Civil & Environmental Engineering- Scholarly Publications

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Browsing Civil & Environmental Engineering- Scholarly Publications by Author "Adedokun S.I"

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    Open Access
    Assessment of Steel Slag as Replacement for Coarse Aggregate in Concrete: A Review
    (Faculty Engineering Hunedoara, 2018) Adedokun S.I; Anifowose M.A; Odeyemi S.O
    This study presents a review on the utilization of steel slag as replacement for coarse aggregate in concrete. Merits and demerits of steel slag in concrete as well as its physical properties and chemical compositions of steel slag are also presented. It has been reported that it is economical to use steel slag, as the costs of steel slag are just about 50% of that of conventional aggregates. However, the optimum replacement of coarse aggregate with steel slag that gives better mechanical properties (compressive strength, tensile strength and flexural strength) than conventional concrete is found to be between 30 and 60%. In South Western part of Nigeria, there are numbers of steel/iron producing company with large deposits of steel slag. Therefore, there is need for the utilization of this by-product (steel slag) in concrete production in Nigeria as cost of natural aggregates (fine and coarse aggregate) is becoming higher.
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    Open Access
    THE COMBINED EFFECTS OF SOIL, WATER AND SURCHARGE LOADS ON THE STRUCTURAL BEHAVIOURS OF CANTILEVER RETAINING WALL
    (Faculty of Engineering and Technology, Ogbomoso, Nigeria, 2013) Adedokun S.I; Oluremi J.R.
    Retaining walls are engineering structures constructed to resist lateral forces imposed by soil movement and water pressure; they are used as protection against the erosive forces of water and as a method of slope stabilization along highways, railroads and construction sites. This Study modeled the combined effects of soil, Surcharge loads and Hydrostatic pressure on the structural behaviours of cantilever retaining wall under varying geometric conditions. The limit state requirements for overturning, sliding and bearing pressure were studied under different geometric properties. The use of computer programming (Java) was employed for quick analyses of the conditions. This research therefore minimized the stress associated with the iterative process of design and analyses of these structures. The deductions gave range of satisfactory dimensions with respect to the height of the wall for the preliminary dimensioning state of design. This study also answered the remained unanswered question of the effects of an increasing load being supported by retaining wall. The results revealed that Cantilever retaining wall will perform satisfactorily based on the factors of safety of 1.5 and 2.0 as against sliding and overturning respectively if soil is ignored in front of the wall with following values of Base width: For wall supporting full submerged soil, the Base width, B  (1.25  0.005q) ; wall supporting submerge soil up to 0.6 of its Height, Base width, B  (0.881 0.00805q) and for wall with submerge soil up to 0.2 of wall height, Base width, B  (0.7093  0.0091) . Results also showed that safety factors against sliding and overturning increase at a decreasing rate with constant decrease in water level. This gives an indication that water level greatly affects the stability of the retaining wall, that is, the higher the water level the greater the sliding and overturning effects. Results also revealed that sliding safety factor increases constantly with Base width while factor of safety against overturning increases at an increasing rate. This also shows the severity of sliding as against overturning. Both safety factors also increase at a decreasing rate with Wall height giving an indication that the stability of cantilever retaining wall increases with its Height under the same load. For an increasing surcharge values, sliding safety factor decreases constantly while overturning decreases at a decreasing rate. This also explains why overturning is less critical as compared to sliding effect
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    Open Access
    Effect of Cement Kiln Dust on the Geotechnical Properties of Ede Clay, LAUTECH Journal of Civil and Environmental Studies
    (Department of Civil Engineering, LAUTECH, Ogbomoso, 2018) Adedokun S.I; Oluremi J.R.; Adekilekun N.; Adeola V.
    This paper investigated the effect of cement kiln dust (CKD) on the geotechnical properties of clay. Soil sample was collected from clay deposit at Ede North Local Government Area, Osun State, which lies within the geographical coordinates of 7N and 4E, was treated with up to 10% CKD. Sieve analysis, specific gravity, consistency limits, compaction (British Standard Light, BSL and West African Standard, WAS) and California Bearing Ratio (CBR) tests were carried out on both treated and untreated soil samples. Results showed that Ede clay is an A-7- 6 soil. Specific gravity increased from 2.61 to 2.91 with increase in CKD from 0 to 10%, maximum dry density (MDD) of the natural soil sample increased from 1.72 and 1.76 g/m’ to 1.84 and 1.85 g/m’ at 8% CKD for BSL and WAS, respectively. The unsoaked CBR of the specimen increased from 17 to 35% for 0-10% addition of CKD, and a similar trend was observed for the 24 hours soaked CBR values. This study indicated that CKD, though regarded as waste material, can be used to improve the geotechnical properties of Ede clay.
