DEPARTMENT OF CIVIL ENGINEERING

This research investigated the utilization of polypropylene (PP) waste as an additive in the production of sandcrete blocks, aimed at promoting sustainable waste management and reducing the environmental impact of plastic pollution. The study sought to determine the influence of varying polypropylene waste contents on the physical and mechanical properties of sandcrete blocks, thereby evaluating its suitability as a construction material modifier. The experimental work involved producing paving stone specimens with 0%, 1%, 2%, 3% and 4% polypropylene waste by weight of sand. Aggregates were first characterized through specific gravity and sieve analysis to ensure conformity with standard specifications. Sandcrete blocks were then cast, cured in water, and tested for water absorption and compressive strength at 3 and 7 days of curing, following procedures outlined in relevant British Standards. This methodology ensured uniformity in mixing, curing and testing, allowing a clear assessment of polypropylene’s effect on the samples’ performance. The results showed the polypropylene addition influenced both durability and strength properties. Water absorption ranged between 0.64% and 2.88% with the lowest value recorded at 4% PP content, suggesting improved impermeability at higher plastic dosages. Compressive strength ranged from 11.41Mpa and 16.07Mpa, with optimum strength achieved at 1% PP addition, after which a gradual reduction is observed. It was concluded that the inclusion of polypropylene waste up to 1% can enhance strength and durability without compromising structural performance. The study recommends using low dosages of polypropylene waste in sandcrete blocks production and encourages further research into improving interfacial bonding through surface modification and longer curing periods to
maximize the material’s potential for sustainable construction.

Climate change poses significant threats to the built environment through rising temperatures, altered precipitation patterns, and increased frequency of extreme weather events. This study investigated the impact of climate change on the durability of building materials commonly used in Nigeria. A comprehensive analysis of 60 years of meteorological data (1965-2024) from the Nigerian Meteorological Agency (NIMET) was conducted across Nigeria's three climatic zones. The data was divided into two 30-year periods Historical Period 1 (HP1: 1965-1994) and Historical Period 2 (HP2: 1995-2024) to identify climatic trends and their implications for concrete, steel, timber, and masonry materials. The methodology employed secondary data collection and literature review, analyzing four key climatic parameters: mean annual temperature, total annual rainfall, mean annual sunshine hours, and mean annual wind speed. Comparative analysis revealed significant environmental shifts, with Southern Nigeria experiencing the most severe changes including temperature increases of +1.0°C, rainfall increases of +298mm, and reductions in both sunshine hours (-0.6 hr/day) and wind speed (-0.6 m/s).Results demonstrated that all building materials face substantially accelerated degradation under current conditions. Concrete experiences enhanced carbonation and chloride penetration with 2030% service life reductions. Steel reinforcement shows 30-40% service life reduction in coastal environments due to intensified corrosion. Timber faces the highest vulnerability with potential 40-50% service life reductions from enhanced fungal decay and increased termite activity. Porous masonry units experience severe efflorescence and progressive strength loss, resulting in 20-40% service life reductions. The study revealed synergistic effects where combined climatic changes produce deterioration exceeding individual impacts, with Southern Nigeria facing the most aggressive conditions. The study concludes that traditional construction practices based on historical climate data are inadequate for current conditions. Recommendations include immediate revision of building codes and material specifications, adoption of climate-resilient materials and enhanced protective systems, implementation of climate-responsive design approaches, and intensified maintenance programs for existing structures. These findings provide critical insights for stakeholders to enhance building resilience and ensure the sustainability and safety of Nigeria's built environment.

