Scholarly Publication

Permanent URI for this collection

https://kwasuspace.kwasu.edu.ng/handle/123456789/190

Browse

Recent Submissions

Now showing 1 - 5 of 58
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Comparative Study of Geotechnical Assessment of Highway Subgrade Using In Situ DCPT and Laboratory Engineering Parameters
    (2024-05-12) C. A. Oyelami; O. O. Owoyemi; O. A. Ojo; A. Salako
    A comparative study of the geotechnical assessment of subgrade soils using in situ Dynamic Cone Penetrometer (DCP) Test and laboratory tests were carried out. The study was aimed at establishing the suitability of selected tropical soils as subgrade materials using the conventional laboratory test and in-situ DCPT method. The study involved sampling a total of 15 soil samples taken in a hand-dug pit at a minimum depth of 0.5m along Osogbo-Ilobu road. The in-situ test involved the use of a DCP in estimating the in-situ California Bearing Ratio (CBR) of the soil at 100m intervals through the 1.5 km stretch of the road. Laboratory tests carried out includes the grain size analysis, hydrometer test, Atterberg limits and specific gravity, CBR, permeability and Unconfined Compressive Strength (UCS). The results revealed a well-graded soils which are mostly clayey and silty sand (SC & SM) according to the Unified Soil Classification System (USCS) and A-2-4, A-2-6 to A-7 category of the American Association of State Highway and Transportation Officials (AASHTO) classification. The coarse fraction ranged between 48.3 - 90.5 % and fine fraction between 9.5 - 44.6 %. The UCS ranged from 148.8 - 214.5 kPa; unsoaked CBR from 54 – 148 %; soaked CBR from 42 – 106 %, reduction in strength due to soaking between 2.8 and 31.1 %; DCPT estimated CBR between 70 and 185. Conclusively, the soils were fairly suitable as subgrade, except for the clay contents in them, accounting for a very low rate of permeability which may be responsible for ponding and excessive soaking of the subgrade.
  • Thumbnail Image
    Item
    Experimental Study of Use of Waste Glass for Sustainable Stabilization of Highway Foundation Soils
    (2024-11-27) Ejikunle O.B; Owoyemi O.O; Afolagboye L.O
    Recycling waste glass for subgrade soil improvement not only contributes to the development of sustainable and resilient highways but also mitigates the environmental impact of the vast quantities of glass generated daily. This study examines the potential of using waste glass to enhance the geotechnical properties of soil intended for highway subgrade applications. Soil sample was obtained from a borrow pit in Oyun, Southwestern Nigeria, where lateritic soils are quarried for construction purposes. The mineralogical and geochemical properties of the natural soil were analyzed using X-ray diffraction (XRD) and X-ray fluorescence (XRF). Pulverized waste glass underwent grain size distribution analysis, and the soil samples were mixed with waste glass in proportions of 0.5%, 1%, 1.5%, and 2% by weight. The impact of waste glass powder addition on Atterberg limits, linear shrinkage, compaction parameters, swell potential, and both soaked and unsoaked California Bearing Ratio (CBR) was investigated. The aging effect on the CBR of the stabilized samples was assessed by repeating the soaked CBR tests after 7, 14, and 21 days. Results indicated that the liquid limit, plastic limit, plasticity index, linear shrinkage, swell potential, and of the stabilized soils decreased with increasing glass content. Conversely, the maximum dry density and both soaked and unsoaked CBR values increased, while the optimum moisture content decreased with higher glass content. The stabilized soils maintained their strength even after 21 days of soaking. Waste glass, even at a 0.5% inclusion by weight, acts as an effective cementing agent, improving soil properties for highway foundations
  • Thumbnail Image
    Item
    Effects of elevated temperature and treatment duration on selected index and engineering properties of lateritic soils
    (2024-12-12) Lekan Olatayo Afolagboye, Olubunmi Oluwadare Owoyemi, Yusuf Ademola Abdu‑Raheem, Aderemi Sunday Adeoye
