Browsing by Author "Olutaiwo, A. O."

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    Efficiency of Cow Bone Ash (CBA) In Mitigating Alkali Silica Reaction (ASR) Based On Accelerated Mortar Bar Test (AMBT) In Concrete Pavements
    (Conference: Faculty of Engineering International Conference (FEIC_2019), 2019-10) Adanikin, Ariyo; Falade, F. A.; Olutaiwo, A. O.
    Nigerian roads which are predominantly flexible pavements are in a deteriorated state and requires frequent maintenance before the expiration of their design life. Rigid/Concrete pavements serves as a better alternative to flexible pavements on the long term considering their ability to contain higher traffic load, constructed over a weak subgrade, requiring little maintenance and many much benefits. Concrete pavements however are susceptible to Alkali Silica Reaction (ASR) which compromises the strength and morphological properties of the pavement. This has necessitated studies on the use of supplementary cementitious materials (SCMs) to reduce the effect of ASR and enhance the properties of the concrete pavement. The efficiency of SCMs such as Cow Bone Ash (CBA) to partially replace cement and mitigate the effect of ASR in concrete is researched in this study. This will help reduce the menace of greenhouse gas emission that results from the production of cement required for concrete pavement construction. Concrete bars of known dimensions were constructed with partial replacement of cement by CBA (0%-30%). The expansion of the concrete bars was measured on the 7th, 14th and 28th day of immersion in 1M NaOH. The concrete bars expansion values are then compared to VicRoads 610 and ASTM C1260 standards to determine the concrete reactivity classification. The study revealed that at above 15% CBA replacement levels, cow bone ash is efficient for use in rigid pavements for mitigating the effects of Alkali Silica Reaction. The regression analysis of concrete cubes expansion against percentage of CBA replacement indicates a high level of relationship between both variables. This indicates that the higher the level of CBA addition, the lower the level of concrete expansion and lower level of ASR attack in the Portland cement/rigid pavement. Recommendations on how ASR can be mitigated in new and existing structures are highlighted
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    Evaluating the Quality Assurance and Control of Hot-Mix Asphalt from Selected Plants in South West, Nigeria
    (2020-06-25) Olutaiwo, A. O.; Adanikin, Ariyo
    Roads are essential necessity of every nation and it is possible that even with proper designs, the roads might not be constructed to the design standard due to poor quality assurance and control resulting in poor pavement quality. This study presents experimental results carried out on various hot - mix asphalt (HMA) samples obtained across different Asphalt plants in South West Nigeria. This was done to determine the extent to which the HMA used in the construction and rehabilitation of Nigerian roads affect their service life. Six samples of the asphalt binder (bitumen) were obtained from each plant over a period of six months and tested. The tested properties were assessed based on the level of conformance with the specifications and requirements from the FMWH General Specification (Roads and Bridges). The results revealed that HMA from plant B had a specific gravity of 1.01, penetration of 65.00 mm, softening point of 53 oC, flash point of 237.00 oC, peak Marshall Stability of 18.25 kN, flow of 3.87 mm and voids in total mixture peak value of 5.08 %. HMA from plant E had a specific gravity of 1.03, penetration of 65.00 mm, softening point of 51 oC, flash point of 239.00 oC, peak marshall stability of 18.26 kN, flow of 3.67 mm and voids in total mixture peak value of 4.99 % and these were adjudged the best in conformance with the FMWH specifications. Adequate monitoring of HMA quality for either binder or wearing courses by carrying out quality control and assurance tests is thereby recommended as it affects pavement durability and performance
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    Investigation of the effect of alkali silica reaction (ASR) on properties of concrete pavement admixed with cow bone ash (CBA) by electrical resistivity test
    (1st International Conference on Sustainable Infrastructural Development, 2019) Adanikin, Ariyo; Falade, F.; Olutaiwo, A. O.; Faleye, E. T.; Ajayi, A. J.
    The use of concrete in road pavements construction in view of its durability and cost effectiveness over time have gained momentum. Cement concrete pavements however suffer deterioration due to Alkali-Silica Reaction (ASR). This study therefore investigates the use of Cow Bone Ash (CBA) in mitigating the effect of ASR using electrical resistivity test (schlumberger array probe method). The results are then compared with American Society for Testing and Materials (ASTM) standards and relevant literatures. The result of the study showed that the average resistivity at 0%, 5%, 10%, 15%, 20% and 30% CBA replacement are 298.87 Ωm, 306.23 Ωm, 215.02 Ωm, 489.31 Ωm, 382.34 Ωm and 272.53 Ωm respectively. This indicates that the peak resistivity is obtained at 15% CBA replacement which is the optimal replacement level for ASR inhibition in the concrete. The result also shows that the concrete samples are corrosion free with the least resistivity value on the 7th day at 30% CBA addition (163.03 Ωm) and the maximum value at 20% CBA addition on the 56th Day (1069.54 Ωm). The study concluded that ASR and reinforcement corrosion can be effectively controlled between 15% and 20% cement replacement by CBA in concrete/rigid pavements