This study assessed the water quality of the fish pond located at the Faculty of Agriculture, University of Benin, with the aim of determining its Water Quality Index (WQI) and proposing environmentally sustainable alternative uses in the event of water exchange or discharge. The study was carried out in response to the growing need for scientific evaluation of aquaculture effluents, which, if improperly managed, may cause ecological degradation through nutrient enrichment, heavy metal buildup, and microbial contamination. The research therefore sought to evaluate the physicochemical and microbial characteristics of the pond water, compute its WQI using the Arithmetic Weightage Index Model, and recommend safe reuse or disposal options. Water samples were collected from two ponds (Sample A and Sample B) representing five-day and thirteen-day retention periods respectively. Laboratory analyses were performed in the Civil Engineering Hydraulics/Water Laboratory following APHA (2017) standard methods to determine parameters such as pH, turbidity, total dissolved solids (TDS), total suspended solids (TSS), etc. The obtained data were analyzed using the Arithmetic Weightage Index Model, where individual parameter values were compared against WHO (2017) and FAO (2011) standards to derive the overall WQI and corresponding water quality grades The results showed that Sample A, with a WQI of 20.41, was classified as Excellent, indicating that the pond water met acceptable limits. Sample B, with a WQI of 51.69, fell under the Poor category, signifying moderate pollution resulting from prolonged water retention, organic enrichment, and higher microbial counts. Consequently, while Sample A water could be reused or safely discharged without treatment, Sample B water required simple treatment such as aeration or sedimentation prior to reuse or discharge. The study concluded that proper monitoring of water quality and periodic application of the WQI approach are vital for sustainable aquaculture management. It recommended regular effluent testing, adoption of low cost pre-treatment systems, and reuse of treated pond water for agricultural irrigation or secondary aquaculture to reduce environmental pollution and promote resource conservation.

The project addresses the growing concern of gully erosion in regions like Benin City, Nigeria, where intense rainfall and poor land management have caused severe soil degradation, loss of agricultural land, and infrastructure damage. Traditional erosion control methods have often been costly, rigid, and unsustainable. This study introduces gabion retaining structures as a flexible, cost-effective, and environmentally friendly alternative. Gabions, which are wire mesh baskets filled with stones, offer the ability to withstand flowing water and adapt to unstable ground while promoting soil stability and water conservation. The study involves evaluating the performance of gabion structures in mitigating gully erosion in a specific location Federal College Road, Benin City. Site reconnaissance to identify critical erosion-prone areas was done. Hydrological analysis using the Rational Formula estimate streamflow was carried out whilst designing, assembling, and installation of gabion baskets in affected zone was done with key design considerations including appropriate stone size, mesh type (Type 60: 60×80 mm), and structural layout. The performance of the gabions was assessed through regular visual inspections for deformation and settlement. The project demonstrated that gabion structures are a sustainable and practical solution for controlling minor gully erosion. Results showed improved soil stability and there was a clear reduction in both the depth and speed of water flow from 0.71 m to 0.52 m in depth and from1.54 m/s to 1.39 m/s in speed helping to stabilize the gully and prevent further soil loss. Additionally, the structure was able to withstand environmental stresses without major maintenance, offering a scalable model for other erosion-prone regions. This result provides useful insights for engineers, policymakers, and local communities seeking cost-effective solutions for land protection and sustainable infrastructure.

This study investigated the effect of partially replacing Ordinary Portland Cement (OPC) with eggshell powder (ESP) in concrete production as a sustainable approach to reduce cement consumption and utilize agricultural waste. The aim of the study was to evaluate the performance of concrete containing eggshell powder as a partial replacement for cement. The specific objectives were to determine the workability of concrete containing varying proportions of ESP, evaluate its compressive strength, assess its water absorption capacity as an indicator of durability, and identify the optimal ESP replacement level that yields the best concrete performance. The experimental study was conducted by preparing concrete mixes with 0%, 5%, 10%, 15%, and 20% replacement of cement with eggshell powder. Waste eggshells were collected, cleaned, dried, ground into fine powder, and sieved before use. Concrete cubes were cast and cured in water, after which several laboratory tests were performed. Workability of the fresh concrete was determined using the slump test, compressive strength was measured at 7, 14, and 28 days using a compression testing machine, and water absorption tests were carried out at 28 days to evaluate the durability-related properties of the hardened concrete.The results showed that workability slightly increased at 5% ESP replacement, indicating improved particle packing within the mix, but gradually decreased at higher replacement levels due to increased water demand of the fine ESP particles. The compressive strength of the concrete improved at moderate replacement levels, with the optimum strength obtained at 15% ESP replacement after 28 days of curing, while further increase in ESP content led to a reduction in strength. The water absorption values for all concrete mixes were below 10%, indicating that the inclusion of ESP did not adversely affect the durability of the concrete. Based on the findings, the study concluded that eggshell powder can effectively replace cement up to 15% without significantly compromising the essential properties of concrete. It is therefore recommended that ESP be considered as a sustainable partial cement replacement material in concrete production, particularly for applications such as pavements, floor screeds, and foundations, where environmentally friendly and cost-effective construction materials are desirable