    Lateritic soils are important to various engineering applications, especially in tropical regions, where they serve as key components in road construction, embankments, and other geotechnical structures. This study investigated the com- bined effects of elevated temperature and heating duration on the index and engineering properties of lateritic soils derived from two distinct parent rocks (charnockite and quartzite) in Ado-Ekiti, Nigeria. Disturbed lateritic soil samples were heated in a furnace at various temperatures (100, 200, 300, and 400 °C) for two designated durations (2 and 3 h). Standard geotechnical tests were conducted to evaluate Atterberg limits, compaction parameters, and unconfined compressive strength. The results showed that elevated temperature led to a decrease in the plastic limit, liquid limit, plasticity index, optimum moisture content (OMC), and UCS for both soils, though the extent varied between the two parent rocks. For instance, at 400 °C for 3 h, the plasticity index decreased by 47.82% for charnockite-derived soil and 55.22% for quartzite-derived soil. At the same temperature for 2 h, it decreased by 38.79% for charnockite-derived soil and 48.92% for quartzite-derived soil. Similarly, UCS decreased by 29.83% for charnockite-derived soil and 25.97% for quartzite-derived soil at 400 °C for 3 h, while at 400 °C for 2 h, UCS decreased by 21.20% for charnockite-derived soil and 23.48% for quartzite-derived soil. Conversely, maximum dry density (MDD) increased with temperature, rising by up to 20.64% for charnockite-derived soil and 14.66% for quartzite-derived soil at 400 °C for 3 h, and by 18.29% for charnockite-derived soil and 12.62% for quartzite-derived soil at 400 °C for 2 h. Longer heating durations (3 h) generally caused more pronounced changes in soil properties compared to shorter durations (2 h). For instance, OMC decreased by 13.41% for charnockite and 14.18% for quartzite at 400 °C for 3 h compared to a 2-h duration. Statistical analyses indicated that temperature had a significant influence on most properties, while the effect of heating duration was less consistent. These findings highlight the need to consider both temperature and heating duration when evaluating the engineering behavior of lateritic soils exposed to elevated temperatures. Practical implications include potential adjust- ments in construction practices and design parameters for road construction and embankments in regions prone to high temperatures, such as those experiencing frequent forest fires.
  • Thumbnail Image
    Item
    Geochemistry and Mineralogy of Maastrichtian Coals from the Anambra and Gongola Basins of Nigeria: Implications for Coal Quality, Resource Potential, and Agglomeration Characteristics
    (Journal of Economic Geology, 2024-06-22) Ayoola Yusuf Jimoh; Mariam Bolaji; Jimoh Ajadi; Shakirat Mustapha Aminu; Mutiu Adelodun Akinpelu
    Anambra and Gongola basins are part of the sedimentary inland basins in Nigeria characterized by fossil fuels and in response to its present energy problem, Nigeria has shifted its power generating focus to coal. The studied coals were obtained from two localities, namely Ankpa and Maiganga in Kogi and Gombe States, respectively. The coals were investigated to determine its quality in terms of use and resource potential. The coals were analyzed by proximate, ultimate, elemental, mineralogy and scanning electron microscopy-energy dispersive spectrometry analyses. The objectives of the study are to determine the coals cokability, rank, paleoenvironments, hydrocarbon potential, and slagging tendency. The average values of moisture content, ash, volatile matter, and fixed carbon are 5.54%, 16.42%, 48.45%, and 30.71%, respectively, for Ankpa coals, while Maiganga recorded 10.68%, 8.60%, 44.33%, and 36.41%, indicating high volatile subbituminous non-coking coals that are optimum for combustion and electric power generation. The Van Krevelen plot based on the H/C vs. O/C showed Type IV kerogen. The XRD results, correlation plots, and Detrital Authigenic Index (DAI) values of 7.49 and 13.49 in Ankpa and Maiganga coals, respectively, indicated that Ankpa coals are enriched in authigenic minerals like quartz, pyrite, and calcite, while kaolinite and quartz were probable detrital minerals in the Maiganga coals. The agglomeration of the coals deduced by Base/Acid (B/A), Silicon ratio (G), Silica/Alumina (S/A), Iron/Calcium (I/C), Carbon/Hydrogen (C/H), and Fixed Carbon/Volatile matter (FC/V) showed weak–medium-strong for the Ankpa coals and strong for Maiganga coals.