Civil Engineering

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Effects of charcoal production on maize yield, chemical properties and texture of soil
(Biology and Fertility of soils (Springer-Verlag), 2004-03) Oguntunde, Philip G.; Fosu, Matthias; Ajayi, Ayodele E.; Van de Giesen, Nick
The effects of charcoal production on soil textural and chemical properties were investigated in Ejura, Ghana. The aim was to study the effects of heating and charcoal residue on maize yield, soil texture and soil chemical properties. Composite samples were taken from the 0–10 cm layer of soil at charcoal-making sites and from adjacent fields (control). Twelve sites were randomly selected for the study across the range of the Kotokosu watershed. Maize was planted in four selected locations on charcoal site soils (CSS) and adjacent field soils (AFS) to assess the impact of charcoal production on crop yield. There was a significant increase in soil pH, base saturation, electrical conductivity, exchangeable Ca, Mg, K, Na and available P in the soil at the kiln sites as compared to the adjacent soils. A relative change of up to 329% was observed in K while organic C and total N decreased by 9.8% and 12.8%, respectively. Organic C and total N were highly correlated ( P <0.01) and both parameters significantly ( P <0.05) depended on clay minerals in the soils. Soil texture was also modified with a significantly higher sand content and lower clay fraction in the CSS. The grain and biomass yield of maize increased by 91% and 44%, respectively, on CSS as compared to AFS. Further research to ascertain the longterm effects of charcoal production on the soil environment and the fertility of tropical soils is needed. Keywords Charcoal production · Soil heating · Soil fertility · Maize yield · Ghana
Effects of charcoal production on soil physical properties in Ghana
(WILEY‐VCH Verlag, 2008-08) Oguntunde, Philip G.; Abiodun, Babatunde J.; Ajayi, Ayodele E.; Van De Giesen, Nick
Charcoal production, widespread in Ghana like in other W African countries, is a major driver of land-cover change. Effects of charcoal production on soil physical, including hydrological, properties, were studied in the forest–savannah transition zone of Ghana. Core and composite samples from 12 randomly selected sites across the width of Kotokosu watershed were taken from 0–10 cm layer at charcoal-site soils and adjacent field soils (control). These were used to determine saturated hydraulic conductivity (Ksat), bulk density, total porosity, soil texture, and color. Infiltration rates, surface albedo, and soil-surface temperature were also measured on both sites. The results showed that the saturated hydraulic conductivity of soils under charcoal kilns increased significantly (p < 0.01) from 6.1 ± 2.0 cm h–1 to 11.4 ± 5.0 cm h–1, resulting to a relative increase of 88%. Soil color became darkened under charcoal kilns with hue, value, and chroma decreasing by 8%, 20%, and 20%, respectively. Bulk density on charcoal-site soils reduced by 9% compared to adjacent field soils. Total porosity increased from 45.7% on adjacent field soils to 50.6% on earth kilns. Surface albedo reduced by 37% on charcoal-site soils while soil-surface temperature increased up to 4°C on average. Higher infiltration rates were measured on charcoal-site soils, which suggest a possible decrease in overland flow and less erosion on those kiln sites. Keywords: charcoal production / soil physical properties / Ksat / infiltration rates / reflection coefficient / watershed hydrology
Rainfall trends in Nigeria, 1901–2000
(Elsevier (Journal of Hydrology), 2011-12-09) Oguntunde, Philip G.; Abiodun, Babatunde J.; Lischeid, Gunnar
There is the need to evaluate changes in the spatial and temporal patterns of rainfall in order to improve water management strategies of a given region. In this study, standard tests are used to examine the existence of trend in annual and monthly rainfall of Nigeria over the last century. Rainfall variability index was estimated as standardized rainfall departure while autocorrelation spectral analysis is used to obtain the periodicities inherent therein. Rainfall spatial distribution was highly latitudinal dependent (r2 > 0.90) and had no clearly linear relations with the longitude. Rainfall variability index showed that 1950s was the wettest decade (+0.84) while 1980s was the driest (−1.19), with the two decades between 1970 and 1990 being drier than any other comparable period in the last century. Observed rainfall changes varied between −3.46 and +0.76 mm yr−2. About 90% of the entire landscape exhibited negative trends but only 22% showed significant changes at 5% level. There was a sharp difference between changes in rainfalls in 1931–1960 and 1961–1990 periods. Annual precipitation reduced by 7% between the two periods. While more than 90% of the landscape showed no significant rainfall change in the first period, about 57% of Nigeria showed a significant (P < 0.05) decrease in the second. The dominant peaks can be classified into four distinct rainfall cycles with periods 2–3, 5–7, 10–15 and 30 yr. These cycles may be associated with the stratospheric Quasi-Biennial Oscillation (QBO), the El-Nino Southern Oscillation (ENSO); the sunspot cycles and the Atlantic Multi-Decadal Oscillation (AMO) sea surface temperature, respectively.
