Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
2 results
Search Results
Item Laboratory Investigation of Lateritic Soil Stabilized with Arecanut Coir Along with Cement and Its Suitability as a Modified Subgrade(Springer Science and Business Media Deutschland GmbH, 2023) Chethan, B.A.; Lekha, B.M.; Ravi Shankar, A.U.If a pavement is constructed on weak soil, its lifespan drastically reduces due to the low strength induced by moisture-induced destresses. Such soils may undergo considerable changes in volume. In order to modify these properties, soil stabilization can be done. By stabilizing the soil along with the improvement in strength, its durability can be increased. Stabilization may be of chemical or mechanical type. In this investigation, lateritic soil was stabilized using 0.2–1% arecanut coir, and its compaction characteristics were evaluated. The lateritic soil is found to be nondurable. The reinforcement alone could not improve the strength and durability effectively. Therefore, 3% binding agent ordinary Portland cement (43 grade) was added to the mix. Due to cement stabilization, UCS and CBR values were improved, and the optimum values were observed at 0.6% arecanut coir dosage. The addition of cement has resulted in a change in silica, alumina, and calcium oxide contents, thereby contributing to the formation of hydration products. The samples with 1% coir and cement have completed 12 wet–dry cycles, but the weight loss observed was >14%. All the specimens showed low soil loss under freeze–thaw cycles. The performance of cured specimens under fatigue loading was satisfactory. Since the specimens could not pass wet–dry durability criteria, they can be considered for modified subgrade. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Effect of Electrolyte Lignin and Fly Ash in Stabilizing Black Cotton Soil(Springer US, 2015) Lekha, B.M.; Goutham, G.; Ravi Shankar, A.U.Subgrade is one of the important layers of any pavement. It must be able to support loads transmitted from pavement structure without excessive deformation under adverse climatic and traffic conditions. In this investigation, laboratory studies were carried out to evaluate the influence of a commercial electrolyte lignin stabilizer (ELS), fly ash (FA) and a combination of both, on black cotton (BC) soil procured from North Karnataka region in India. Basic geotechnical and engineering properties like unconfined compressive strength (UCS), California bearing ratio (CBR), etc. were determined for both untreated and treated soil. Dynamic repeated load test was conducted to examine the fatigue behaviour of the soil. Durability of the soil was checked by wet-dry (WD) and freeze-thaw (FT) cycle tests, and swelling properties by free swell index test. From the studies, it was observed that consistency limits, dry density, UCS and CBR values were improved for treated soil, with curing periods of 1, 7 and 28 days. Weight loss in FT test was less than 14 % for 12 cycles, which ensures that the stabilized soil has become durable. But none of the samples were observed to be withstanding above five cycles in wet-dry test. Soil stabilized with ELS and FA showed better results compared to soil with only ELS. Swelling was reduced to a great extent with 28 days curing period for the former one. From the experimental results, it can be concluded that this chemical can be used as a stabilizer for existing BC soil in site to enhance its subgrade strength. © 2015, Springer New York.