DEPARTMENT OF CIVIL ENGINEERING

This study examines how curing reinforced concrete in a urea-salt solution, which simulates urine, affects its compressive strength and durability. This is compared to concrete cured in fresh water. The research addresses concerns about the decline of concrete structures in environments that are biologically or chemically harsh, such as areas often contaminated by urine. Understanding the impact of such exposure on concrete performance is important for improving the design and maintenance of durable structures under these conditions. The experimental work involved casting twenty concrete cubes, each measuring 100 × 100 × 100 mm, using a mix ratio of 1:2:4 and a water-cement ratio of 0.5. Ten cubes were cured in fresh water, while the other ten were cured in a urea-salt solution made with 10 g of urea and 2 g of sodium chloride (NaCl) per liter of water. The cubes were tested for compressive strength after 14 and 28 days of curing using a compression testing machine. The data gathered were analyzed and compared to evaluate the impact of the urea-salt solution on concrete performance. The average compressive strengths were 18.81 N/mm² and 23.17 N/mm² for the 14- and 28- day fresh-water samples, and 18.15 N/mm² and 17.81 N/mm² for the urea-salt-cured samples which indicates that concrete cured in fresh water showed normal strength growth with age. In contrast, the concrete cured in the urea-salt solution had a slight decrease in compressive strength over time. It was concluded that exposure to the urea-salt solution restricts full hydration and weakens concrete durability with extended contact. It is advised that structures in areas prone to urine contamination be shielded from direct exposure.

This study investigates the environmental impact of the Ekosodin dumpsite in Benin City, Edo State, on surrounding groundwater quality, specifically addressing the risks of leachate infiltration. The research aim was to evaluate twenty-two physicochemical and microbial parameters across eight sampling locations to determine the spatial extent of contamination and assess the suitability of local water resources for domestic use. By benchmarking these parameters against World Health Organization (WHO) and Nigerian Industrial Standards (NIS), the study provides a comprehensive overview of how inadequate waste management practices threaten the availability of safe potable water for the community. The methodology integrated systematic laboratory analysis with advanced geospatial modeling using ArcGIS 10.8. Groundwater samples were collected from eight borehole locations and analyzed for various physical, chemical, and biological properties, including heavy metals like Lead (Pb) and Cadmium (Cd). A Water Quality Index (WQI) was calculated for each site to classify water quality, while Inverse Distance Weighting (IDW) interpolation was applied to map the spatial distribution of pollutants. Furthermore, a Multiple Linear Regression (MLR) model was developed to quantify the relationship between five key parameters—including Electrical Conductivity (EC) and Iron (Fe)—and the calculated WQI, achieving a high predictive accuracy with an R 2 value of 0.9983. Results revealed a significant degradation gradient, with WQI values ranging from 27.20% to 130.05% (and up to 945.24% in specific computations), indicating that boreholes closest to the dumpsite possess very poor water quality unsuitable for drinking. Spatial analysis confirmed the dumpsite as the primary source of elevated heavy metals and organic contaminants, though quality generally improves as the distance from the waste source increases. The study concludes that leachate from the Ekosodin dumpsite severely impairs groundwater safety, leading to the recommendation that future boreholes be sited at least 400 meters away from disposal areas. These findings emphasize the urgent need for modernized waste management strategies and continuous groundwater monitoring to protect public health and ensure a sustainable water supply.

Manual pavement inspection methods are slow, subjective, and often inconsistent, leading to delayed maintenance and increased road deterioration. This study was carried out to develop an automated, image-based system capable of detecting and classifying visible defects in flexible pavements using machine learning. The objectives of the study were to review existing pavement inspection techniques, collect and preprocess pavement image data, and design and train a model capable of identifying pavement failures accurately. The study was with the aim of improving the speed, objectivity, and reliability of pavement condition assessments. A dataset of pavement images was obtained from the Edo State Ministry of Works, field surveys, and public sources. The images were annotated in YOLO format and augmented by flipping, rotation, cropping, and brightness adjustment. The YOLOv8 object detection model, implemented in Python using TensorFlow, PyTorch, and OpenCV, was trained on Google Colab with an NVIDIA T4 GPU. Training was performed at varying epochs (50, 100, and 200) and hyperparameters to optimize detection performance. The model’s accuracy was evaluated using mean Average Precision (mAP) and recall metrics to assess its ability to detect cracks, potholes, and rutting in flexible pavements. Results showed that the model achieved a mean Average Precision (mAP₅₀) of 0.68 and recall above 0.80 for visible defects such as potholes and alligator cracking, at a confidence level of 0.5. The model was less effective in detecting faint, low-contrast linear cracks. This study concluded that YOLOv8-based models can effectively automate pavement distress detection, providing a faster and more reliable alternative to manual inspection. It is recommended that future work expand the dataset and explore enhanced training strategies to improve the detection of subtle linear cracks.