Quality assessment of Sandcrete blocks in Ibadan – A review
(Epistemics in Science Engineering and Technology, 2013) Adeniji, Akintayo A.; Ganiyu, A. A.; Ajagbe, W. O.
Sandcrete blocks have been widely used for modern building construction in Nigeria; however cases of incessant building collapse are rampant. The usage of substandard sandcrete blocks is a contributing factor. This research was carried out to assess the engineering properties of sandcrete blocks produced in Ibadan and its environs. Two blocks each of size 450 x 225 x 225mm were purchased from selected block industries at eight sampled locations within the study area. Few units of blocks (450 x 225 x 225mm) conforming to the Nigerian Industrial Standard (NIS 87: 2007) were also produced to serve as control samples. The 28th day dry compressive strength test result obtained for the sampled blocks ranges between 0.39-2.34 N/mm2. For the control block samples, the average 28th day dry compressive strength of the three tested blocks was 3.02 N/mm2. Conclusively, it was observed that the sandcrete blocks produced in major parts of Ibadan were of low quality and substandard; while the control samples were of adequate strength.
SIMULATION AND MODELING OF A CARBURIZING PROCESS USING VARIABLES FOR EFFECTIVE PERFORMANCE IN SERVICE IN AISI 1032 STEEL
(The American Ceramic Society, 2015) Adegbola, Adekunle; Akeem, Ghazali; Alabi, Ismaila; Kareem, Mutiu
The mechanical properties of AISI 1032 steel samples carburized in Wood Charcoal and Snail Shell were investigated. The samples were modeled and simulated using Fick’s law and C++, in order to evaluate the performances of solid carburizing media on the mechanical properties of steels at different conditions. The results revealed that the case depth, tensile strength and hardness values of samples carburized with Wood Charcoal (WChl) are higher compared to those carburized with Snail Shell (SS) at 800 0C and 950 0C respectively. These were evidently substantiated with their micrographs as observed under DV-500 Version 10.2 Metallurgical Microscope with X500 magnification. The case-depth is directly proportional to the carburized temperature and time. It was concluded that Fick’s law is good at predicting the diffusion of carbon in steels.
Numerical Simulation of Temperature Distribution in A Tri-Cycle Engine Piston
(International Journal of Scientific & Engineering Research,, 2015-06) Alabi, Ismaila Olanrewaju; Adesina, Olaiya Kamorudeen; Olalekan, Kareem Mutiu
Pistons as one of the most complex components among all automotives and other industry field components are de-signed to withstand damage caused due to extreme heat and pressure of combustion process. Many of experimental studies regarding the internal combustion engines process have been carried out, but few had only focused on the numerical studies like stress distribution, thermal and heat transfer analysis. This present study focuses on a 3-D transient state temperature dis-tribution analysis on a gasoline piston model of a tri-cycle. Mathematical model was formulated, solved and simulated using a Finite Element Method (FEM) in-built in the COMSOL Multiphysics software 4.3a to determine the temperature distribution and gradient of the piston model ranging from 523K – 673K. The parameters used for the simulation were liquid (Gasoline), Gases (Air) and Aluminium alloy UNSA96061 (Piston). The Completed mesh tetrahedral consists of 86225 elements and the number of degrees of freedom solved for were 18553 in 367 s (6 minutes, 7 seconds) in the mesh optimization. It was discovered from the results obtained that the temperature in the combustion chamber of the tricycle engine varies with respect to time, along the pis-ton.The transient analysis from the time dependent solver revealed that the temperature of the piston at the TDC (Top Dead Centre) in the first power stroke is higher compared to the subsequent power strokes, which is an indication that more heat was transfer at subsequent power strokes. Probable recommendations were later made.
