NRU :: Browsing by Author "Bui Van, Duc"

Browsing by Author "Bui Van, Duc"

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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 Van
Test 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.
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, George
The 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.
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.
Pozzolanic Reaction in Clayey Soils for Stabilization Purposes: A Classical Overview of Sustainable Transport Geotechnics
(Advances in Materials Science and Engineering, 2021) Onyelowe, Kennedy C.; Onyia, Michael E.; Bui Van, Duc; Baykara, Haci; Ugwu, Hyginus U.
Problematic soil stabilization processes involve the application of binders to improve the engineering properties of the soil. /is is done to change the undesirable properties of these soils to meet basic design standards. However, very little attention has been given to the reactive phase of soil stabilization. /is phase is the most important in every stabilization protocol because it embodies the reactions that lead to the bonding of the dispersed particles of clayey soil. Hence, this reactive phase is reviewed. When clayey soils which make up the greatest fraction of expansive soil come in contact with moisture, they experience volume changes due to adsorbed moisture that forms films of double diffused layer on the particles. When this happens, the clayey particles disperse and float, increasing the pore spaces or voids that exist in the soil mass. Stabilizations of these soils are conducted to close the gaps between the dispersed clayey soil particles. /is is achieved by mixing additives that will release calcium, aluminum, silicon, etc., in the presence of adsorbed moisture, and a hydration reaction occurs. /is is followed by the displacement reaction based on the metallic order in the electrochemical series. /is causes a calcination reaction, a process whereby calcium displaces the hydrogen ions of the dipole adsorbed moisture and displaces the sodium ion responsible for the swelling potential of clayey soils. /ese whole processes lead to a pozzolanic reaction, which finally forms calcium alumina-silica hydrate. /is formation is responsible for soil stabilization.
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, Duc
The 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.
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, Felix
Ecofriendly, 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.
Scheffe optimization of swelling, California bearing ratio, compressive strength, and durability potentials of quarry dust stabilized soft clay soil
(Materials Science for Energy Technologies, 2019) Onyelowe, Kennedy; Alaneme, George; Igboayaka, Clifford; Orji, Francis; Ugwuanyi, Henry; Bui Van, Duc; Nguyen Van, Manh
Scheffe’s second degree polynomial was used to formulate models for predicting the swelling potential, California bearing ratio, unconfined compressive strength and loss of strength on immersion durability of quarry dust treated soil. These models could predict the swelling potential, California bearing ratio, unconfined compressive strength and loss of strength on immersion durability of treated soil if the mix ratios are known and vice versa. The response predicted by the models are in good agreement with the corresponding experimentally observed results. The result of these tests shows the feasibility of using quarry dust in soil stabilization. The student t-test and the analysis of variance (ANOVA) test were used to check the adequacy of the models, and the models were found to be adequate at 95% confidence level. With the optimized equations, the properties’ design, behaviour, and performance of treated soft clay soil as a pavement subgrade material will be appropriated and monitored. This will be for any possible volume changes, shear failures, strength failures and durability failures when the material used as a hydraulically bound material is in contact with moisture beyond its optimum and subjected to dynamic load beyond its design value.
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.
Structural analysis of consolidation settlement behaviour of soil treated with alternative cementing materials for foundation purposes
(Environmental Technology & Innovation, 2018) Onyelowe, Kennedy; Bui Van, Duc
The structural analysis of the application of quarry dust (QD), crushed waste ceramics (CWC), palm bunch ash (PBA), crushed waste ceramics base geopolymer cement (CWCbGPC) and palm bunch ash base geopolymer cement (PBAbGPC) in the treatment of soil has been studied. The need to encourage the use of supplementary cementing materials in construction works is of great necessity. This is because of the further damage the emission of CO2 is causing and its contribution to global warming. Laboratory experiments have been adopted to investigate the behaviour of test soil on the addition of admixtures. After the preliminary study, it was shown that the test soil was an A-7 soil according to AASHTO classification system and poorly graded soil of high clay content (GP/CH) according to the USCS. The treatment protocol was used to study the consolidation settlement (CS) of the treated test soil and results showed that the CS reduced steadily at the varied addition of the cementing additives. A more remarkable improvement was recorded with the geopolymer cements (GPC). The results equally showed that the PBAbGPC was observed to be better than the CWCbGPC in the treatment protocol. The exercise not only achieved the ridding the environment of solid wastes but showed that these waste materials could be reclaimed and synthesized into alternative cementing materials to replace ordinary Portland cement and remove its attendant CO2 emission and the global warming effects from the atmosphere.
Swelling Potential of Clayey Soil Modified with Rice Husk Ash Activated by Calcination for Pavement Underlay by Plasticity Index Method (PIM)
