topographic gradients influence the distribution and stability of soil carbon. Environmentally, the identification of high-carbon areas provides useful information for protecting important terrestrial carbon reservoirs. The finding that higher elevations contain greater SOC and more passive carbon pools suggests that these areas may play an important role in long-term carbon storage. The research can also contribute to climate-change mitigation by improving estimates of soil carbon stocks. From a management perspective, the high-resolution maps provide spatial information that can support soil conservation, ecosystem restoration and sustainable land-use planning. The study is particularly relevant to mountainous regions where conventional field-based soil assessment is difficult, costly and spatially limited.

4. Originality

The originality of the study comes from combining several complementary approaches into a single spatial carbon-assessment framework. Instead of treating SOC as a variable controlled simply by elevation, the research investigates the environmental processes represented by elevation and incorporates multiple environmental covariates into predictive models. The simultaneous assessment of SOC concentration, carbon stocks and carbon fractions provides a more comprehensive picture of soil-carbon dynamics. The study also goes beyond prediction accuracy by examining uncertainty calibration between Random Forest and Random Forest Regression Kriging. The development of Carbon Management Zones through fuzzy clustering is another original aspect because it converts scientific predictions into spatially explicit management information. Thus, the work is original not merely because it applies machine learning, but because it integrates prediction, uncertainty, carbon-pool characterization and management zoning within a Himalayan soil-carbon framework.

5. Experimental Rigor

The study demonstrates good experimental and analytical rigor through systematic georeferenced soil sampling across four elevation zones and the use of 24 environmental predictors. The comparison of multiple modelling techniques strengthens the reliability of the conclusions because the performance of advanced machine-learning models was evaluated against Ordinary Kriging. Random Forest and Random Forest Regression Kriging consistently performed better than Ordinary Kriging, indicating that nonlinear relationships between SOC and environmental variables are important in the study region. Model validation and uncertainty analysis provide additional confidence in the predicted spatial patterns. The use of elevation-stratified modelling further demonstrates an attempt to address environmental heterogeneity rather than applying a single model blindly across the entire landscape. Nevertheless, the use of 146 sampling locations in a highly heterogeneous mountainous region means that additional independent sampling and external validation could further strengthen the generalizability of the results.

6. Sustainability Impact

The research has considerable sustainability value because SOC is closely connected with soil quality, ecosystem functioning and climate regulation. Identifying areas with high carbon storage can help prevent degradation of important carbon reservoirs and guide conservation efforts. The distinction between more labile carbon pools at lower elevations and relatively passive carbon pools at higher elevations can support differentiated soil-management strategies. Maintaining SOC can contribute to improved soil structure, nutrient cycling, water retention and ecosystem resilience. The Carbon Management Zones provide a basis for moving from generalized land management toward location-specific conservation practices. In the context of the Himalaya, where ecosystems are sensitive to climate change, land-use pressure and environmental degradation, such spatially targeted approaches can contribute to long-term ecosystem sustainability.

7. Applicability

The methodology has strong potential for application in other mountainous and environmentally heterogeneous regions. The combination of field observations, environmental covariates, machine learning and geospatial modelling can be adapted for SOC assessment in other parts of the Himalaya and potentially other mountain ecosystems. The 30-m-resolution predictions can support digital soil mapping, carbon-stock assessment, ecological restoration and land-use planning. Government agencies, researchers and land managers could potentially use similar approaches to identify carbon-rich areas and prioritize conservation interventions. The methodology could also be incorporated into broader soil-carbon monitoring and climate-mitigation programmes. However, application to other regions should involve local calibration and validation because relationships between SOC, climate, vegetation, soil properties and elevation can vary considerably between ecosystems.

Research Portfolio

Dr. Varun Parmar is a Soil Scientist and Project Associate affiliated with CSK Himachal Pradesh Krishi Vishvavidyalaya (CSK HPKV), Palampur, Himachal Pradesh. He completed his PhD in Soil Science from CSK HPKV, Palampur, in August 2024. His research career is centered on understanding soil processes, soil health, soil carbon dynamics, nutrient management, soil microbiology, and sustainable agricultural systems. He has developed research expertise in the isolation, characterization, and identification of plant growth-promoting rhizobacteria, digital soil mapping, geospatial characterization of soil properties, and assessment of soil organic carbon and its fractions. His work also extends to high-altitude medicinal plants, essential oil production, conservation of Himalayan plant resources, and sustainable management of fragile mountain agroecosystems. He has contributed to several peer-reviewed research articles, book chapters, and national-level scientific conferences, with particular emphasis on soil quality, carbon dynamics, integrated nutrient management, and sustainable agricultural practices in the Himalayan region.

Online Profile

Scopus Profile

Dr. Varun Parmar is a researcher affiliated with CSK Himachal Pradesh Agriculture University, Palampur, India, with research interests spanning Soil Science, soil carbon dynamics, soil health, nutrient management, soil microbiology, digital soil mapping, and sustainable agricultural systems. His Scopus Author ID is 58640910100. His Scopus profile currently records 4 documents, 7 citations from 7 citing documents, and an h-index of 2. His publication record reflects interdisciplinary research focused particularly on soil quality, carbon dynamics, integrated nutrient management, soil microbiological properties, geospatial soil characterization, and sustainable agriculture in the Himalayan region. He also has an ORCID connection option associated with his Scopus author profile, supporting integration of his research outputs across scholarly platforms.

