The Effect of CKD and RAP on the Mechanical Properties of Subgrade Soils
Anbar Journal of Engineering Sciences,
2022, Volume 13, Issue 1, Pages 98-107
AbstractThe construction of pavement layers on subgrade soil with good characteristics decreases the thickness of these layers, which in turn lowers the cost of building and maintaining roadways. However, it is impossible to avoid constructing pavements on unsuitable subgrade due to a number of limitations. Using conventional additives like lime and cement to improve subgrade properties results in additional costs. As a result, utilizing by-products (cement kiln dust and reclaimed asphalt pavement) in this field has benefits for the environment, economy, and technology. Large amounts of cement kiln dust (CKD), a by-product material, are produced in Portland cement factories. On the other hand, large amounts of reclaimed asphalt pavement (RAP) are accumulated as a result of the rehabilitation of old roads. This paper discusses using CKD and RAP to improve the characteristics of poor subgrade layers by conducting a series of Unconfined Compressive Strength (UCS) and California Bearing Ratio (CBR) tests on samples of natural soil and soil stabilized with different percentages of CKD and RAP with different curing times to investigate their impacts on soil properties. The curing was carried out by wrapping the stabilized samples with several layers of nylon and then placing them in plastic bags at room temperature. The compaction results illustrated that the addition of CKD increases OMC and decreases MDD, in contrast to RAP, which decreases OMC and increases MDD. The addition of CKD and RAP led to a significant and unexpected increase in the CBR values. The results show that the soaked and unsoaked CBR values improve from 3.4% and 12.1% for natural soil to 220.1% and 211%, respectively, after adding 20% CKD and curing the samples for 28 days. Also, the addition of 25% RAP to soil-20% CKD blend increased the soaked and unsoaked CBR values to 251% and 215%, respectively. All the additions resulted in a significant reduction in swelling.
 Ibrahim, S.F., G.G. Sofia, and A.I. Kareem, Experimental study on geogrid-reinforced subbase over soft subgrade soil under repeated loading. Journal of Engineering and Development, 2012. 16(3): p. 218-240.
 Davidovits, J., False values on CO2 emission for geopolymer cement/concrete published in scientific papers. Technical paper, 2015. 24: p. 1-9.
 Rahman, M., S. Rehman, and O. Al-Amoudi, Literature review on cement kiln dust usage in soil and waste stabilization and experimental investigation. International Journal of Research and Reviews in Applied Sciences, 2011. 7(1): p. 77-87.
 Elbaz, A., et al., Review of beneficial uses of cement kiln dust (CKD), fly ash (FA) and their mixture. J. Mater. Environ. Sci, 2019. 10(11): p. 1062-1073.
 Miller, G.A. and M. Zaman, Field and laboratory evaluation of cement kiln dust as a soil stabilizer. Transportation Research Record, 2000. 1714(1): p. 25-32.
 Rimal, S., R.K. Poudel, and D. Gautam, Experimental study on properties of natural soils treated with cement kiln dust. Case Studies in Construction Materials, 2019. 10: p. e00223.
 Shukla, V. and S. Tiwari, Improvement of pavement soil subgrade by using cement kiln dust. International journal for research in Applied Science & Engineering Technology (IJRASET), 2019. 7: p. 2341-2345.
 Magar, S., et al., Applications of reclaimed asphalt pavement in India–A review. Journal of Cleaner Production, 2021: p. 130221.
 Maignien, R., Survey of research on laterites. Humid Tropics Research Programme, UNESCO, 1964.
 Akinwumi, I., Plasticity, strength and permeability of reclaimed asphalt pavement and lateritic soil blends. International Journal of Scientific & Engineering Research, 2014. 5(6): p. 631-636.
 Saride, S., et al., Evaluation of fly ash treated reclaimed asphalt pavement for base/subbase applications. Indian Geotechnical Journal, 2015. 45(4): p. 401-411.