This project examined the environmental and health hazards from the disposal of liquid waste generated by industries, particularly those involved in beverage production in Nigeria. Increased urbanization and rapid industrialization have occasioned increased volumes of effluent being discharged, usually without proper treatment, into River Niger and other water bodies. This results in various forms of pollution, contaminating the organic and inorganic content, ultimately causing about 25% of all preventable diseases, including waterborne diseases. This research work aimed to study and upgrade the liquid waste disposal methods at the International Breweries Limited Onitsha, Anambra State. Specific objectives included establishing the physical, chemical, and biological characteristics of the effluent and also appraising the sustainability and efficiency of the existing effluent treatment and disposal processes with respect to compliance with WHO standards.The methodology used in this research involves a case study approach at the brewery plant. Effluent samples were collected from pre-treatment and post-treatment points during the month of August, at morning periods to capture peak production waste. Each sample size was 2 liters, preserved at 4°C, and conveyed to the laboratory within 4 hours. Physical parameters such as pH, temperature, turbidity, total suspended solids, and color were analyzed using calibrated instruments like pH meters and spectrophotometers. Chemical parameters for biochemical oxygen demand, chemical oxygen demand, heavy metals, and nutrients were analyzed by digestion followed by atomic absorption spectrophotometry. Biological parameters-total heterotrophic bacteria, coliform counts, and E. coli-were determined by membrane filtration and incubation on selective media. Data analysis involved the use of descriptive statistics and comparison with WHO benchmarks. These results portrayed partial efficacy of the treatment. Physical parameters were improved, with turbidity falling from 1.0 NTU to 0.5 NTU; however, pH and total dissolved solids were still above WHO limits at 5.0 and 2829 mg/L, respectively. The chemical parameters were reduced-for instance, COD was reduced from 80.1 mg/L to 56.3 mg/L-but remained high, as were heavy metals (e.g., lead, 0.74 mg/L> 0.01 mg/L) and nutrients (ammonia, 8.74 mg/L> 0.5 mg/L); thus, offering a high risk for eutrophication and toxicity. Biological parameters were fully met, as coliform and E. coli counts were nil after treatment. -The study concluded that the brewery's treatment system was inefficient to achieve full compliance, with the need to invest in effective treatment technologies such as reverse osmosis and nutrient removal. Individuals should advocate for clean water practices, corporate organizations should invest in advanced treatment technologies, and government agencies should establish stricter monitoring and incentives for sustainable waste management.

The behaviour of shallow foundations constructed on lateritic soils is of significant importance in tropical regions where these soils occur extensively and are commonly used for civil engineering works. Lateritic soils are highly variable in nature, and their engineering performance is strongly influenced by factors such as mineral composition, moisture content, degree of compaction, and environmental conditions. This variability often leads to challenges in predicting foundation performance and ensuring structural safety. This study investigates the behaviour of shallow foundations on lateritic soils through a combination of field and laboratory investigations. Field studies include soil sampling an in-situ tests to assess the natural state of the lateritic deposits. Laboratory tests are conducted to determine the index properties, compaction characteristics, shear strength parameters, and bearing capacity of the soils. Model and empirical methods are employed to evaluate the load-bearing capacity and settlement behaviour of shallow foundations under different soil conditions. The results of the study establish relationships between key soil properties—such as moisture content, density, plasticity, and strength—and the performance of shallow foundations. The findings provide valuable insight into the load-bearing behaviour of lateritic soils and highlight the importance of proper soil characterization in foundation design. The study aims to contribute to safer and more economical design practices for shallow foundations in lateritic soil environments, particularly in tropical regions.

Building collapse remains a persistent challenge in urban areas across Nigeria, with Benin City experiencing a notable frequency of structural failures. It is a devastating phenomenon that leads to the destruction and loss of property and lives This paper represents a study on the hierarchical assessment of the underlying factors causing building collapse in the city of Benin. Utilizing a multi-criteria decision-making approach, the research categorizes and ranks the causes based on expert interviews, field observations, and documented case studies. Key factor examined include poor construction practices, substandard materials, inadequate regulatory enforcement, design flaws, and environmental influences. The hierarchical assessment process employs the use of structured questionnaire to gather data from professionals in the construction industry and ranks these causes based on the most voted factors into primary, secondary and tertiary factors revealing poor construction materials, inadequate supervision and regulation, corruption, poor workmanship and repurposing of buildings to be the most primary factors. Lack of proper engineering design, overloading, poor foundation work, weak enforcement of building codes and member failure to be secondary factors. Negligence and lack of maintenance, rapid urbanization and natural disasters to be tertiary factors. Recommendations to curb or reduce the issue of building collapse in the city of Benin are strict enforcement of building codes and regulations, quality control and material testing, enhanced professional training and certification, combating corruption, public awareness campaign, urban planning and zoning regulation, promotion of preventive maintenance, establishment of a building collapse response task force, encouraging use of technology in construction.