Evaluation of the Structural Performance of Lateritic Soil Stabilized with Cassava Peel Ash (CPA) and Cement
(ARC journals, 2016-07-04) Olutaiwo, Adeoluwa; Adanikin, Ariyo
This study presents the result of experimental investigation on the evaluation of the effects of Cassava Peel Ash (CPA) on the index and structural properties of lateritic soil of A-7-5 (AASHTO Classification) and SP soil (USCS classification) respectively. The study was in two phases, firstly with the addition of CPA only by weight of dry soil and secondly with the addition of 5% cement with the CPA by weight of dry soil. The CPA additions were performed using 0, 2, 4, 6, 8 and 10% increment by weight of dry soil thoroughly mixed. The results of the treated soil showed that the index properties: plastic limit and the maximum dry density (MDD) decreased as the CPA addition increased whereas the liquid limit, plasticity index, Optimum Moisture Content (OMC) and California Bearing Ratio (CBR) increased as the CPA content increased. It was also discovered that the Unconfined Compressive Strength (UCS) increased up to 4% of CPA addition after which was a reduction. This implies that CPA possesses the potential for use in the modification/ stabilization of lateritic soils. Thus the use of CPA in road construction works can be said to have two major advantages – as an effective agricultural waste management and the improvement of road construction soils for better road performance.
PUBLIC TRANSPORT POLICY IN DEVELOPING COUNTRIES: NIGERIA AS A CASE STUDY
(1st International Conference of the School of Management Technology (SMAT), 2017-03) Adanikin, Ariyo; Oyedepo, O. Joseph
This paper reviewed understudies public transport approach utilizing factors such urbanization, populace development, vehicle proprietorship, and utilization. With changes in the social, political and economic climate of Nigeria, this study looks at how these changes have affected transportation request and supply, transport arrangement and directions, and parts of economic aspects and fund identified with public transport. Conservation and enhancing of existing modes, effective utilization of people in general transport administration framework, executing appropriate transportation measures, and empowering a move towards reasonable modes were suggested. Review of government policies towards public transportation was undertaken and it shows that if developing nations like Nigeria are to achieve their economic transformation blueprint such as the Millennium Development Goals (MDGs), they require a functional, reliable and effective transport system to, among other things, connect people, places, services, opportunities and all these can only be derived by properly formulated and implemented policies with the aid of all relevant private, academic and government bodies working together.
Crack Mechanism of Different Concrete Grades under Compressive Loading: Application in Rigid Pavement
(FUOYE Journal of Engineering and Technology, 2017-03-31) Oyedepo, Joseph O.; Dada, Temitope; Aladegboye, Segun; Adeniji, Akintayo A.
The growth of cracks in concretes under different loadings in various structures and their consequent diminishing effect on the lifespan of structures is an age long structural problem. This research investigates the influence of compressive loading on the crack mechanism of different concrete grades 1: 1 : 3 (M20), 1: 2: 4 (M15) and 1: 3: 6 (M10) using three brands of cements available in Nigeria namely Dangote (Type A), Elephant (Type B) and Bua (Type C). Particle Size Distribution (PSD), Aggregate Crushing Value (ACV), Aggregate Impact Value (AIV) was carried out on aggregates in accordance with relevant codes while; compressive test were performed on the hardened concrete while, the crack width was measured using microscopic technique. A coefficient of uniformity (Cu) of 4.00, AIV of 46 % and an ACV of 47.7 % were obtained for the aggregate which are suitable for rigid pavements construction. Maximum compressive strength value of 24.96 N/mm2 , 24.67 N/mm2 and 24.89 N/mm2 respectively was obtained for concrete M20 for Type A, Type B and Type C cement at the 28 day. A corresponding crack width of 0.97 mm, 0.89 mm and 0.93 mm was obtained while; a yield period of 57.66 sec, 58.33 sec and 53.33 was obtained respectively. Comparing with the International Organization for Standardization, concrete grade M20 any of the cement types is suitable for the construction of rigid pavements with heavy traffic volume while M15 is recommended for low traffic volume.
