| 1 |
Author(s):
J. O. Jeje.
Page No : 1-9
|
Study of Water Filtration Without Chemical Pre-Treatment
Abstract
This research work focused on studying water purification without chemical pre-treatment. In the studies, alternative approaches were carried out to develop a filter bed suitable for filtering water without the use of chemical treatments that is also cost effective. Polyvinyl Chloride (PVC) pipes (100 × 1700) mm were used as filter boxes. The experiment carried out during the study was divided into two major parts; that is slow sand and rapid sand filter parameters. The slow sand filter consisted of two filter pipes, one consisting of a stratified layer of sand of size range of 0.20 – 0.60 mm with a depth of 700 mm as filter medium. The turbidity, filtration rate and head loss of the effluent across the filter were monitored for 15 days. It was found that slow sand filter plus granular activated carbon (GAC) and rapid sand filter plus GAC were more effective in the removal of turbidity. Turbidity reduced with the increase in time. Rapid sand filter was found to be the least effective in the removal of bacteria while slow sand filter plus GAC was the most effective. The slow sand filter unit gave a very high coliform count compared to other filter units. It was found that the filtration rate plays a vital role in the mechanism of filtration.
| 2 |
Author(s):
A.B. Waziri, A. Tokan, Maidawa Haruna, O.B. Umaru, N. Mohammed, I. M. Abdullahi, G.B. Muhammad.
Page No : 10-16
|
An Evaluation on the Effect of Natural Fibres on the Mechanical Properties of Kenaf-Coir Hybrid Composite
Abstract
Over the past few decades, we find that polymers have replaced many of the conventional metals/materials in various applications. This is possible because of the advantages polymers offer over conventional materials. The most important advantages of using polymers are the ease of processing, productivity, and cost reduction. In most of these applications, the properties of polymers are modified using fillers and fibres to suit the high strength/high modulus requirements. Fibre-reinforced polymers offer advantages over other conventional materials when specific properties are compared. These composites are finding applications in diverse fields from appliances to space crafts.
| 3 |
Author(s):
G. O. Adunoye, O. T. Akanbi, G. H. Odusina, A. S. Faloye.
Page No : 17-25
|
Engineering Characteristics of Soils Reinforced with Shredded Plastic Waste
Abstract
There is a continuous attempt at seeking different, economical and environmental-friendly means of improving the strength of soils. This work therefore studied the effects of shredded plastic waste (SPW) on the strength of selected soils. To achieve the aim of the study, lateritic soil samples were collected from two identified active borrow pits in Ile-Ife. Following standard procedures, the following tests were conducted on the soils in their natural state: natural moisture content, grain size analysis, specific gravity, Atterberg limits, compaction, and California bearing ratio (CBR). Subsequently, the soils were treated with SPW in 4 %, 8 % and 12 % proportion by weight of soil respectively. They were then subjected to compaction and CBR tests. The natural soils were found to have the following characteristics for sample A and sample B respectively: specific gravity (2.70 and 2.51); liquid limit (40.40 % and 61.00 %); plastic limit (23.11 % and 36.67 %); plasticity index (17.29 % and 24.33 %); American Association of State Highway and Transportation Officials (AASHTO) classification (A-3 and A-2-7); maximum dry density (MDD) (1430 kg/m3 and 1510kg/m3); and optimum moisture content (OMC) (21.13 % and 48.0 %). Results further showed that the addition of SPW led to a slight improvement in the strength characteristics of the tested soils. The study concluded that SPW could be used to improve the strength of lateritic soils.
| 4 |
Author(s):
M. O. Ajala, O. O. Ajide, N. Idusuyi.
Page No : 26-39
|
Development and Evaluation of Respirometric in Situ Corrosion Monitoring System
Abstract
There is a growing need for a system to be used for real-time in-situ monitoring of corrosion rates. This system/method allows the determination of real-time corrosion rates under realistic exposure conditions and is capable of following changing exposure conditions in situ. This is realized by a combination of optical Oxygen sensor measurements with either gravimetric volume sensitive techniques or pressure sensor based techniques in a closed chamber. This study was therefore aimed at developing and evaluating a low-cost, real-time corrosion monitoring system, using copper (Cu) as a test sample. Materials used were sourced locally, the circuitry was designed and used to develop the system with incorporation of sensors that can monitor temperature, humidity and pressure within an airtight glass bottle and placed in a housing which was fabricated. The developed system was then evaluated using a piece of Cu exposed to 5% Sodium Chloride (NaCl). Hydrogen evolution reaction (HER) and Oxygen Reduction Reaction (ORR) within the closed chamber were monitored; and thus Ideal gas and Henry laws were adopted to calculate the amount of gas molecules, and convert them to cathodic reactions. The methods were carried out in accordance with existing literature and standard procedure. Results of evaluation of the system showed that, the more Oxygen is being consumed, the higher the corrosion. Mass loss validation measurements carried out at the end of exposure showed a good correlation with the total recorded cathodic charge. Immersion corrosion kinetics can be monitored non-destructively and in real-time. Manometric approach showed that HER leads to a pressure increase while ORR leads to a decrease in pressure. ORR monitoring is possible based on the amount of consumed O2 by manometric and sensor-based approaches; sensitive, non-destructive corrosion rate measurements are possible on Cu and could be monitored remotely.
| 5 |
Author(s):
Oladimeji O.A., Akomolafe M.A., Lasisi T.A.3, Oloja O.A., Oladimeji L.A..
