Faculty Publications

Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736

Publications by NITK Faculty

Browse

Author: search.filters.author.Durga Prashanth, L.Has files: No

Search Results

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    A model study on accelerated consolidation of coir reinforced laterite and blended shedi soil with vertical sand drains for pavement foundations
    (2012) George, V.; Santosh, G.; Hegde, R.N.; Durga Prashanth, L.; Gotamey, D.; Ravi Sankar, A.U.
    Sub-grade soils of lateritic origin are frequently encountered in the construction of highway embankments in various regions of India, often comprise intrusions of soft lithomargic soils that result in large settlements during constructions, and differential settlements at later stages. This necessitates the use of appropriate soil improvement techniques to improve the load-carrying capacity of pavements. Coir is a natural fiber that can be used in place of geosynthetics and geogrids, and it is biodegradable and environment friendly. This work deals with the accelerated consolidation of un-reinforced and coir-reinforced laterite and blended lithomargic soils, provided with three vertical sand drains. The load-settlement characteristics were studied for various preloads ranging from 50kg (0.0013 N/mm2) to 500kg (0.013N/mm2) using circular ferro-cement moulds. It was observed that at lower preloads up to 300kg, the relative increase in consolidation (Cr) for randomly reinforced soil with vertical drains was significantly higher than that of un-reinforced soil without vertical drains. Also, the Cr for un-reinforced soil with vertical drains was quite higher than that of un-reinforced soil without vertical drains, with values above 38.71%. However, in the case of higher preloads of 450kg and 500kg, the Cr for randomly reinforced soil with vertical drains was insignificant, and the Cr for un-reinforced soil with vertical drains remained slightly higher at around 9.59% for similar comparisons. The aspect-ratio of coir fibers used was 1: 275. © 2012 Cafet-Innova Technical Society. All rights reserved.
  • No Thumbnail Available
    Item
    A study on the effect of rejuvenators in reclaimed asphalt pavement based stone mastic asphalt mixes
    (Springer, 2019) Durga Prashanth, L.; Palankar, N.; Ravi Shankar, A.U.
    The present paper focuses on the behavior of Stone Mastic Asphalt (SMA) mixes incorporating rejuvenated Reclaimed Asphalt Pavement (RAP) materials. The RAP materials were tested for its physical properties and later were rejuvenated using various rejuvenators such as waste cooking oil, waste engine oil and shredded plastics. The rejuvenated RAP materials were incorporated in the SMA mixes at various replacement levels i.e. 0%, 30%, 50% and 70% (by weight). Various binder properties such as viscosity, rheological properties and chemical composition were evaluated for the aged and rejuvenated material. The rejuvenators were incorporated at different dosage levels i.e. 2%, 4% and 6% (by weight of binder). The optimal rejuvenation dosage for each type of rejuvenator was identified and mix design for the SMA was optimized for evaluating its physical and mechanical properties. Based on the results, the optimum rejuvenator dosage was identified at 6% for waste cooking oil and waste engine oil, while 2% for shredded plastics. It was observed that the addition of rejuvenators improved the performance of RAP based SMA mixes. © 2019, Chinese Society of Pavement Engineering. Production and hosting by Springer Nature.
  • No Thumbnail Available
    Item
    A Study on Elastic Deformation Behavior of Steel Fiber-Reinforced Concrete for Pavements
    (Springer, 2019) Chandrashekar, A.; Palankar, N.; Durga Prashanth, L.; Mithun, B.M.; Ravi Shankar, A.U.
    The present study discusses the experimental investigation of steel fiber-reinforced concrete slabs on ground under wheel load with the objective of understanding the stress behavior when subjected to central and edge wheel loading. The steel fiber-reinforced fly ash concrete slabs of 900 mm × 900 mm, 150 mm thickness were investigated in this study. Strain gauges and data acquisition system were used to measure the strains at the center and the edge of the slab under the action of the load. The load versus strain relationship under central and edge loading for reference concrete and steel fiber fly ash concrete showed a linear variation even up to the pressure of 2.5 MPa, which is much beyond the conventional tyre inflation pressure of 0.8 MPa. The load versus strain graphs clearly signify the higher modulus of elasticity of fly ash steel fiber-reinforced concrete. The stresses were calculated using IITRIGID software and ANSYS software and were found matching significantly. The value of modulus of elasticity of fly ash steel fiber-reinforced concrete (FS) using ANSYS model for experimental values of load and strains measured was approximated to 34,000 N/mm2 and was found to closely match with the experimentally obtained modulus of elasticity. No significant effect of Poisson’s ratio of concrete on load–strain characteristics was observed within the range 0.15–0.2 of concrete. © 2019, The Institution of Engineers (India).