This study investigated the effect of nanosilica (NS) as a partial replacement for ordinary Portland cement (OPC) on the mechanical and durability properties of concrete. The aim was to assess the suitability of nanosilica in improving concrete performance and to determine its optimum replacement level for sustainable construction applications in Nigeria.Concrete was produced using a nominal mix ratio of 1:2:4 and a constant water–cement ratio of 0.5. Nanosilica was used to replace cement at levels of 0%, 1%, 2%, and 3% by weight. Tests carried out included slump test, setting time determination, compressive strength test, flexural strength test, and water absorption test. Statistical analysis of the results was performed using oneway analysis of variance (ANOVA).Results showed that workability increased with increasing nanosilica content, while both initial and final setting times decreased. Compressive and flexural strengths increased up to an optimum nanosilica content of 2%, where 28-day values of 24.4 N/mm² and 5.25 N/mm² were recorded, compared to 22.5 N/mm² and 4.67 N/mm² for the control mix. Water absorption reduced to 7.3% at 2% nanosilica replacement compared to 9.7% for the control, indicating improved durability. ANOVA results showed no significant differences in compressive strength, flexural strength, and workability (p > 0.05), while setting time showed significant variation (p < 0.05). The study concluded that 2% nanosilica replacement provided the best overall performance and is recommended for producing stronger and more durable concrete

In this study, Remote Sensing (RS), Land-sat 8 digital data, and digital elevation models
(DEMs) from the Advanced Space-borne Thermal Emission and Reflection Radiometer
(ASTER), Food and Agricultural Organization (FAO) along with other stereotypical data
such as geology and rainfall were digitized and analyzed to create various thematic maps
(geology, land use/cover, soil, drainage density, rainfall and slope maps) required for
groundwater modelling in the study area. These thematic maps were assigned well-chosen weights and different rankings to the individual categories within each thematic map using a manual Analytical Hierarchy Process (AHP). Parameters which had high influence on groundwater potential assessment were given higher percentages based on some criteria and others were which had low impact given low percentages. The groundwater potential zones are achieved by overlaying the thematic maps using the spatial analysis tool in Arc-GIS 10.8.

In our pursuit of sustainable solutions to address environmental challenges, the treatment and reuse of wastewater have gained significant attention. The automobile industry, renowned for its substantial water consumption and discharge, has emerged as a focal point for exploring innovative approaches to wastewater management. This study investigates the potential applications, benefits, and challenges associated with utilizing automobile wastewater in construction activities. The scope of work involved collecting samples from car wash facilities, analyzing chemical and mineral properties, preparing concrete mixes, and conducting tests using both potable water and automobile wastewater. Laboratory tests on the automobile wastewater samples demonstrated that key parameters such as Total Dissolved Solids (TDS), chloride (Cl⁻), bicarbonate (HCO₃), and sulfate (SO₄) were within standard limits for concrete production. Notably, the setting time tests on cement molds revealed a significant 27.73% reduction in initial setting time and a 14.81% increase in final setting time using first wash compared to potable water. The use of second wash resulted in a more substantial 45.38% decrease in initial setting time and a modest 3.70% increase in final setting time. Slump tests correlated detergent concentration with higher values for the first wash. However, the compression tests on concrete indicated a decrease in strength, with a 35.96% reduction at 28 days against first wash and a more significant 54.75% reduction against second wash. In conclusion it is evident that for automobile waste water to be used for concrete production, it must undergo process of treatment. As recommendation, it is advised to implement effective treatment processes for automobile wastewater before incorporating it into concrete production, ensuring that the construction materials meet required standards and contribute to sustainable environmental practices in the automobile industry.