Performance Study of University of Ado Ekiti (UNAD) Transit Shuttle Buses
(Science Publishing Group, 2017-06-01) Adanikin, Ariyo; Olutaiwo, Adewale; Obafemi, Tobi
Traffic engineering uses engineering methods and techniques to achieve the safe and time efficient movement of people and goods on roadways. The safe and time efficient movement of people and goods is dependent on the transit system performance, which is directly connected to the traffic characteristics. The main parameters of performance of transport shuttles are traffic volume, speed, density and revenue; and all these are evaluated in this study. In the absence of effective planning and traffic management, current road infrastructure will not be able to cater for the future needs of the University. Students, staff and vehicle volumes have increased significantly in the last decade in the Institution, yet the performance of the transport shuttle have been dismal and unable to achieve its objectives. Findings of the study show that the morning peak period (8.00am to 9.00am) has 234 vehicles/hr, evening peak period (2.00pm to 3.00pm) has 284 vehicles/hr, while the offpeak period (11.00am to 12.00pm) has 156 vehicles/hr. The journey time from the Post Office bus stop to the University campus, measured as 34.01 minutes, was too long for the distance of 15.0km road which according to the Nigeria Highway Code should not be more than 18 minutes. The average stopping time was 6.55 minutes, average interval between arrivals of motorists was 16.40 seconds, the average queue length was 14.23 people, and the average waiting time at the bus-stop 4.17 minutes. These values were obtained using the queuing theory and shows much commuters time is lost on transit queues. The financial condition of the transit unit shows that amount generated is less than the amount expended by the transit operators. This means, in effect, that the shuttle bus operators are operating in deficit.
PUBLIC TRANSPORT POLICY IN DEVELOPING COUNTRIES: NIGERIA AS A CASE STUDY
(SMAT FUTA, 2017-07-02) Adanikin, Ariyo; Oyedepo, Joseph O.
This paper reviewed understudies public transport approach utilizing factors such urbanization, populace development, vehicle proprietorship, and utilization. With changes in the social, political and economic climate of Nigeria, this study looks at how these changes have affected transportation request and supply, transport arrangement and directions, and parts of economic aspects and fund identified with public transport. Conservation and enhancing of existing modes, effective utilization of people in general transport administration framework, executing appropriate transportation measures, and empowering a move towards reasonable modes were suggested. Review of government policies towards public transportation was undertaken and it shows that if developing nations like Nigeria are to achieve their economic transformation blueprint such as the Millennium Development Goals (MDGs), they require a functional, reliable and effective transport system to, among other things, connect people, places, services, opportunities and all these can only be derived by properly formulated and implemented policies with the aid of all relevant private, academic and government bodies working together.