Education

Dr. Varun Parmar obtained his PhD in Soil Science from CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur, with the degree awarded on 17 August 2024. His doctoral and academic training provided him with comprehensive knowledge and practical experience in soil science, soil fertility, nutrient management, soil microbiology, soil carbon dynamics, and sustainable soil management. His academic work has been closely associated with agricultural soils of the North-West Himalayas, with particular emphasis on acid Alfisols, dry-temperate soils, soil organic carbon, nutrient transformations, and soil quality assessment. His academic background also supports his current interests in digital soil mapping, geospatial analysis, microbial characterization, and plant–soil interactions. He has additionally completed relevant certifications, as documented in his academic records.

Research Focus

Dr. Parmar’s current research focuses on the isolation, characterization, and identification of plant growth-promoting rhizobacteria from soil and their potential applications in sustainable agriculture and soil health management. A major component of his research interests is digital soil mapping (DSM), including the use of geospatial approaches, geostatistics, and machine-learning techniques for spatial prediction and characterization of soil properties. He is also interested in soil organic carbon dynamics, carbon stocks, carbon fractions, soil microbial properties, and the influence of nutrient-management practices on soil quality. His broader research interests include integrated nutrient management, soil fertility, sustainable agricultural practices, soil–plant–microbe interactions, conservation of soil resources, and climate-resilient agricultural systems. His research has a particular geographical emphasis on the diverse and environmentally sensitive agroecosystems of the North-West Himalayas.

Experience

Dr. Varun Parmar has developed research experience through academic research and project-based assignments in Soil Science, soil management, and Himalayan bioresource research. He worked as a Project Associate at CSIR–Institute of Himalayan Bioresource Technology (IHBT), Palampur, Himachal Pradesh, from 1 September 2025 to 31 July 2026. During this period, he contributed to research on high-altitude medicinal plants, including the development of Package of Practices (PoP) for medicinal plant cultivation and assessment of essential oil yield and quality. He was also involved in the collection, characterization, documentation, and ex-situ preservation of Fritillaria species from high-altitude regions of Himachal Pradesh. His field activities resulted in the systematic collection and characterization of Fritillaria germplasm from 20 different locations. His experience combines laboratory research, field experimentation, soil and plant sampling, data analysis, scientific documentation, conservation research, and dissemination of research findings.

Research Timeline & Activities

Dr. Parmar’s research journey reflects a progressive development of expertise across soil science, sustainable agriculture, soil carbon research, microbiology, geospatial analysis, and Himalayan plant-resource conservation. His earlier research activities included studies on nutrient management, soil fertility, crop productivity, profitability, and soil properties under different agricultural practices. He subsequently expanded his research into long-term soil carbon dynamics, soil microbial populations, phosphorus fractions, and integrated nutrient-management systems in acid Alfisols of the North-West Himalayas. His work later incorporated geospatial characterization and digital approaches for mapping soil properties and soil organic carbon across elevation gradients. Alongside soil research, he gained experience in high-altitude medicinal plant cultivation, essential oil quality assessment, and conservation of Fritillaria species. He has presented his research at national scientific conferences, including events organized by SCSI, and has contributed to scientific publications and books covering soil health, soil biotechnology, rhizosphere processes, biofilms, and ecosystem services.

Awards & Honors

Specific awards, medals, fellowships, or formal honors were not included in the information provided. Nevertheless, Dr. Parmar has established a strong record of academic and research achievements through completion of a PhD in Soil Science, publication of multiple peer-reviewed research papers, participation in national scientific conferences, and contribution to several scientific books and book chapters. His research has been published in internationally recognized journals covering soil science, environmental monitoring, plant biology, agricultural ecology, and soil and plant nutrition. His participation in scientific conferences and presentation of research on natural farming, sustainable crop production, soil organic carbon mapping, geostatistics, and machine-learning approaches further demonstrates his active engagement with the scientific research community.

Strength for a Young Researcher Award

1. Interdisciplinary and Innovative Research

Dr. Parmar demonstrates strong interdisciplinary research capability by integrating soil science, soil carbon dynamics, microbiology, geospatial science, machine learning and Himalayan bioresource conservation. His recent work combines Random Forest, geostatistical modelling, uncertainty analysis and fuzzy clustering to develop high-resolution soil-carbon maps, demonstrating an ability to apply advanced technologies to complex environmental problems.

2. Strong Contribution to Himalayan Soil and Carbon Research

A major strength is his focused contribution to understanding soil organic carbon, carbon stocks, carbon fractions and soil quality in the North-West Himalayas. His research addresses environmentally sensitive mountain ecosystems where soil properties vary substantially with elevation, climate and topography. His work provides scientifically valuable information for understanding and conserving Himalayan soil-carbon reservoirs.

3. Research with Direct Sustainability and Climate-Relevance

Dr. Parmar’s research has clear relevance to climate-change mitigation, soil conservation, sustainable agriculture and ecosystem resilience. His identification of carbon-rich areas and Carbon Management Zones can support targeted conservation and land-management strategies. His work therefore connects fundamental soil science with practical solutions for maintaining soil health and long-term carbon storage.

4. Diverse Field, Laboratory and Advanced Analytical Expertise

He has developed a broad research skill set spanning field sampling, soil and plant analysis, microbial characterization, geospatial data analysis, digital soil mapping, machine learning, geostatistics and scientific documentation. His experience also includes high-altitude medicinal plants and Fritillaria germplasm conservation. This combination of field-based research and advanced analytical approaches demonstrates considerable versatility for an early-career researcher.

5. Emerging Research Leadership and Future Potential

Despite being an early-career scientist, Dr. Parmar has established a research trajectory spanning soil health, nutrient management, soil microbiology, soil carbon, digital soil mapping and Himalayan bioresources. His PhD training, project-based research experience, peer-reviewed publications, scientific presentations and interdisciplinary collaborations provide a strong foundation for future independent research. His ability to translate advanced scientific methods into regionally relevant environmental and agricultural applications indicates high potential for continued research leadership and impact.