DEPARTMENT OF CIVIL ENGINEERING,

This study assesses the critical influence of environmental and human-related factors on air pollutant concentrations across five major urban centers in Benin City, specifically comparing city centers with their adjacent public transport parks. Urban environments characterized by high human traffic density, stationary or slow-moving commercial vehicles, and concentrated emissions have raised serious concerns about ambient air quality and its resulting health impacts. Hence, this research aimed to localize the understanding of air quality dynamics in these environments. Portable air quality sensors were deployed to measure key criteria pollutants including Fine Particulate matter (PM₂.₅), Coarse Particulate matter (PM₁₀), Carbon monoxide (CO), Ground-level Ozone (O₃), and Volatile Organic Compounds (VOCs), alongside meteorological factors like relative humidity and temperature. Data was collected at varying periods and days to capture temporal variations and observe trends associated with human activities and traffic conditions. The outcome of the analysis revealed that Particulate Matter is the dominant air quality challenge, with all ten monitored sites recording dangerously high levels. Average concentrations of PM₂.₅ across the sites ranged from 57.0 µg/m³ in the City Center locations to 100.4 µg/m³ in the Motor Parks, demonstrating that all areas significantly exceed the 24-hour
guidelines set by both the WHO and NESREA. Motor parks consistently served as acute pollution hotspots, exhibiting PM concentrations between 40 and 76 percent higher than their city center counterparts. The most critical finding was at Oluku Motor Park, which recorded the highest average PM₁₀ concentration at 154.6 µg/m³, placing it in direct violation of the national standard. This extreme localized pollution is driven by vehicle exhaust, which is reflected in Carbon Monoxide levels that were consistently 87 percent to 142 percent higher in the motor parks compared to the city centers. The Air Quality Index (AQI) classification for all locations was determined to be "Unhealthy" or "Very Unhealthy". Overall, this research provides essential data that underscores the immediate need for improved public health protection and informed urban planning strategies aimed at mitigating vehicle-sourced pollution in these high-exposure zones.

Pedestrian bridges are essential components of urban transportation systems, yet their structural safety is significantly threatened when exposed to fire hazards. Recent incidents and limited available research on the fire performance of pedestrian bridge girders have highlighted the need for systematic research into their thermal response and post-fire behavior. This study was therefore conducted to examine the temperature distribution, degradation patterns, and fire endurance of three common girder types; steel I-beams, concrete I-beams, and concrete rectangular sections; together with a real-world evaluation of the composite girder used in the University of Benin pedestrian bridge. The overall aim was to understand how these girder systems behave under fire exposure. A finite element modelling (FEM) framework was developed using Abaqus CAE, employing transient thermal analysis under the ISO 834 standard fire curve. Temperature-dependent material properties were defined according to Eurocode 2 and 3 provisions, and 2Dthermal models of each girder section were created for computational efficiency. Boundary conditions included convection and radiation on fire-exposed surfaces, with analysis conducted at 1200s, 2400 s, and 3600 s to capture progressive heat penetration. For the University of Benin case study, a composite girder was modelled to evaluate real structural behavior under elevated temperatures, focusing on heat migration, cracking zones, and the thermal protection offered by the concrete slab. Results showed that steel I-beams heated rapidly and reached critical temperatures earliest
due to high thermal conductivity, resulting in rapid loss of stiffness and structural stability. Concrete I-beams demonstrated moderate resistance, while rectangular concrete beams performed best, maintaining a cool core even at long exposure times. The composite girder exhibited heat concentration along its underside, with spalling and reinforcement weakening in exposed regions but retained strength in upper concrete zones.

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.

Solid waste management remains a critical environmental and public health challenge within university environments, especially in residential staff quarters where large quantities of solid waste are generated on a daily basis but there is lack of proper management practices. Hence this study aims investigate the solid waste management practices in the junior staff quarters located within the University of Benin. The study employed quantification and characterization of household waste at the point of generation, collection of data with the aid of structured questionnaires and an observational checklist. Data were collected from the residents of the junior staff quarters over a seven day period to determine the rate and composition of waste generation among the residents of the staff quarters. Descriptive statistical tools were used to analyze the data obtained from the questionnaires. A pilot test and a reliability test using Cronbach’s alpha was also conducted to validate the clarity of the questionnaire items and to ensure the internal consistency and dependability of the questionnaire.Results obtained from the questionnaire showed that waste disposal posed a major challenge in the university of Benin Junior Staff Quarters as 97% residents reported there was no waste point availability, 75% reported that the waste collection frequency was irregular and 78% of residents reported that they did not pra tice waste segregation in the junior staff quarters. Observational checklists revealed that solid waste generated by residents were stored in open containers and sack bags with frequent spillage and noncollection. Waste characterization further showed that organic waste constituted the largest
portion (64.64%), nylon constituting 12.98% plastic constituting 5.96% Miscellaeneous constituting 11.1% metal and paper constituting the lowest with 4.43% and 0.89%
respectively

Traffic flow analysis is a key aspect of transportation and highway engineering that focuses on understanding the interaction between road users (pedestrians, cyclist, and drivers) and infrastructure, with the goal of achieving efficient traffic movement and minimizing congestion. This study was conducted along Airport Road in Benin City, Edo State, Using the moving observer method developed by Wardrop and Charlesworth (1954). This method is a cost-effective approach for analyzing traffic characteristics such as speed, density, space headway, and time headway.The methodology involved on observer traveling along a selected highway section at a suitable speed while recording important parameters. These included the number of vehicles overtaking the observer, the number of vehicles overtaken by the observer, travel time in the direction of the traffic, and travel time against traffic. Data collection was lane-specific, covering both the speed lane and the service lane, and also accounted for vehicle composition. To capture variations in traffic conditions, data was collected under two scenarios: during a period when schools were in session and when they were not.The collected data was analyzed using the Greenshield model, which assumes a linear relationship between speed and density. Results indicated that traffic flow on Airport Road falls under medium traffic volume range. The average time headway ranged from 3.07 to 3.89 seconds, while the average space headway varied between 0.035km and 0.042km. Maximum traffic capacity was found to range between 1064 veh/hr and 1505 veh/hr, with free-flow speeds between 53.01km/hr and 119.27km/hr. Jam density values from 43veh/hr to 102 veh/km. The coefficient of determination (𝑅2) values ranged from 0.365 to 0.844, confirming a strong positive linear relationship between speed and density, consistent with Greenshields model. This study also highlighted the significant impact of vehicular heterogeneity on traffic flow, particularly in the service lane where speeds were lower and density higher. In conclusion, the finding emphasizes that variations in vehicle types and driver’s behaviour significantly influence traffic flow characteristics and highway capacity. A proper understanding of these parameters is essential for effective traffic management, and informed policy-making to enhance mobility and safety on multi-lane highways in Benin City and similar urban environments.