DEPARTMENT OF CIVIL ENGINEERING

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.

In many developing countries, the high rate of building collapses is a constant concern. It raises important questions about construction practices, enforcement of regulations, and the integrity of professionals. Lagos State, one of Nigeria’s fastest-growing urban centres, has seen a troubling trend of structural failures in residential, commercial, and institutional buildings. These collapses often lead to unnecessary deaths, property loss, and economic disruption, showing deeper problems within the built environment. Despite more awareness and media coverage, the issue remains unresolved. Commonly cited reasons for building collapses include poor structural design, low-quality materials, lack of supervision, failure to follow building codes, and corruption in regulatory bodies. Yet, while these factors are often discussed, there is little clarity on which ones have the greatest impact on collapse events. This lack of prioritization makes it hard for stakeholders to focus their efforts, implement changes, or take precise preventive measures. Understanding the importance of each contributing factor is key to effectively addressing the problem. Not all causes are equally significant, and treating them as such may weaken the effectiveness of proposed solutions. There is a need for a structured approach to assess and rank these factors, especially in high-risk areas like Lagos State, where construction is both dense and fast-paced. Without this analysis, the cycle of collapse and reactive responses will likely continue

The alarming rate of road traffic accident in the country (Nigeria) is among the most worrisome problems currently facing the nation. Sadly, Nigeria has earned the unenviable distinction of consistently leading all the nations of the world in high road traffic accident and high fatality rate. One of the best ways to understand the occurrence of road accident is to develop accident prediction models which are also standard practices in assessing and improving the safety of our roads. The aim of this study is to conduct a comprehensive evaluation of selected expert systems such as multiple linear regression and artificial neural
network for the modelling and prediction of road accident. The study area is Ugbowo-Lagos Road. A reconnaissance survey was done first to ascertain the geometric characteristic of the road which include; the chainage, the vertical and horizontal curve and the super elevation. Thereafter, secondary data which include road accident data was collected from Federal Road Safety Office at lucky way Benin City. To investigate the qualities of the secondary data, basic preliminary analysis techniques, namely;
outlier detection, homogeneity test, test of normality and autocorrelation test were done. While modelling and prediction of road accident was done with the aid of multiple linear regression and artificial neural networks. From the geometric characteristic of the road under study, it was observed that for a chainage of 11.5 to 13km, the vertical curve was 12.4% while the super elevation was 4.3%. Calculated Cronbach alpha value of 0.900 as observed in the reliability test revealed that the data are reliable and the computed goodness of fit statistics of reliability gave a maximum Guttman coefficient of 88.10% which further confirm the reliability of the data used. With a computed p-value greater than 0.05 for all the independent variables, the null hypothesis of the Dixon test was accepted and it was concluded that the accident data obtained from FRSC is devoid of outliers. In addition, with a centered VIF(Vehicle influence factor) < 10, it was concluded that there is the absence of multicollinearity between the dependent (NAC) and independent variables (NPIV, NPIJ, NPK, NVI). With a computed coefficient of determination (R 2) value of 0.9265, artificial neural network (ANN) was acclaimed better road accident prediction model compare to multiple linear regression model (MLRM) with a computed R2 value of 0.0617. The implication of this findings states that if the R2 value is
lesser than 0.0617 it is will not to work .

The project titled “The effect of admixtures on properties of concrete: case study of sugar cane shaft ash, cow bone ash, groundnut shell ash,” will be carried out with the aim of knowing the effect the of the various types of admixtures used on the properties of concrete, in term of the workability of concrete, durability of concrete and the concrete strength. The material used are cow bone ash, groundnut shell ash, sugar cane shaft ash. The cow bone will be sourced along new Benin market, Edo state and the groundnut shell will be sourced from uselu market. The cow bone will be sun dried after careful separation from flesh, tissues and fats, the ash will be carried out by incinerating the bone at a temperature of 900⁰C in a furnace. Also, the groundnut shell ash will be obtained by burning groundnut shell on an iron sheet in the open air under normal temperature while sugar cane shaft ash. The method adopted will be; batching of concrete materials, mixing of concrete materials, production of cubes, curing of cubes (for 7days, 14days and 28days) while the test carried out during and after the concrete cubes are produced or casted are; sieve analysis test, slump test and compressive strength test. From the sieve analysis test carried out on both fine and coarse aggregates, it will be discovered that the coefficient of uniformity (Cu) obtained are less than 4, hence they are both “well-graded” aggregates. The slump test shows that there is increase in the slump value from sugar cane shaft ash-concrete, GSA-concrete, CBA-concrete and LP-concrete, likewise the compressive strength test increases from sugar cane shaft ash-concrete, GSA-concrete, CBA-concrete and LP-concrete. From the findings, it is evident that the combination of the three admixtures resulted in the highest percentage increase in compressive strength. Additionally, the average maximum strength was achieved when the fine aggregate was replaced by 15% with the admixture. Despite variations in replacement percentages, all samples exhibited compressive strengths that align with the expected design characteristics of concrete, particularly around the target value of 20 KN/mm². The sieve analysis further revealed a well-graded particle size distribution in the fine aggregate samples, indicating suitability for achieving optimal concrete mix designs.

The project titled “Experimental Study on the Partial Replacement of Fine Aggregates with Plastic in the Production of Concretes,” was carried out with the aim of knowing the effect of partially replacing fine aggregates with plastic waste in concrete production. The aim is twofold: to mitigate environmental impact by repurposing plastic waste and to evaluate the performance of plastic-aggregate concrete. Methodologically, various types of plastic waste are selected and processed to suitable sizes for incorporation into concrete mixes. Comprehensive testing is conducted to assess both the fresh and hardened properties of the resulting concrete specimens. Tests include workability assessments using slump tests, as well as mechanical property evaluations such as compressive tests. The spent plastics were gathered, ground into smaller components, pulverized in order to get granules of plastic lower than 4.75mm size. Sieve studies were carried out for particle size distribution. 9 nos. of 10cm x10cm x10 cm cement concrete Cubes of 1:1.5:3 (C25) mix were cast for 0%, 5%, 10%, 15%, sand being substituted by Pulverized plastic material. Volumetric proportioning was utilized instead of design mix since the density of plastic material was too low. Workability test, weight and compressive strength of the cubes were determined. The results of the study shows that the slump of the fresh concrete decreased with increase in the replacement of the fine aggregate. This implies that the presence of plastic in the concrete decreased its workability. Also, the control sample, with no replacement, exhibited the highest compressive strength throughout the curing periods of 7, 14, and 28 days. As the percentage of sand replacement increased, there was a noticeable decrease in compressive strength. Notably, the replacement of 5% of sand with plastic material showed a gradual decrease, while beyond 10%, the decrease became more significant. This trend is attributed to the inability of plastic waste aggregate to effectively interact with the cement paste, unlike natural aggregate. Recycling of plastic trash with river sand decreases its negative environmental impact of river sand quarries, reduces the depletion of natural resources Based on the findings of this study, it can be concluded that the replacement of natural sand with plastic waste aggregate in concrete production leads to a reduction in compressive strength. However, the similarity in particle distribution between natural sand and plastic material suggests the potential for utilizing plastic waste as a partial replacement for sand without significant compromise in textural properties.