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    Open Access
    Effect of marble dust and steel slag on consistency limits and compaction characteristics of lateritic soil
    (IOP Publishing, 2019) Adedokun S.I; Ganiyu A.A.; Adedokun M.A
    Engineers are faced with the problems of providing very suitable materials for highway and other foundations construction. Lateritic soils are highly weathered indigenous soil available in large quantities but generally need improvements to adequately satisfy the required construction purposes. This research investigates the influence of steel slag and marble dust addition on some geotechnical properties of lateritic soil. The results revealed that the soil is well graded based on particle size distribution and is classified as A-2-5 under AASHTO system. With progressive increase in each stabiliser, both the liquid limit, plastic limit and plasticity index exhibit fluctuating patterns. In addition, both marble dust and steel slag increased the maximum dry density with increasing proportions in the soil sample but exhibit irregular patterns for optimum moisture content. This research provides an insight to the quality of lateritic soils obtainable in the study area, and the level of improvements required before they are suitable for road construction.
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    Open Access
    Effect of support characteristics on the earth pressure in a jointed rock mass
    (NRC Research Press, 2015) Son M; Adedokun S.I
    This study examines the magnitude and distribution of earth pressures against a support system in a jointed rock mass according to the support characteristics (strut stiffness and spacing), different rock types, and joint conditions (joint shear strength and joint inclination angle). A series of numerical parametric analyses were performed after verifying the numerical approach through a physical model test. These analyses were based on the discrete element method, which can take into account the joint characteristics of the rock strata and the interactions between the ground and the retaining structure. The results were compared with Peck’s earth pressure for soil ground, which showed that the magnitude and distribution of earth pressure are strongly affected by the support characteristics, rock types, and joint conditions, and that the earth pressure in the rock stratum can be significantly different from that in the soil ground. The results suggest that the support characteristics, including the rock types and joint conditions, are important factors affecting the earth pressure, and should be considered for the safe and economic design and construction of retaining structures in a jointed rock mass.
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    Open Access
    Optimal Replacement of Granite Modified with Ife Iron and Steel Slag on Strength Properties of Concrete
    (Trans Tech Publications, 2022) Adedokun S.I; Anifowose M.A
    Steel is produced from iron ore and purification of metal scrap, leading to manufacture of hundreds of tonnes of steel slag each year. This study investigated the optimum replacement of granite with Ife Iron and Steel Nigeria Limited (ISN) slag that produce maximum Compressive Strength (CS), Split Tensile Strength (STS) and Flexural Strength (FS) of concrete using Response Surface Methodology (RSM) from Design Expert Version 7.0. The outcome of the study showed that the optimum replacement of granite with ISN was 28.85% ISN at 0.47 W/C.
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    Open Access
    A review of the stabilization of lateritic soils with some agricultural waste products
    (Faculty Engineering Hunedoara, 2019) Adedokun S.I; Oluremi J.R.
    An attempt to reduce the amount of environmental wastes and the high cost of conventional stabilizers has led to continuous studies on the economic utilization of ash from agro-wastes for improving the engineering properties of soil. This paper therefore reviewed the impacts of some of these waste products to establish their effectiveness in improving geotechnical properties of lateritic soils. The wastes considered include saw dust ash (SDA), coconut husk ash (CHA), millet husk ash (MHA), corn cob ash (CCA), rice husk ash (RHA), bagasse ash (BA) and locust bean pod ash (LPBA). It was established that these ashes are good pozzolanic materials having satisfied the required standards. Also, increase in ash contents led to a significant decrease in the liquid limit, plasticity index, swelling index and shrinkage limit of soils. The maximum dry density of soil increased from 0 to 4% substitutions of SDA, CHA and CCA while it decreased with the addition of ashes from other wastes. CBR and UCS generally increased with increasing amount of the stabilizers whereas soil permeability and swell potential decreased as the ash content increased. Ash produced from these wastes can be used to improve the geotechnical properties of soil, to synthesize a stable soil mix, suitable for highway construction purposes