Browsing by Author "Chibuzor Onyelowe, Kennedy"
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Item Capillary rise, suction (absorption) and the strength development of HBM treated with QD base Geopolymer(International Journal of Pavement Research and Technology, 2018) Bui Van, Duc; Chibuzor Onyelowe, Kennedy; Nguyen, Manh VanTest soil sample was investigated and characterized under the laboratory conditions with the preliminary tests. It was classified as A-2-6 group soil according to the AASHTO classification method. It was also classified according to USCS as poorly graded (GP) with high clay content (CH). It was also classified as highly plastic with plasticity index above 17% and expansive. The soil sample was further treated with synthesized Quarry Dust (QD) base Geopolymer cement (GPC) at room temperature and the effect of the varying proportions of the GPC added in the proportions of 2.5, 5, 7.5, 10, 12.5, 15, 17.5, 20, 22.5, 25, 27.5, 30, 32.5, 35, 37.5 and 40% by weight of solid on the cemented and non-cemented test soils under varying curing time on the soil capillary rise, suction and strength development parameters (UCS, CBR and MRD) were investigated. The results obtained showed a consistent reduction in capillary rise and suction with increased proportion of QD base GPC and an increase in these properties with increased curing time. But cemented soil showed a slight higher reduction in capillary rise and suction than the non-cemented soil, but at 15% QDbGPC all the trials have capillary rise below 25%. The strength development consistently improved with increased proportion of QDbGPC, that at 12.5% GPC, the trials achieved CBR above 30%, a minimum required for a material to be used as base course material and reduced with prolonged curing time due to loss of strength on prolonged water absorption. Portland cement has high shrinkage, and less capillary and absorption tendencies, though it showed lesser values of capillary rise and suction but the difference between cemented and non-cemented soils is too small that QD base GPC can totally replace OPC because of the construction properties it exhibits. It also shows that QD base GPC beyond 40% by weight will keep improving the strength of treated soils and achieve higher compressive strengths.Item Effect of micro sized quarry dust particle on the compaction and strength properties of cement stabilized lateritic soil(Cleaner Materials, 2021) Kufre Etim, Roland; Ufot Ekpo, David; Attah, Imoh Christopher; Chibuzor Onyelowe, KennedyLaboratory investigation on the effect of micro sized quarry dust on engineering behaviour of cement stabilized lateritic soil was carried out. The specific concentration was on the effective way of curtailing, managing and disposing solid wastes generated from quarry activities by incorporating them as admixture in cement amelioration protocol of weak lateritic soil bound for sustainable subgrade material. In airfield, embankment, railways, pavement foundation structures, special attention/consideration/interest is continually laid on how moisture percolation affect the bearing capacity or strength of the subgrade layer. The quarry dust of 0 to 10 % was admixed with cement of 0 to 8 %, both in step increment of 2% by dry weight of the soil forming a combination matrix of twenty‐five test specimens in an amelioration protocol. The test results show that quarry dust admixture steadily improved the plasticity index of cement stabilized soil through the reduction in plasticity index. The maximum dry density in most part of the test, improved with increase in percentage stabilizers blend for the individual corresponding optimum moisture content of the treated soil. The mechanical properties (California bearing ratio and unconfined compressive strength) of cemented lateritic soil increased significantly with increase in the micro sized quarry dust stabilizer. The resistance to loss in strength showed that more than 80 % durability values was recorded. The SEM/EDS analysis of the optimally stabilized specimen in contrast to untreated soil established the development of calcite as C‐S‐H and C‐(A)‐S‐H. The formation of C‐S‐H and C‐(A)‐ S‐H which was also confirmed through the FTIR and XRD test was responsible for strength development.Item Experimental assessment of subgrade stiffness of lateritic soils treated with crushed waste plastics and ceramics for pavement foundation(International Journal of Low-Carbon Technologies, 2019) Chibuzor Onyelowe, Kennedy; Bui Van, Duc; Nguyen Van, Manh; Ezugwu, Charles; Amhadi, Talal; Sosa, Felix; Wu, Wei; Ta Duc, Thinh; Orji, Francis; Alaneme, GeorgeThe assessment of subgrade stiffness of four test soils treated with crushed waste ceramics (CWC) and crushed waste plastics (CWP) has been experimented on under laboratory conditions. There have been recorded failures of pavements resulting from inadequate subgrade formations and the use of weak and expansive