Building Technology

Permanent URI for this collectionhttp://197.211.34.35:4000/handle/123456789/135

Building Technology

Browse

Search Results

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Strength characteristics of modified black clay subgrade stabilized with cement kiln dust
    (2018) Jimoh I. O.; Amadi A. A; OGUNBODE, Ezekiel Babatunde
    This paper presents the results of a laboratory study in which the strength properties of black cotton soil (BC soil) subgrade modified with quarry fines (QF) were stabilized with cement kiln dust (CKD). The experimental program included Atterberg limits, compaction and unconfined compression testing of BC soil treated with QF at a constant dosage of 10% stabilized with CKD for dosages in the range 0–16% on dry weight basis. Soil mixtures were compacted with British Standard Light energy, and specimens for unconfined compression testing were prepared at predetermined optimum moistures and cured for 28 days. Test results showed that the studied soil which classify as A-7-6 (20) group in American Association of State Highway and Transportation Officials classification system has liquid limit and plasticity index of approximately 85.0 and 50.5%, respectively, as well as a free swell of 65.0%. The application of QF together with the varying percentages of CKD lowered these parameters to values compatible with specification for subgrade layers prescribed by Nigerian General Specification for Roads and Bridges. While the addition of QF caused an increase in the maximum dry unit weight of the soil, the introduction of CKD resulted in the reduction of the maximum dry unit weight of soil mixtures. On the other hand, optimum moisture contents increased slightly following the treatments. Furthermore, both the unconfined compressive strength (UCS) and the stiffness moduli (initial tangent, Ei, and secant, Esec, evaluated from the experimental stress–strain responses) of soil mixtures increased significantly as a consequence of the joint effects of quarry fines and CKD treatment producing soil mixtures with desired values for performance in road pavement subgrades.
  • No Thumbnail Available
    Item
    Effect of Age on the Structural Strength of Timbers Commonly Used in Nigeria
    (Environmental Technology and Science Journal, 2024) OJO Segun Olaniyi; OGUNBODE Ezekiel Babatunde; MAKUN Christopher Sunday; EKEKEZIE C. U.; ABDUL Aliyu
    Timber is a material used for structural purposes in construction. Hence, the knowledge of properties of timber especially strength and factor affecting the strength of timber is very important. Age of timber is one major factor affecting timber strength and timber was usually fetched without knowledge of whether the timber is matured to meet the structural strength required. Therefore, this research tends to evalutate the effect of age on the strength of some selected timber species so that forester and users likewise could be guided on when to deforest. In this study, timbers studied were Universitas Orientalis Kentuckiensis (Eku), Entandrophragma cylindricum (Sapele) and Gmelina Arborea (Melina). The age of timber was determined by counting the number of annual growth rings, which is the combination of early wood and late wood and samples of different ages of timber, were obtained by personal visit to forest where they were fetched freshly. The samples obtained were machined and trimmed to standard sizes according to BS 5268 pt2 2003. The compressive strength was done using a timber size of 20mm X 20mm X 60mm, 20mm X 20mm X 300mm for determination of the bending strength and shear was performed using 20mm X 20mm X 20mm timbers (all in three replicate). The maximum compressive strength values were 49.31kN/m2 (at 45years), 45.89kN/m2 (at 60years) and 11.30kN/m2 (at 25years) for Eku, Sapele and Melina while the maximum bending strength were 187.55kN/m2 (at 35years), 278.79kN/m2 (at 70years) and 176.36kN/m2 (at 20years) and shear strength were 10.05kN/m2 (at 50years), 9.22kN/m2 (at 70years) and 10.91kN/m2 (at 25years) for the for the three samples. It was concluded that age of timber affects the strength of timber.
  • No Thumbnail Available
    Item
    Effect of Addition of Calcium Nitrate on Selected Properties of Concrete Containing Volcanic Ash
    (Leonardo Electronic Journal of Practices and Technologies, 2011) OGUNBODE, Ezekiel Babatunde; HASSAN Ibrahim Ogiri
    Abstract In this work, the effect of addition of Calcium Nitrate on selected properties of concrete containing Volcanic ash as partial replacement for ordinary Portland cement by weight was investigated .The study carried out used 10% volcanic ash as partial replacement and an admixture, Ca(NO3)2 Was added to improve the strength of the resulting concrete at 2%, 4%, 6% 8% and 10% respectively. The result of setting time showed a decrease in both initial and final setting time of the mixture as the Ca(NO3)2 Content was increased. The result of chemical analysis of volcanic ash showed an increase in calcium oxide (CaO) content when calcium Nitrate Ca(NO3)2 was added from 11.67% to 33.68%. Cubes were cast and cured in water for 7, 14, 21, and 28 days .The resulting Strength at 28 days hydration period shows a strength increase as the percentage of Ca(NO3)2 was increased to 10% .