Structural Evaluation of the Effect of Pulverized Palm Kernel Shell (PPKS) on Cement-Modified Lateritic Soil Sample
(Science Publishing Group, 2017-11-01) Adanikin, Ariyo; Olutaiwo, Adewale; Ajisafe, Segun
There have been global efforts to reduce environmental pollution of agricultural and industrial waste products by utilizing such wastes as stabilizing agents to improve soils for various uses, especially road construction. In this research, lateritic soil sample obtained from a borrow pit was tested with varying percentages of Pulverized Palm Kernel Shell (PPKS). The soil was classified as A-6 (AASHTO classification) using standard soil laboratory tests. Laboratory tests such as Atterberg Limits, Compaction, Unconfined Compressive Strength (UCS) and California Bearing Ratio (CBR) were conducted on the soil + PPKS mix only and also on soil + PPKS + 3% Ordinary Portland Cement (OPC) mix. The liquid limit (LL) and plasticity index (PI) values decreased steadily with increase in PPKS while the plastic limit (PL) value increased with up to 4% PPKS addition after which the values started decreasing. The shrinkage limit (SL) value increased with a peak value at 8% PPKS addition after which the values began to decrease. The Optimum Moisture Content (OMC) results on PPKS addition increased from 16% to 19.5% while the Maximum Dry Density (MDD) decreased by 45.18% from 1.669g/m3 to 0.915g/m3 . Addition of PPKS decreased the Unsoaked CBR by 10.79% from 68.60 to 61.20% while the Soaked CBR increased by 74.12% from 18.05% to 69.75%. UCS values for the lateritic soil and PPKS for the uncured sample, at 7 days and 14 days had peak values of 85.03, 96.46 and 100.44 respectively. From the study, it can be concluded that the properties of the Lateritic soil improved when stabilized with Cement and pulverized palm kernel shell compared to when it was stabilized with pulverized palm kernel shell alone
DESIGN AND DEVELOPMENT OF A WEAR TESTING MACHINE FOR MANUFACTURING LABORATORIES
(1st FUOYE INTERNATIONAL ENGINEERING CONFERENCE, 2018) Ogedengbe, Temitayo S.; YUSSOUFF, Abiodun A.; Adanikin, Ariyo
Wear of parts during manufacturing processes is inevitable but controllable. Therefore, the critical study of wear in engineering components is vital because failure of components due to wear has resulted in loss of a great deal of fortune. This study was therefore an attempt to design and fabricate a wear testing machine, evaluate the performance of the machine and compare data obtained with existing ones. Materials for the various parts were carefully selected based on desirable properties and availability. Design calculations were made for the main shaft, compression spring, belt, pulley and electric motor. The post fabrication test was carried out on the machine to evaluate the performance of the machine and results gotten reported
Numerical Simulation and Modeling of UNSA91060 for Heat Transfer in Four-Stroke ICE Cylinder Head
(International Journal of Advanced Engineering, Management and Science (IJAEMS), 2018-03) Adesina, Olaiya Kamorudeen; Olanrewaju, Alabi Ismaila; Abolanle, Falana Kafayat
Heat transfer is one of a number of indispensable tools in studying of ICEs, due to its influence on decisive parameters of operation like temperature and pressure inside the cylinder. It is safe to say that modeling of the engine heat transfer is among the most complex problems for engineers. Application of numerical methods to predict the heat transfer in a cylinder of reciprocating ICEs is a process of high importance, which was recognized from the earliest stages of their development. This is done to examine performance optimization and design improvement in order to meet nowadays demands exhibited on the engines. This present study focuses on a 3-D transient state temperature distribution analysis on a gasoline engine model via formulated of models, simulating using FEM in-built in the COMSOL Multiphysics software 4.3a to determine the temperature distribution and gradient of the engine cylinder head model. The number of degrees of freedom solved for were 32685 in 383 s (12 minutes, 20 seconds) in the mesh optimization. From the result obtained it was discovered that the heat transfer in the combustion chamber of the ICE varies with time. Thus, it took the engine 10 minutes to complete a cycle vis-a-vis transfer of heat after combustion and that the heat transfer starts after 30 seconds of combustion. In addition, the temperature of the cylinder dropped from 1273.2 K to 301 K over a period of 10 minute.