The increasing reliance on sachet water as a primary source of drinking water among students in
Ekosodin underscores the need for rigorous quality assessment. This study investigates the physicochemical and microbiological characteristics of various sachet water brands consumed in the region. Parameters such as pH, turbidity, total dissolved solids (TDS), and the presence of microbial contaminants were analyzed using standard laboratory techniques. The study aims to determine compliance with regulatory standards and assess potential health
risks associated with these products.

Water-logged soils are a persistent challenge in geotechnical engineering, especially in tropical regions where high rainfall and poor drainage lead to saturated ground conditions. These soils typically exhibit low shear strength, high compressibility, and poor load-bearing capacity, making them unsuitable for construction without prior treatment. In this study, bamboo ash, especially bamboo leaf ash (BLA), was assessed for its ability in improving soil strength, reducing permeability, and enhancing durability. Soil samples were collected from water-logged areas and classified using standard geotechnical tests. These soils fell under the category of high-plasticity clays or silts, which are prone to swelling, shrinkage, and settlement. Bamboo leaves were collected from a local source market. The bamboo ash was mixed with soil in varying proportions of 2%, 4%, 6%, 8%, and 10% by weight. The mixture was thoroughly blended and compacted using standard procedures. Tests that were carried out include Atterberg Limits test to assess changes in plasticity and consistency; compaction tests to determine optimum moisture content (OMC) and maximum dry density (MDD); and California Bearing Ratio to evaluate load-bearing capacity. The results showed that bamboo ash significantly increases shear strength, especially at an optimal content of around 4% to 6%; the plasticity index decreases, indicating better dimensional stability and reduced swelling/shrinkage behavior; and CBR values improved, making the soil more suitable for subgrade and foundation applications.

This study aims to investigate the potential of using pulverized glass as a partial substitute for fine aggregate in concrete, focusing on how it affects the mechanical properties of the resulting composite. By exploring various replacement levels of pulverized glass, the project identified an optimal balance that enhances both the sustainability and performance of concrete. An experimental work was performed to study the slump, unit weight, compressive strength, dry density and water absorption of concrete partially substituted with pulverized glass. A concrete mix with a target mean strength of 20N/mm² was designed using a standard 1:2:4 mix ratio. Pulverized glass was used to partially replace the fine aggregate at replacement percentages of 0%, 5%, 10%, and 15% in accordance to relevant literature. The concrete was then cast into cubes and allowed to cure for 7, 14, and 28 days at room temperature in a laboratory. The results indicate that workability increases with higher pulverized glass content, with slump values rising from 30 mm for the control mix to 46 mm at 15% replacement. However, compressive strength generally decreased as the replacement percentage increased. The 5% replacement mix achieved the highest compressive strength among the modified mixes, with an average 28-day strength of 19.72 N/mm² compared to 20.68 N/mm² for the control mix. Nine concrete mixes were examined using discarded glass in place of 0%, 5%, and 15% of the weight of sand. The study concludes that, crushed glass can substitute up to 5% of fine aggregate in concrete, which helps lessen the effects of sand mining. This concrete can be regarded as eco-friendly since it uses less raw materials and has fewer negative environmental effects.

Water-logged soils are a persistent challenge in geotechnical engineering, especially in tropical regions where high rainfall and poor drainage lead to saturated ground conditions. These soils typically exhibit low shear strength, high compressibility, and Poor loadbearing capacity, making them unsuitable for construction without prior treatment. In this study bamboo ash especially bamboo leaf ash (BLA) was assessed for its ability in improving soil strength, reducing permeability, and enhancing durability. Soil samples were collected from water-logged areas and classified using standard geotechnical tests. These soils fell under the category of high-plasticity clays or silts, which are prone to swelling, shrinkage, and settlement. Bamboo leaves were collected from a local source market. The bamboo ash was mixed with soil in varying proportions 2%, 4%, 6%, 8%, and 10% by weight. The mixture was thoroughly blended and compacted using standard procedures. Test that were carried out include; Atterberg Limits test to assess changes in plasticity and consistency; Compaction; tests to determine optimum moisture content (OMC) and maximum dry density (MDD); California Bearing Ratio (CBR) to evaluate load-bearing capacity. The results showed that bamboo ash significantly increases shear strength,especially at an optimal content of around 4% to 6%, The plasticity index decreases, indicating better dimensional stability and reduced swelling/shrinkage behavior; CBR values improved, making the soil more suitable for subgrade and foundation applications.