soils as subgrade materials. The changes in the behavior of these foundation materials affect the performance and overall behavior of the entire pavement or foundation structure. The aim of this work was to assess the behavior of test soils commonly used as subgrade materials and treat same with selected solid waste based geomaterials to enhance their ability to withstand dynamic and cyclic loads. The selected solid waste based geomaterials were crushed waste ceramic and crushed waste plastics. The test materials including the soils were tested for characterization procedure. The preliminary test results showed that the test soils were classified as A-2-7, A-2-6, A-7 and A-7-5, respectively according to AASHTO classification system and poorly graded soils according to USCS. They were also classified as highly plastic soils and expansive with plasticity indexes of above 17%. The oxide composition test on the CWC and CWP shows that the materials possess pozzolanic properties with high aluminosilicates. The test soils were treated with these geomaterials in the proportion of 10% to 120% by weight. The treatment protocol showed that the CBR, resilient modulus, and r-value improved consistently with increased CWC and CWP. Lateral deformation observed from the modified triaxial compression also reduced consistently with increased proportions of CWC and CWP. It is novel to have achieved improved California bearing ratio characteristics, resilient modulus, resistance value and lateral deformation properties of the test soils with a solid waste based geomaterial. It is also promising that beyond the proportion utilized in the laboratory, the CWC and CWP treated soils will resist both axial and lateral deformation or failure when compacted to the maximum dry density and optimum moisture.Item Nanosized palm bunch ash (NPBA) stabilisation of lateritic soil for construction purposes(International Journal of Geotechnical Engineering, 2017) Chibuzor Onyelowe, KennedyThe stabilisation potential of Nanosized palm bunch ash (NPBA) was investigated. This investigation was aimed at assessing the effect of NPBA on the stabilisation of Umuntu Olokoro lateritic soil. The soil was studied under varying proportions of the NPBA mixed at 0% (control), 3, 6, 9, 12 and 15% by weight of the stabilised soil. The soil properties’ tests; soil classification or grading test, specific gravity, compaction test, consistency limits tests, unconfined compressive strength (UCS) test, California bearing ration (CBR) test and UV/VIS spectrophotometric characterisation were conducted. The UV–VIS test was conducted on the ash and the lateritic soil to determine their absorbance, wavelength and average particle size. The results of the preliminary tests showed that the soil was classified as A-2-7 soil on AASHTO classification with group index of “0” a Matlab program run on the sample also predicted that the soil is made of silty or clayey gravel and sand and that the general rating as a sub-grade material was “GOOD”. The average particle size of the ash by Debye Scherrer’s method was 11.358 nm and the maximum absorbance was 1.120 nm at the wavelength of 650 nm. The optimum moisture content OMC increased at 12 and 15% by weight of NPBA compared to the 0% NPBA proportion, which gave 13%. The Maximum Dry Density (MDD) decreased from 1.84 to 1.72 kN/m2 followed by a consistent increase in the value as higher percentages of admixtures were added. It was observed that the 6% NPBA gave the highest value of MDD of 1.93 g/cm3 followed by 9% NPBA of 1.84 g/cm3. The California Bearing Ratio (CBR) test results showed high and low values of CBR with 9% NPBA, which gave the highest (CBR) value of 30%. 12% addition of the admixture (Nanosized Palm Bunch Ash) by weight gave the highest unconfined compressive strength value of 399.46 kN/m2 at 28 days curing time. The least percentage NPBA (3%) gave the lowest UCS value of 192.9746 kN/m2. From the general results recorded, it is important to note that using lower percentages of NPBA as an admixture in treating lateritic soil will yield considerably, poor results. If NPBA should be used, it should be in higher percentages. However, 12% NPBA by weight of stabilised soil gave the best results and is preferred for use to stabilise lateritic soils for construction purposes.Item Performance of lateritic soil stabilized with combination of bone and palm bunch ash for sustainable building applications(Cogent Engineering, 2021) Ijeoma Obianyo, Ifeyinwa; Aboubakar Mahamat, Assia; Nneka Anosike-Francis, Esther; Tido Tiwa, Stanislas; Geng, Yang; Chibuzor Onyelowe, Kennedy; Odusanya, Shola; Peter Onwualu, Azikiwe; Soboyejo, Alfred B. O.Affordable building for mass housing is the panacea for the housing deficit affecting the increasing population of the African continent especially Nigeria. Harnessing the abundant local building materials present in Africa is key for making adequate houses