Assessment of the Strength of Conventionally Produced Sandcrete Blocks and Burnt Bricks
(IOSR Journals, 2018-03-15) Adanikin, Ariyo; Jegele, Thompson
The fact remains that housing has been universally acknowledged as the second most important human need after food. It has been of perennial interest to the world at large since its availability touches on one of the widest spectrum of human existence. Sandcrete blocks as building materials have become so popular in many parts of Africa that although similar to bricks in many respects, they both deserve to be treated separately. It is therefore worthy of note that for an engineer to select one of these materials (block and brick), the fitness or suitability of the chosen materials for the purposed structure must be considered.Tests carried out in this research include sieve analysis, Atterberg’s limit tests (Liquid limit and plastic limit) were carried out on the materials (sand andlaterite)to be able to ascertain certain of their properties for their intended use. About ten pieces each of sandcrete block and burnt bricks were prepared for the study and density and compressive strength tests were carried out on them. Findings of the study shows the samples Liquid Limit to be 32%, Plastic Limit of 16.7%, density of the sandcrete block is 1947.47kg/m3 while the density of the burnt brick is 1823.58kg/m3 .The average compressive strength of burnt brick (5.20N/mm2 ) was found to be higher than that of sandcrete block (3.15N/mm2 ).This shows that the compressive strength is directly proportional to the crushing load on the specimens and this is shown by the regression equation y = 0.2129x+1.5;R² = 0.9817 for the burnt bricks and y = 0.14x + 0.7; R² = 0.9942 for the sandcrete blocks.The study therefore concludes that burnt bricks just like sandcrete blocks is a good construction material and can be used for sustainable building construction.
MECHANICAL STRENGTH DETERMINATION OF CRUSHED STONE AGGREGATE FRACTION FOR ROAD PAVEMENT CONSTRUCTION (CASE STUDY: SELECTED QUARRIES IN WESTERN NIGERIA)
(FUOYE, 2018-07-06) Adanikin, Ariyo; Olutaiwo, Adewale; Ashamo, A
In this research work, the mechanical strength of crushed stone aggregate fractions for road pavement construction in Western Nigeria was assessed. Samples of crushed stone aggregates were collected from nine (9) representative quarries spread across the states in Western Nigeria.The physical and mechanical properties of the aggregates were evaluated. The results were then compared with the specifications in international standards (BS and ASTM Standards). All the aggregate samples met the required limit for Loose Density, Water Absorption, Aggregate Crushing Value (ACV) and Aggregate Impact Value (AIV) tests. Aggregates samples from Samchase, Kopek, CCECC and SaliwaYetidipe quarries have flakiness indices exceeding the permissible limit (29.5%, 25.7%, 27.9% and 34.5% respectively). Hi-Tech and Western quarries samples have elongation indices of 44.5% and 40.3% respectively which are higher than the permissible limit. The two samples that failed Aggregate Abrasion Value test (AAV) are Hi-Tech and Western quarries, having 30.8% and 30.4% respectively. These two aggregates samples have AAV less than 35% which means they are still good for pavement construction only if the appropriate guidelines are followed (since any aggregate with AAV more than 35% is deemed weak for pavement construction). The study concluded that aggregates from Julius Berger quarry have the highest mechanical strength.
TREATABILITY STUDIES ON RAW WATER FROM APONMU RESERVIOR IN ILARA – MOKIN, , NIGERIA
(Proceedings of the OAU Faculty of Technology Conference 2019, 2019) Oke;, I.A.; Daramola, D.A.; Adeniji, A.A.; Fakorede, E.O.; Adanikin, Ariyo; Olabode, K.O.; Aladeyelu, A.; Arowolo, O.K.; Agada, O.V.; Agboola, A.; Gabriel, O.
Adequate water supply is an important ingredient in human’s development. In this study, samples of war water were collected from Aponmu reservoir at Elizade University, Ilara – Mokin , Ondo State, Nigeria at intervals of one week for six months. These water samples were subjected to laboratory studies (Column, pH adjustment, Jar and residual chlorine tests). Laboratory analysis of flocs formation during coagulation, iron and microbes removal of chlorination process, pH adjustment and residual chlorine after treatment of the samples were conducted using standard methods in a bench scale and executed at prototype phase. Iso-concentration curves were developed from column tests to ascertain settle-ability of the flocs during treatment. The study revealed that optimum doses of coagulant and chlorination were 80 mg/l, and 10 mg/l, respectively for effective removal of iron and residual chlorine concentration of 3 mg/l. Flocs removal was 65 % of the influent flocs in the coagulated raw water at a depth of 1.2 m and at a retention time of 60 minutes. Analysis of iso-concentration curves revealed that overall flocs removal was 89 % at 60 minutes. This indicated that for a retention period of an hour 350 mg/l of flocs would be removed from the coagulated raw water. Removal of iron from the coagulated water was between 90 and 95 % of initial iron concentration of 1.42 mg/l and removal of microbes was 99.1 % at retention time of 40 minutes. It was concluded that Aponmu reservoir can be used as water source with little modification of the current facilities, but further studies are required to ascertain effects of other factors (quality of raw water, rainfall intensity, time of concentration, discharge rate) on quality of water production.