(Advances in Materials Science and Engineering, 2021) Onyelowe, Kennedy C.; Onyia, Michael E.; Nguyen-Thi, Diu; Bui Van, Duc; Onukwugha, Eze; Baykara, Haci; Obianyo, Ifeoma. I.; Dao-Phuc, Lam; Ugwu, Hyginus U.
Volume change in expansive soils is a problem encountered in earth work around the world. ,is is prominent with hydraulically bound structures or foundations subjected to prolonged moisture exposure. ,is behavior of clayey used as subgrade, foundation, landfill, or backfill materials causes undesirable structural functionality and failures. To prevent this happening, clayey soils are studied for possible volume change potential and degree of expansion. Consequently, the problematic soils are stabilized. In this work, the stabilization of clayey highly expansive soil classified as A-7-6 soil and highly plastic with high clay content was conducted under laboratory conditions. ,e treatment exercise was experimented using quicklime-activated rice husk ash (QARHA), hydrated lime-activated rice husk ash (HARHA), and calcite-activated rice husk ash (CARHA) at the rates of 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, and 10%. Upon treatment with the three calcium compounds to produce three sets of treated experimental specimens, the plasticity index was observed and recorded and swelling potentials were evaluated using the plasticity index method (PIM). ,e results showed a consistent improvement on the properties of the treated soil with the addition of the different activated admixtures. While the utilization of CARHA and HARHA improved the clayey soil to medium expansive soil, the treated clayey soil substantially improved from highly expansive soil with a potential of 23.35% to less expansive with a final potential of 0.59% upon the addition of 10% QARHA. Finally, QARHA was adjudged as the best binding composite due to the highest rate of reduction recorded with its utilization.
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, Manh
The 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.
Triaxial and density behaviour of quarry dust based geopolymer cement treated expansive soil with crushed waste glasses for pavement foundation purposes
(International Journal of Pavement Research and Technology, 2019) Onyelowe, Kennedy; Igboayaka, Clifford; Orji, Francis; Ugwuanyi, Henry; Bui Van, Duc
The effect of quarry dust based geopolymer cement (QDbGPC) and crushed waste glasses (CWG) on the triaxial and density characteristics of expansive test soil was investigated under laboratory conditions. Quarry dust is a solid waste the management of which poses a big problem to construction and environmental experts. So also is the management of waste glasses. Then again, the use conventional cement poses everyday threat to the environment as its utilization releases huge amount of CO2 to the environment thereby causing increased global warming. However, the utilization of quarry dust in the synthesis of geopolymer cements which is an eco-friendly geomaterial and by extension its use in the soil treatment protocol is the aim of this work. The test soil was observed to be a poorly graded A-2-6 soil according to USCS and AASHTO classification systems respectively. The treatment exercise showed that the shear characteristics of the treated soil improved consistently. The poisson ratio, porosity and submerged density i mproved with increased additives. The stress-strain relationship improved to a very stiff consistency which satisfies the requirements for subgrade and subbase materials in pavement construction. Finally, the utilization of QDbGPC proved to be a good replacement for conventional cement in terms of environmental issues resulting from CO2 emission, resistant to moisture, heat, sulphate attacks, etc on hydraulically bound materials.
Valorization and sequestration of hydrogen gas from biomass combustion in solid waste incineration NaOH oxides of carbon entrapment model (SWI-NaOH-OCE Model)
(Materials Science for Energy Technologies, 2020) Onyelowe, Kennedy C.; A. Onyelowe, Deborah Favour; Bui Van, Duc; Ikpa, Chidozie; Salahudeen, Bunyamin; Eberemu, Adrian O.; Osinubi, Kolawole J.; Onukwugha, Eze; Odumade, Adegboyega O.; Chigbo, Ikechukwu C.; Amadi, Agapitus A.; Igboayaka, Ekene; Obimba-Wogu, Jesuborn; Saing, Zubair; Amhadi, Talal
The valorization of biomass-based solid wastes for both geotechnical engineering purposes and energy needs has been reviewed to achieve eco-friendly, eco-efficient and sustainable engineering and reengineering of civil engineering materials and structures. The objective of this work was to review the procedure developed by SWI-NaOH-OCE Model for the valorization of biomass through controlled direct combustion and the sequestration of hydrogen gas for energy needs. The incineration model gave a lead to the sequestration of emissions released during the direct combustion of biomass and the subsequent entrapment of oxides of carbon and the eventual release of abundant hydrogen gas in the entrapment jar. The generation of geomaterials ash for the purpose of soil stabilization, concrete and asphalt modification has encouraged greenhouse emissions but eventually the technology that has been put in place has made it possible to manage and extract these emissions for energy needs. The contribution from researchers has shown that hydrogen sequestration from other sources requires high amount of energy because of the lower energy states of the compounds undergoing thermal decomposition. But this work has presented a more efficient approach to release hydrogen gas, which can easily be extracted and stored to meet the energy needs of the future as fuel cell batteries to power vehicles, mobile devices, robotic systems, etc. More so, the development of MXene as an exfoliated two-dimensional nanosheets with permeability and filtration selectivity properties, which are connected to its chemical composition and structure used in hydrogen gas extraction and separation from its molecular combination, has presented an efficient procedure for the production and management of hydrogen gas for energy purposes.

Browsing by Author "Bui Van, Duc"

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