affordable for the populace. Lateritic soil is an earth-based building material (Jayasinghe & Kamaladasa, 2006) that is among the topmost available local building materials abundantly available in Nigeria and other tropical countries (Oluremi et al., 2012). Earth-based building materials are cheaper than cement and eco-friendly (Alam et al., 2015). Earth-based building materials are cheaper than cement because of the high embodied energy used for cement production. Unlike the cement, earth-based materials production do not release greenhouse gases to the environment and this makes them non-toxic and eco-friendly. The lateritic soil is composed mainly of quartz, iron–magnesium–manganese (amphibole group), and kaolinite (Egenti & Khatib, 2016). Soils having a ratio of silica to sesquioxide [SiO2/(Fe2O3 + Al2 O3)] which are less than 1.33 are classified as laterites whereas the ones between 1.33 and 2.00 are classified as lateritic soil, and those above 2.00 are classified as non-lateritic soils (Nnochiri & Adetayo, 2019). Lateritic soil can easily be recycled and that makes it a sustainable building material (Onakunle et al., 2020). However, due to their lower compressive strength, water absorption, and dimensional stability compared to cementitious materials, lateritic blocks are considered as non-durable building materials. A wide range of chemical stabilization techniques such as the use of cement, lime, agro-waste ash, and plastic waste has been investigated to improve the physical, chemical, and mechanical properties of earth-based materials (Apampa, 2017; Fadele & Ata, 2018; Hamada et al., 2020; Jamil et al., 2013; Moraes et al., 2019; Onyelowe, 2017a, 2017b; Rimal et al., 2019). The properties improved include compressive strength, water absorption, durability, ultrasonic pulse velocity, dry shrinkage, flexural strength, splitting tensile strength and workability.Item Predicting strength behaviour of stabilized lateritic soil–ash matrix using regression model for hydraulically bound materials purposes(International Journal of Pavement Research and Technology, 2018) Chibuzor Onyelowe, Kennedy; Bui Van, DucThe multiple regression relationship models were applied on the strength properties of the treated lateritic soil to deduce models. These models were verified to be valid to be applied under different test conditions to determine the dependent variables of the compaction, Atterberg, California bearing ratio and unconfined compression tests. The results showed that the behaviour of the variables under laboratory condition was in tandem with the regression model results. This is a strong indication that the regression model can be applied in the field of soil stabilization in a statistical engineering application to predict consistent values to determine treatment variations.Item Recycling and reuse of solid wastes; a hub for ecofriendly, ecoefficient and sustainable soil, concrete, wastewater and pavement reengineering(International Journal of Low-Carbon Technologies, 2019) Chibuzor Onyelowe, Kennedy; Bui Van, Duc; Ubachukwu, Obiekwe; Ezugwu, Charles; Salahudeen, Bunyamin; Nguyen Van, Manh; Ikeagwuani, Chijioke; Amhadi, Talal; Sosa, FelixEcofriendly, ecoefficient and sustainable civil engineering work has been research with emphasis on adapting the byproducts of solid waste recycling and reuse to achieving infrastructural activities with low or zero carbon emission. The direction combustion model, the solid waste incinerator caustic soda oxides of carbon entrapment model (SWI-NaOH-OCEM) developed by this research has achieved a zero carbon release. This research adopted the literature search method to put together research results of previous works relevant to the aim of this present work. It has been shown that CO and CO2 emissions can be contained during the derivation of alternative or supplementary cementing materials used in the replacement of ordinary Portland cement in civil engineering works. In the overall assessment of the present review work has left the environment free of the hazards of CO and CO2 emissions. It was shown that these supplementary cementing materials derived from solid wastes improve the engineering properties of treated soft clay and expansive soils, concrete, and asphalt. Bio-peels, another form solid waste has been established as a good detoxificant used in treating wastewater. It has been shown that solid waste recycling and reuse is a hub to achieving ecofriendly, ecoefficient and sustainable infrastructural development on the global scale.Item Review on the role of solid waste materials in soft soils reengineering(Materials Science for Energy Technologies, 2019) Chibuzor Onyelowe, KennedyEnvironmental degradation resulting from CO2 emission and the constant collapse of foundation of facilities more especially pavements in Nigeria has posed serious threat to the overall economic growth of the nation. More so, Nigeria lacks an efficient