This study evaluated soil properties and the impact of adding construction and demolition waste on pavement performance. Tests included water content, specific gravity, Atterberg\'s limit, sieve analysis, compaction, and California bearing ratio. Soil samples were mixed with 10%, 20%, 30%, and 40% construction and demolition waste.
Results Showed:
• Maximum dry density decreased from 1.88g/cc (0% waste) to 1.767 g/cc (40% waste).
• Optimum moisture content decreased from 11.95% (0% waste) to 11.08% (40% waste).
• California Bearing Ratio (CBR) increased from 3.82% (raw soil) to 14.04% (40% waste).
These values meet Indian Standard Codal specifications (IS 2720, 1983) for pavement subgrade and embankment construction. Therefore, construction and demolition waste can be an effective soil additive for pavement and embankment construction, potentially reducing pavement thickness per CBR design.
Introduction
I. INTRODUCTION
The explosive growth of population in recent decades, accompanied by the rapid urbanisation and socio-economic development has resulted in the need for more efficient and economical vehicular operations, which is reliant on the quality of road structures. The strength and shear characteristics of the pavement subgrade are essential for the adequate quality and appropriate performance of the road. It reinforces the social, economic, and cultural development of the country.
A. Soil Stabilization
Stabilization is the process of altering specific soil properties by different method in order to obtain an improved material that has all the desired engineering characteristics. Soils are generally stabilized to increase their strength and durability or to prevent erosion and dust formation; and thus creating a soil material or system that will withstand the designed use conditions and life of the project. The main objective of this study is to effectively stabilize the locally available subgrade in a cost-efficient manner.
B. Sub-grade
Sub grade is a lowermost part of road pavement structure, which acts as a stresstransmitting medium and disseminates the acting wheel load such that it aids in the prevention of shear and consolidated deformation. However, several researches have indicated that existing soils often do not fulfil the conventional requisites for the highway material. Even the soils that exhibits satisfactory characteristics for pavements construction can undergo changes in several attributes during construction and consequent operation, in which gradation is considered as most sensitive. It is therefore is essential to stabilize the soil. Recent years have witnessed several countries considering the reutilization of waste materials as a new construction material as a significant sustainable construction activity.
This study concentrates on reuse of recycled concrete aggregate as a partial replacement for soil in order to achieve stabilization. In recent times, with the increased demand for infrastructural development, raw materials and fuel, soil stabilization has gained a significant amount of emphasis.
With the availability of better research, materials and equipment, it has been emerging as a beneficial and cost- effective method for soil improvement.
C. Construction and Demolition Waste
The waste generated from construction, renovation, repair, and demolition of houses, large building structures, roads, bridges, piers, and dams is categorised under construction and demolition waste. It constitutes of wood, steel, concrete, gypsum, masonry, plaster, metal, asphalt, et\cetera. C&D waste can also contain hazardous materials such as asbestos and lead. Estimates vary, but commonly accepted statistics say that 15% to 20% of generated municipal solid waste originates from construction and demolition projects. Specifically, for India, the Building Materials Promotion Council (BMPC) estimates 1504.444 million tonnes of C&D waste annually, while its capacity is only that of 6,500 tonnes per day (TPD), which is barely 1% of the waste quantity produced.
The aim of this research is to determine the soil improvement capabilities of recycle aggregates obtained from demolition waste. The main cause of using demolition waste in place of other improvisation materials such as lime, bitumen etc is that these materials poseand more significant and direct damage to the environment.
II.MATERIALS USED AND METHODOLOGY
Construction and Demolition waste was used in powdered form, consisting of the following materials:
Broken concrete pieces
Sand
Bricks
Cement
Fly ash, etcetera.
Soil sample was collected from the Sitapur district (Banoga village). Initial tests were conducted on raw soil sample, followed by tests that were performed on the soil sample mixed it with construction and demolition waste in varying percentages (10%, 20%, 30%,and 40%).
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Conclusion
The study of strength characteristics of stabilization soil using construction and demolition waste show that there is a general decrease in maximum dry density (MDD)as well as optimum moisture content (OMC) of the soil sample.
The California Bearing Ratio of original soil sample is found to be 3.82%, which is sufficient for embankment (as per IS: 2720 Part 16, minimum for embankment 2%) but isnot sufficient for pavement subgrade (as per IS: 2720 Part 16, minimum for subgrade 6%).
Hence, construction and demolition waste is mixed with the soil for the purpose of improving the CBR value. Consequently, an increase in the CBR value is observed; withincreasing percentage of construction and demolition waste content in the soil. The CBRvalues corresponding to 10%, 20%,30% and 40% C&D waste are found to be 5.47%, 8.13%, 11.02% and 14.04% respectively; which also satisfy the aforementioned IS code recommendations.
Hence, we can justify the of use soil stabilised using construction and demolition waste for the purpose of pavement subgrade, as well as embankment design and construction. Itcan be adopted as an easily procurable and ecologically as well as fiscally advantageous soil stabiliser.
References
[1] IS 2720, Part 2, 3, 4, 5, 6, 7, 8 and 16
[2] Kamon, M., & Nontananandh, S. (2013). Combining Industrial Wastes with Lime forSoil Stabilization. Journal of Geotechnical Engineering.
[3] Tremblay H. et al (2002). Influence of the nature of organic compounds on fine soilstabilization with cement. Canadian Geotechnical Journal, 39, 535-546.
[4] Wright, W. & Ray, P. N. (2016). The Use of Fly Ash in Soil Stabilization. Universityof Southern California.
[5] “Use of recycled aggregates arising from construction and demolition waste in newconstruction applications.” RV Silva et al - Journal of Cleaner Production.
[6] “Stablization of weak subgrade soil using demolished concrete aggreagate” NunoCristelo, et al .
[7] Utilization of Construction and Demolition Wastes in Low-Volume Roads for RuralAreas in China Xiaoyang Jia, et al: Transportation research record.
[8] “Strength and Drainage Characteristics of Poor Soils Stabilized with ConstructionDemolition Waste.” Abhishek Sharma and Ravi, Geotechnical and Geological Engineering volume.
[9] “Use of recycled construction and demolition materials in geotechnical applications: Areview”, Castorina Silva Vieira, Paulo M. Pereira.
[10] “Effect of fly ash, construction demolition waste and lime on geotechnical
[11] Characteristics of a clayey soil: a comparative study” R. K. Sharma & J. Hymavathi,Environmental Earth Sciences.
[12] “Soil Stabilization Using Construction and Demolition Waste in Road Construction”S.P.Kanniyappan et al : Pramana Research Journal, 2022