Browsing by Author "Ugorji, Benjamin"

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    Generalized Review on EVD and Constraints Simplex Method of Materials Properties Optimization for Civil Engineering
    (Civil Engineering Journal, 2019) Onyelowe, Kennedy; Alaneme, George; Bui Van, Duc; Nguyen Van, Manh; Ezugwu, Charles; Amhadi, Talal; Sosa, Felix; Orji, Francis; Ugorji, Benjamin
    Extreme vertex design (EVD) has been adapted to be used in the modeling of the behavior of mixture experiments in civil engineering. This method has been in use since the 1970s and has be prevalent in the field of medical science. Various other methods of design of experiments have been used in engineering but neither has EVD being used particularly in civil engineering. This review is presented to serve as a hub or guide for subsequent exercise where concrete production, asphalt production or modification, soils stabilization and concrete improvement or water treatment would be studied with the help EVD. Its ability to fix design points and centroids has been reviewed in this work. EVD operates with various algorithms and depends on the order or condition of problems to be solved. The XVERT algorithm working on Minitab and Design Expert platform was adopted in this review work because of its efficiency in handling quadratic model problems like the four cases reviewed in the present work. From the four special cases, it can be asserted that there is a confidence in the use of EVD to develop the constraints, design the experimental factor space, design the mix proportions, and validate the models resulting from these procedures after experimental specimens are tested to determine the responses.
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    Sorptivity, swelling, shrinkage, compression and durability of quarry dust treated soft soils for moisture bound pavement geotechnics
    (Journal of Materials Research and Technology, 2019) Onyelowea, Kennedy; Onyelowe, Kennedy; Bui Van, Duc; Eberemu, Adrian; Xuan, Man Nguyen; Salahudeen, Bunyamin; Ezugwu, Charles; Nguyen Van, Manh; Orji, Francis; Sosa, Felix; Ta Duc, Thinh; Amhadi, Talal; Ikpa, Chidozie; Ugorji, Benjamin
    The failure of pavement foundation materials as hydraulically bound materials is a worri-some condition facing pavement infrastructures in the developing world. Capillary action leads to swelling and shrinkage, compressive strength and durability problems, which result from sorptivity as a function of hydraulic exposure conditions. Pavement infrastructures a constantly interfaced with rise and fall of ground water level and capillary action hence a study on the sorptivity behaviour of quarry dust (QD) treated soft clay soils was carried out. Preliminary tests were conducted on the test materials for the purpose of charac-terization. The basic test results show that the test soils S1, S2 and S3 were classified asA-2-7, A-2-6 and A-7 soil groups respectively according to AASHTO classification system.Also, they were classified as poorly graded soils but test soils S1 and S2 were observed to be of high clay content (CH) according to USCS. The test soils were equally observed to be of highly plasticity and contains high free swell index properties, hence are expansive.