solid waste disposal mechanism and policies hence indiscriminate disposal of waste poses yet another threat. This review work has brought to bear the interrelations between these problems. Geotechnical engineering in this paper serves as a locus to bring these threatening environmental conditions into workable and beneficial stream. First this paper tries to outline selected solid waste materials from which geomaterials utilized in the stabilization of soft soils are derived by direct combustion or crushing. Secondly, the utilization of these derivatives, which serve as alternative cement in stabilization of soft soils presents construction methods devoid of CO2 emission because these materials are eco-friendly. Lastly, by adapting the use of these materials in soil strength improvement, the solid wastes find their way out through the recycling process and eventual usage as geomaterials sources. Research results have shown that these materials derived from solid waste because of their high aluminosilicate content improved the mechanical and strength properties of soils.Item Swelling potential, shrinkage and durability of cemented and uncemented lateritic soils treated with CWC base geopolymer(International Journal of Geotechnical Engineering, 2018) Chibuzor Onyelowe, Kennedy; Bui Van, Duc; Nguyen Van, ManhThe swelling potential, shrinkage limits, strength development and durability of crushed waste ceramic base geopolymer cement (CWCbGPC) treated test soils A, B and C have been studied under the laboratory conditions. The test soil samples were preliminarily investigated and characterized under the laboratory conditions. Soils A, B and C were classified as A-2-7, A-2-6 and A-7, respectively, according to the AASHTO classification method. They were also classified according to USCS as poorly graded. Additionally, soils A and C were observed as having higher clay content than soil B. They were also classified as highly plastic with plasticity index above 17% and expansive. The free swell index and shrinkage tests showed that they had high potential for swelling and shrinkage. The treated soils show significant improvement in swelling, shrinkage, strength development and durability with CWCbGPC while the cemented soils failed in terms of shrinkage and durability, which proved that Portland cements have high potential for shrinkage with soil blends. The results of the laboratory study have shown that CWCbGPC and other geopolymer cements can totally replace Portland cements in civil engineering works more especially in the construction of hydraulically bound structures.Item Understanding the impacts of binary additives on the mechanical and morphological response of ameliorated soil for road infrastructures(Journal of King Saud University-Engineering Sciences, 2021) Christopher Attah, Imoh; Kufre Etim, Roland; Ufot Ekpo, David; Chibuzor Onyelowe, KennedyIn an attempt to promote a cleaner environment, the deployment of waste materials in soil amendment protocols have been a major concern for civil engineers. Recent discoveries in the study of soil mechanics have revealed the pozzolanic tendencies demonstrated by these waste materials, which are beneficial in the development of road infrastructure. This has necessitated the need for this research to document the impacts of exploring the usage of combined solid waste derivatives in ameliorating the geotechnical parameters of deficient soil. The current stabilization exercise was geared towards the improvement of the mechanical properties of soil and surpassing the detrimental tendencies especially caused by seasonal variations. Moving forward, the microstructural response of the unaltered and additive ameliorated soil was investigated via qualitative means such as scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The additives including cement kiln dust (CKD) and rice husk ash (RHA), were added by air-dried weight of the soil and compacted based on the standards of British Standard Light (BSL), West African Standard (WAS) and British Standard Heavy (BSH). With regard to the compaction exercise, incorporation of these additive materials into the soil facilitated a gradual increase in the maximum dry density (MDDs) followed by a decrease in the optimum moisture contents (OMCs). In view of these research findings, soil treatment studies facilitated a substantial upsurge in the strength (California bearing ratio (CBR) and unconfined compressive strength (UCS)) values of the ameliorated soil, in agreement with the requirements of Nigeria general specification for all compactive efforts. Finally, the usefulness and efficacy of combining these wastes in deficient soil treatment were validated qualitatively via the SEM and FTIR strategies. The results of the SEM analysis revealed some disparities between the unaltered and altered soil specimens, providing insights into the direction of calcite formation in the additive-treated soil.