International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 11 Issue: 05 | May 2024
p-ISSN: 2395-0072
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AN INVESTIGATION ON THE EFFICIENCY OF STEEL SLAG ON EXPANSIVE SOIL AS SUBGRADE FOR FLEXIBLE PAVEMENTS Dr. D. Koteswara Rao1, Khandavilli Venkata Sri Rama Manohar2, B. Sowmya3 Bandarupalli V. S. M. Bharadwaj4, Yeluru Govindu Sai Sanjay5 1Professor, Head of the Department of Civil Engineering and OSD to the Hon’ble Vice Chancellor
JNTUK, Kakinada, Andhra Pradesh, India 2,3,4,5 Undergraduate Students, Department of Civil Engineering, University College of Engineering (A), JNTUK,
Kakinada, Andhra Pradesh, India ---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract - The technology used in road construction continually evolves to accommodate changing vehicular patterns, construction materials, and subgrade conditions. A significant portion of pavement failures is often linked to poor subgrade conditions, with expansive soil subgrades presenting particularly challenging issues. These soils are prone to swelling and shrinking, leading to cracks, especially during the dry seasons or years, which are termed verticals. The extensive damage caused to highways built over expansive soil subgrades results in substantial financial losses worldwide, reaching millions of dollars. In countries like India, where expansive soils are widespread, rerouting highways to avoid these materials is nearly impossible. From recent studies, it is observed that, solid waste materials such as rice husk ash, fly ash, waste tire rubber chips, etc., are used for this intended purpose. Hence, by using industrial by-products viz., Steel slag as an admixture in such problematic soils is economical and beneficial. In the present study, an attempt has been taken to use the steel slag as an admixture on improving the strength characteristics of expansive soil to suite it as a sub grade for flexible pavements.
developing remedial measures to control the failures in pavements laid on expansive soil subgrades. The Soil stabilization emerges as a practical solution among various methods to mitigate the problems associated with expansive soils, offering an effective means of improving soil properties.
Key Words: Expansive Soil, Steel Slag, Liquid Limit, Plasticity Index, Optimum Moisture Content, Maximum Dry Density, California Bearing Ratio, Flexible Pavement.
One method used for stabilizing the expansive soils involves the application of chemical additives, including lime, cement, and fly ash. This technique has proven successful in numerous projects, mitigating swelling, reducing soil plasticity, improving soil workability, and enhancing soil strength. Lime stabilization involves three main processes: water absorption and chemical binding during the hydration of unslaked lime (CaO) into slaked lime (Ca(OH)2), pozzolanic reactions between lime and clay minerals to bolster mechanical strength, and cation exchange between the additive and clay particles (Dr.D.S.V.Prasad and T.Yamini devi (2018))
Comprising a significant portion of clay-sized particles, this soil exhibits a color spectrum ranging from black to chestnut brown. On an average, expansive soils cover approximately 20% of total land area in India. These soils are conducive to dry farming and support the cultivation of crops such as cotton, rice, jowar, wheat, cereals, and vegetables, owing to their high moisture retention capacity. In semi-arid regions, over the past few decades, noticeable damages caused by the swelling and shrinking action of expansive soils have been observed, leading to the cracking and disintegration of channels, reservoir linings, pavements, building foundations, water lines, irrigation systems, sewer lines, and slab-on-grade structures.
1.INTRODUCTION Expansive soils are characterized by significant changes in volume due to fluctuations in soil moisture. The foundations laid on expansive soil beds facing significant damages because of swelling and shrinkage phenomena of expansive soil due to the variation in temperatures. Typically, pavements on expansive subgrade soils exhibit early signs of distress, leading to pavement failures. Expansive soils often possess unfavorable engineering properties, such as low bearing capacity, instability, and excessive swelling, posing significant challenges to civil engineering structures, especially in case of pavement sub grades and foundations. A Numerous researchers have conducted extensive studies to address these issues for
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One of the methods of treatment of expansive soil to make them fit for the construction purposes is called stabilization. According to Petry (2002), assortment of stabilizers can be grouped into:
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By-product stabilizers (Quarry dust, Fly Ash, Slag, Phosphor- gypsum, etc.)
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