Browsing by Author "Talkeri, H.T."

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Alkali Activated Concrete Mixes with Processed Reclaimed Asphalt Pavement
(Springer, 2025) Talkeri, H.T.; Sagar, M.H.; Raghuram, K.C.; Hemanth, D.; Kondeti, C.; Preethi, S.
This study evaluates the feasibility of using processed reclaimed asphalt pavement for alkali-activated slag concrete (AASC) mixes. A novel alkali and alkali-abrasive method is developed to remove the stiff asphalt layer and puncture the asphalt film engulfed in the Reclaimed Asphalt Pavement (RAP) material. The hydrophobic layer of asphaltic aggregate exhibits poor bond characteristics, significantly affecting concrete strength properties. The influence of processing methods on concrete characteristics was investigated and compared with control mixes. Incorporating processed RAP improved the workability properties and cohesiveness of mixes at different sodium hydroxide concentrations. Beneficiation of processed RAP by alkali and alkali-abrasive techniques increased strength characteristics by 20% and 42% respectively compared to control mixes. Processing RAP using the alkali technique improved workability properties slightly, while the alkali-abrasive technique significantly improved fresh and hardened characteristics due to the removal of the stiff asphalt layer. Fatigue test data were analyzed using a two-parametric Weibull distribution for survival probability. The analysis established that fatigue life at various stress levels for AASC with processed RAP can be described using Weibull distribution. Goodness-of-fit tests validated the distribution model for the statistical description of the fatigue life of various mixes. Based on laboratory tests, alkali-activated mixes developed with processed RAP satisfy requirements for pavement-quality concrete. © The Author(s), under exclusive licence to Chinese Society of Pavement Engineering 2025.
Unmodified Bitumen in SMA: A Sustainable and Cost-Effective Approach
(Springer Science and Business Media Deutschland GmbH, 2025) Arun, U.; Chinnabhandar, R.K.; Talkeri, H.T.; Yatish, R.G.; Ravishankar, A.U.
Stone Matrix Asphalt (SMA) is a Hot Mix Asphalt (HMA) mixture consisting of a discontinuous aggregate gradation characterised by a high coarse aggregate content (between 70 and 80%), a high percentage of binder (typically between 6 and 7%) and a filler content as high as about 10%. SMA has an aggregate skeleton which imparts high strength and rutting resistance to the mixture. The high binder content though provides the mixture with durability, it also drains through the void spaces in the aggregate skeleton during production, transportation and placement of the mixture in the field. Hence, to reduce the drainage of bitumen and bitumen mortar, the SMA guidelines suggest using a modified bitumen or pelletised cellulose fibres in the mixture when a conventional bitumen such as Viscosity Graded (VG 30) is used. However, the production of cellulose fibres is not only expensive but also requires trees to be cut since cellulose is obtained from plant sources leading to deforestation. Due to the high cost of Polymer Modified Bitumen (PMB), the SMA mixtures prepared with the modified bitumen are also expensive. Hence, the present study focuses on the laboratory evaluation of SMA mixes using a conventional Viscosity Graded bitumen (VG 40) without the use of pelletised cellulose fibres. The results indicated that the susceptibility of mixtures to drainage of binder and/or binder mortar was within the permissible limit of 0.3% by weight of the mixture. The mechanical and moisture susceptibility tests conducted on compacted specimens indicated that the performance is comparable to that of the mixtures prepared using PMB. Further, it was noted that only the grades of bitumen softer than VG 40 required cellulose fibres to reduce drain-down. The study also revealed a reduction in cost due to not using cellulose fibres with VG 40 bitumen or modified bitumen, which makes it more environmentally friendly and sustainable. Â© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.
Utilization of Ferrochrome and Recycled Concrete Aggregates for Sustainable Pavement Base Layersâ€”A Laboratory Study
(Springer Science and Business Media Deutschland GmbH, 2025) Chiranjeevi, K.; Kumar, D.H.; Yatish, R.G.; Talkeri, H.T.; Mulangi, R.H.; Ravi Shankar, A.U.
The paramount importance of incorporating alternative aggregates cannot be overstated, as it plays a pivotal role in resource conservation, sustainability promotion, and efficient waste management. This study focuses on the utilization of ferrochrome aggregate (FCA) and recycled concrete aggregate (RCA) within cement-treated base layers, aiming to entirely substitute natural coarse aggregate (NCA). The research meticulously fabricated cement-treated recycled and ferrochrome aggregate (CTRFA) samples with cement contents of 3, 5, and 7%. These specimens incorporated varying blends of RCA and FCA, ranging from 0 to 100%. In this investigation, strength properties such as unconfined compressive strength (UCS), flexural strength, elastic modulus, and indirect tensile strength (ITS) were performed alongside durability. The experimental results indicated that the cement content exerted a more pronounced influence on both strength and durability. The CTRFA mixes containing 50% RCA, 50% FCA, and 5% cement meet IRC 37 2018 strength and durability standards and can be used as a base layer for flexible pavement instead of conventional cement-treated base (CTB). Â© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.