Page No : 40-52
|
Network Analysis on Phase 1B Building of the University Health Centre, FUTA, using Critical Path Method (CPM) and Program Evaluation Review Technique (PERT)
Abstract
Project planning and scheduling plays a vital role in estimating the time and cost angle of a project. Finalizing a project on time and within the budget is challenging. This study focused on finding the shortest possible time required to complete the phase 1B Building project of the University Health Centre, FUTA and also to evaluate the probability of completing the project within the stipulated time. This project work has been able to give a concise view about network analysis in building construction; definitions of some terms commonly used in network analysis was also stated. Also, an introduction to CPM and PERT was stated; assumptions of CPM, advantages and disadvantages of CPM were stated; assumptions, advantages and disadvantages of PERT were also stated. Data analysis was carried out and all the possible routes of the activities involved in the building project were found; the location of the critical path of the building project was also found; the expected duration for every activity in the building project was determined; the probability of completing the project within the stipulated time was also evaluated. The results showed that there is a 50% chance for the project to be completed within the stipulated time. With the information gathered on the building project, the project was delayed due to some factors such as low circulation of money, inadequate equipments, loss of some weeks due to a change in plan, and inadequate manpower; thus, there was a two month difference between the initial completion and the now actual completion time.
| 6 |
Author(s):
K.D. Oluborode, I.O. Olofintuyi, O.R. Olulope.
Page No : 53-60
|
Comparison of Effects of Alkaline Activator Molarity and Cure Temperature for Geopolymer Synthesized from Alternative Laterite Sources
Abstract
Geological source material remains one of the options for developing countries to participate in deployment of geopolymer material technology for environmental friendly infrastructure development. Geological source materials for geopolymer are heterogeneous in nature. This study sort to investigate and provide information for aggregation of repository comparative information on geopolymer specimen properties of alternative source material and their response to effect of alkaline activator molarity and cure temperatures. Pulverized 750°c calcined laterite obtained from two alternate sources were activated with alkaline activator solution of NaOH of 8M, 10M, and 12M with NaSiO3 and sterile water of ratio 7:3:3 were properly mixed at activator to source material ratio of 0.45. 50×50×50 specimen cubes were cast for density, porosity and comprehensive strength test for specimen cure at 27°c (room temperature), and 50°c and 90°c in oven temperature respectively for 28 days and 72 hours. The study shows that in each geopolymer specimen source material, the density of the specimen decreases with increased cure temperature while specimen porosity increases with increased cure temperature. Increased activator molarity increases the density of the specimen while specimen porosity does not follow a definite trend with activator molarity. Ekiti parapo pavilion laterite based geopolymer specimen has minimum density, porosity and comprehensive strength of 2.15 g/cm³, 5.27% and 1.74 N/mm². Geopolymer specimen based on polytechnic gate source material have density, porosity and compressive strength minimum values of 1.86 g/cm³, 11.46% and 0.58 N/mm2.. Their corresponding maximum values are respectively 2.40 g/cm³, 19.24% and 14.92 N/mm2 for pavilion based geopolymer specimens, 2.33 g/cm³, 26.08% and 6.90 N/mm².
| 7 |
Author(s):
Iwekumo Stevyn Akosubo, Charles Kennedy.
Page No : 61-80
|
Potential Influence of Albizia Lebbeck on Corrosion Effect of the Bond Between Steel and Concrete
Abstract
This study aimed to investigate the effects of corrosion on the bond strength between reinforcing steel and concrete and the potential of using exudate coating to improve the bond strength in corrosive environments. The finding showed that the failure load and bond strength of corroded concrete cube specimens were significantly lower than non-corroded control cube specimens. The use of exudate coating on steel reinforcements, however, can significantly improve the pullout bond strength in corrosive environments. The study also showed a slight reduction in the measured rebar diameter for corroded specimens compared to non-corroded specimens. The Albizia lebbeck exudate-coated steel bars showed higher bond strength and maximum slip values compared to non-corroded control specimens, indicating that the exudate coating may have provided protection against corrosion. Further research into the long-term effects of using Albizia lebbeck exudate-coated steel bars and the cost-effectiveness of this method is required.
