Publications
Enhancing concrete's resistance to ASR by integrating metakaolin–carbon nanotube blends
Authors: R. K. Singh et al.
Cement and Concrete Composites • 2024
Proposes metakaolin–CNT blends as a strategy to mitigate alkali–silica reaction in concrete. The work shows that combining metakaolin with well-dispersed CNTs improves alkali binding and modifies the C-S-H composition in the interfacial transition zone, significantly reducing expansion below ASTM C1567 limits while preserving modulus and tensile energy absorption after ASR exposure.
On the interactions of carbon nanotubes with metakaolin cementitious binders: Effects on ITZ, modulus and toughness
Authors: R. K. Singh et al.
Construction and Building Materials • 2023
Investigates how small dosages of CNTs influence the mechanical response and microstructure of metakaolin-modified mortars. Results show substantial gains in flexural strength, Young’s modulus, and post-crack toughness when 0.1 wt% CNTs are added to 20% metakaolin mixes, linked to a denser ITZ and altered C-S-H chemistry with lower Ca/Si ratios.
Multiscale toughening mechanism in hybrid fiber reinforced cement-based nanocomposites
Authors: R. K. Singh et al.
Springer (Book Chapter) • 2024
Evaluates hybrid reinforcement systems combining carbon nanofibers and polypropylene microfibers in cementitious composites. Using fracture mechanics tests on notched prisms, the study demonstrates large increases in critical stress intensity, fracture toughness, and toughness indices compared to single-scale reinforcement, and explains the multiscale crack-arrest mechanisms responsible for the improved performance.
CO₂ utilization for cementitious materials – A review
Authors: R. K. Singh et al.
KSCE Journal of Civil Engineering • 2024
Reviews current approaches to utilizing COâ‚‚ within cementitious systems, including COâ‚‚ curing, carbonation-activated SCMs, carbonated binders and aggregates, and injection of COâ‚‚ into fresh concrete or mixing water. Discusses potential for simultaneous performance improvement and COâ‚‚ sequestration, along with remaining challenges related to durability, process optimization, and large-scale deployment.
Carbon capture and utilization for ready-mix concrete
Authors: R. K. Singh et al.
BETON 2023 Ready Mixed Concrete Congress • 2023
Explores practical routes for integrating COâ‚‚ capture and utilization technologies into ready-mix concrete production. Highlights the role of SCMs, nanomaterials, and carbon-negative additives such as biochar in increasing COâ‚‚ uptake and influencing hydrate polymorphs, while outlining pathways toward carbon-neutral or carbon-reduced concrete mixtures.