Hydraulic structures such as dams require energy dissipation for their safe operation. Scouring and cavitation are challenges which may arise at the downstream toe of earth dams due to inadequate provision for proper energy dissipation leading to severe damages or total loss of the dam. This study aimed at designing the United States Bureau of Reclamation (USBR) type III basin for energy dissipation downstream of earth dam spillways in Nigeria using Microsoft Excel as computational tool. Microsoft Excel was used in developing the design code governed by a set of algorithms which conformed to USBR standard. The algorithm was used to compute flow data suitable for the formation of hydraulic jump within the USBR type III stilling basin. Various flow conditions with discharges ranging from 10 m3 /s to 110 m3 /s and inflow velocity ranging from 3 m/s to 18 m/s) were simulated at various basin widths ranging from 3 m to 12 m. Acceptable design flows were determined using the Froude numbers that ranged between 4.5 to 9 as the major criterion. The results obtained showed that an increase in velocity led to an increased Froude number for the various basinm widths. At 3 m/s inflow velocity, the mean Fr values were 0.59, 0.85, 1.03 and 1.10 forstilling basins width of 3 m, 6 m, 9 m and 12 m respectively. At 6 m/s the mean Fr valueswere 1.69, 2.38, 2.93 and 3.38. At 9 m/s, mean Fr values were 3.10, 4.34, 5.37 and 6.21. At 12 m/s, the mean Fr values were 4.77, 6.76, 8.82 and 9.47. At 15 m/s, mean Fr values were 6.68, 9.89, 9.89 and 13.36. At 18 m/s mean Fr values were 8.68, 12.42, 15.22 and 17.57. These implied that at increased basin widths, the efficiency of the formation of hydraulic jump improved with higher inflow velocities resulting in shorter basins with more numbers of baffle piers and chute blocks. The results obtained will find relevant application in the preliminary design of the type III stilling basins for earth dams, reservoirs in Nigeria, in accordance with the United States Bureau of Reclamation standard. It will also aid Engineers in the proper control and evacuation of small earth dams while checking erosive effects from the velocity of the evacuated outflow by means of hydraulic jump formation. Furthermore, experimental researches involving physical models are recommended to ascertain more results and facilitate more efficient and economical USBR stillingbasin designs

This study aimed to develop and validate a hybrid analytical framework for the structural analysis of orthotropic steel bridge decks, particularly those with skewed or curved geometries. The primary goal was to improve the accuracy of load distribution and force prediction by integrating the classical Morrice and Little (M-L) design curve method with a finite-element orthotropic-plate model within a MATLAB environment. The study was motivated by the need to reduce the limitations of purely empirical approaches and the computational burden of full-scale 3D finite element (FE) analysis, offering an efficient yet accurate alternative for early and intermediate stages of bridge design.
The methodology involved extracting detailed geometric and material data from a 30 m long, simply supported orthotropic bridge deck modelled in STAADPro v8i, including 3 main girders (W900 × 300 mm), 12 mm thick longitudinal ribs spaced at 300 mm, and 2 m cross-girder spacing. Flexural rigidities (Dx, Dy), torsional constant (α = 0.45), and skew factor (θ = 0.789) were calculated and used in a finite-difference orthotropic plate model (1 m × 1 m mesh with simply supported boundaries). Load effects from a 300 kN HB axle (with a 1.25 impact factor) were applied at mid-span. MATLAB was used to interpolate M-L distribution coefficients, integrate them with global stiffness matrices, and perform moment and deflection analysis. Comparative validation was performed against detailed shell-element results from STAADPro.
Numerical results showed that the hybrid model predicted peak girder bending moments of 5951KNm, closely matching the STAADPro value of 5850KNm, with an error margin of just 1.7%. The mid-span deflection was 19.4 mm, only 2.6% higher than the STAAD result (18.9 mm), and well within the L/500 deflection limit of 60 mm. In contrast, the classical M-L method predicted a more conservative moment of 5380KNm, 8% lower than STAAD. Computational efficiency was significantly improved: MATLAB solved each case in under 0.8 seconds, compared to 45 seconds per case in STAADPro, demonstrating a 50× speed-up. These findings confirmed that the hybrid approach offers a code-compliant, accurate, and computationally efficient solution for the analysis of orthotropic bridge decks, reducing over-design and enabling faster design cycles.