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
Quality Assurance of Available Portland Cements in Nigeria
(International Journal of World Policy and Development Studies, 2019) Ikumapayi, Catherine Mayowa; Oluwabusuyi, Fakorede Ebenezer
increment in manufacturers to be had in our day. These in turn amongst others have brought about failure of buildings and other construction members. As a result, the need to ensure the quality of available cement in circulation is of utmost paramount. This research work studies the available Portland lime cement of grade 42.5 only, in Nigeria from such company as company A, company B, and company C. The qualities and properties of the Portland lime cement from every of the above-named companies were investigated and as compared. Properties like Fineness, Setting Time, Chemical composition, Specific gravity, Consistency, Loss of ignition, Strength (compressive strength, and flexural strength), Micro structural analysis were determined according to relevant BS EN 197-1 (2011) and (ASTMC) 150-92 standards. These tests were carried out with the usage of scanning electron microscope, X-ray fluorescence spectrometer, Vicat apparatus, compressive strength machine, consistency apparatus and Chatelier flask, among others. The results showed that the chemical composition mostly of CaO, SiO2, AL2O3 and MgO in the cement +are within the acceptable limit of 60.0-67.0, 17.0-25.0, 3.0-8.0 and 0.1-4.0 respectively in the BS 4550: Part 3 (1979). The results of the compressive strength acquired for all the cement have been a way beneath the standardized result expected for grade 42.5. These could partly be traced to the cement micro-structure as Company C with the best morphology exhibits better compressive strength than others. Improvement on the cement morphology by the manufacturers could lead to compressive strength improvement. It was also discovered that one of the important factors that would have contributed to the low compressive strength was excessive amount of silt/clay content material inside the sand used.
INCESSANT POWER SUPPLY IN NIGERIA AND THE NEED FOR THE DESIGN AND PRODUCTION OF 100,000MW POWER PLANT
(International Journal of Scientific & Engineering Research, 2019-02) Oshin, Ola A.; Adanikin, Ariyo; Fakorede, Ebenezer O.; Joseph, Ojotu
The present unreliable and erratic power supply is a pointer to the fact that there is a great need for fault evaluation and reliability studies of electric power system in Nigeria. The recent blackout in the country has grounded many activities and has destroyed many industrial processes. Also, the power industries face a lot of problems. Some of the highest priority issues being generation of sufficient power, urgent clearance of faults, adequate protection and increase reliability of the system, that is, bringing a steady uninterrupted power supply to the consumers. The Nigerian power problem resulted to incessant planned, forced and unplanned outages. In addition, it has resulted to erratic and unreliable supply of electricity in the country. It has reduced productivity and has increased unemployment rate in the country to over 40million (this figure is over 70% of Nigerian youths. It has led many of the youths in the country to crime. It has led many of the deaths of many innocent people in the country. Hence, an analytical method is developed to assess the dynamic- reliability of the distribution system, as well as optimizes the occurrence of faults along each of the individual consumer point in a feeder in order to improve the performance of the system. This research publication therefore evaluates the occurrence of faults which is about 856 occurrences during a period of 8 years and outages which range between 1118 to 3785 hours per annum along the distribution lines, also the failure rates of each of the feeders were analyzed in order to improve on the supply of electricity in the distribution network. The reliability of the system which ranges between 8.57*10-12 to 9.548*10-5 were analyzed; and fault clearing techniques were carried out. Efforts were made to adequately assess the failure rates of the feeders which range between 0.003 and 0.001 and reliability of the distribution system. Efforts were also made to improve the performance of the system. As a result, it was possible to establish improvement techniques which ensure adequate and constant supply of electricity to all the consumers for industrial growth and employment: a basic solution to increasing crime rate in the country.

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