 Kwad, N.F., A.H. Abdulkareem, and T.M. Ahmed. The Effect of Fly Ash Based Geopolymer on the Strength of Problematic Subgrade Soil with High CaO Content. in Proceedings of the 9th International Conference on Maintenance and Rehabilitation of Pavements—Mairepav9. 2020. Springer.
 Jala, S.K. and P. Sharma, Effect of cement kiln dust and RBI grade 81 on engineering properties of plastic clay, in Recycled Waste Materials. 2019, Springer. p. 37-49.
 Mustapha, A., et al., Stabilization of A-6 lateritic soil using cold reclaimed asphalt pavement. International Journal of Engineering and Technology, 2014. 4(1): p. 52-57.
 Ogunrinde, E., T.E. Adejumo, and A. Amadi. Development of an Empirical Model for A-6 Soil Stabilized with Reclaimed Asphalt Pavement. 2020. Proceedings of 2nd International Civil Engineering Conference, Federal ….
 Adhikari, S., M.J. Khattak, and B. Adhikari, Mechanical characteristics of Soil-RAP-Geopolymer mixtures for road base and subbase layers. International Journal of Pavement Engineering, 2020. 21(4): p. 483-496.
 Salahudeen, A., A.O. Eberemu, and K.J. Osinubi, Assessment of cement kiln dust-treated expansive soil for the construction of flexible pavements. Geotechnical and geological engineering, 2014. 32(4): p. 923-931.
 Anwar Hossain, K.M., Stabilized soils incorporating combinations of rice husk ash and cement kiln dust. Journal of Materials in Civil Engineering, 2011. 23(9): p. 1320-1327.
 Upma, J. and S. Kumar, Effect of Cement Kiln Dust and Chemical Additive on Expansive Soil at Subgrade Level. International Journal of Innovative Research in Science, 2015. 4(5): p. 3795-3767.
 Edeh, J., A. Eberemu, and A. Abah, Reclaimed asphalt pavements-lime stabilization of clay as highway pavement materials. Journal of Sustainable Development and Environmental Protection, 2012. 2(3): p. 62-75.
 ASTM-D422 2007. Standard Test Method for Particle-Size Analysis of Soils. ASTM International, West Conshohocken, PA.
 ASTM-D1557 2012. Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft3 (2,700 kN-m/m3)). ASTM International, West Conshohocken, PA.
 ASTM-D2166 2013. Standard Test Method for Unconfined Compressive Strength of Cohesive Soil. ASTM International, West Conshohocken, PA.
 ASTM-D2487 2017. Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System). ASTM International, West Conshohocken, PA.
 ASTM-D4318 2017. Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils. ASTM International, West Conshohocken, PA.
 ASTM-D854 2014. Standard Test Methods for Specific Gravity of Soil Solids by Water Pycnometer. ASTM International, West Conshohocken, PA.
 ASTM-D1883 2016. Standard Test Method for California Bearing Ratio (CBR) of Laboratory-Compacted Soils. ASTM International, West Conshohocken, PA.
 Salahudeen, A., A. Eberemu, and K. Osinubi, Assessment of cement kiln dust-treated expansive soil for the construction of flexible pavements. Geotechnical and geological engineering, 2014. 32(4): p. 923-931.
 Ghanizadeh, A.R., M. Rahrovan, and K.B. Bafghi, The effect of cement and reclaimed asphalt pavement on the mechanical properties of stabilized base via full-depth reclamation. Construction and Building Materials, 2018. 161: p. 165-174.
 Little, D.N., Stabilization of pavement subgrades and base courses with lime. 1995.
 Hatipoglu, B., T.B. Edil, and C.H. Benson, Evaluation of base prepared from road surface gravel stabilized with fly ash, in GeoCongress 2008: Geotechnics of Waste Management and Remediation. 2008. p. 288-295.
 Alhaji, M.M. and A. Musa, Effect of reclaimed asphalt pavement stabilization on the microstructure and strength of black cotton soil. 2018.
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