Civil & Environmental Engineering- Scholarly Publications
Permanent URI for this collection
Browse
Browsing Civil & Environmental Engineering- Scholarly Publications by Issue Date
Now showing 1 - 20 of 83
Results Per Page
Sort Options
- ItemOpen AccessHydrogeology of Lagos metropolis(Pergamons Journal Ltd, 1987) Longe, E.O.; Malomo, S.; Olorunniwo, M.A.A study of the groundwater resources and aquifers underlying Lagos metropolis has been made. This is based on well-logs, pumping tests, well-production and water quality data. The data were obtained during construction and use of recent boreholes of the Lagos State mini water works programme. The sub-surface geology indicates a complex lithology of alternating sequence of sand and clay deposits. Three aquifer horizons were delineated. The first, a water table aquifer (average thickness of 8 m) is mostly exploited through dug wells. The other two, confined aquifers (thicknesses of 10-25 and 10-35m respectively), are harnessed through boreholes and are the basis of the mini water works. Average values of transmissivity (T) and storage coefficients (S) are 3.53 x 10-3 m2 s-1 and 2.95 x 10-4 respectively for the second and 17.44 × 10-3 m2 s-1 and 3.29 x 10-4 for the third. The range of transmissivity, the storage coefficient and also permeability indicate considerable inhomogeneity in the aquifers. Chemical quality determinations show that the harnessed aquifers waters are generally soft. They are suitable for use in domestic, agricultural and industrial processes, if the excessive iron occurring is removed.
- ItemOpen AccessDetermination Of Some Structural Properties Of African Oil Palm Timber (ELAIES GUINEENSIS)(1989) Ajibola, K; Falade, FOil palm trees are abundant in Nigeria but they are hardly used for structural purposes, except in some rural areas where they are used as roof trusses, floor joists and occassionally columns.' In this paper tensile strength along the grain direction, compressive strength parallel and perpendicular to the grain direction and the bending strength are reported on The strength of the inner and outer core materials are compared. The results showed that the outer core of oil palm timber has higher strength than the inner core and that the strength of the palm is influenced by the closeness of the black strands. The highest recorded compressive strength parallel to the grain direction is 1.32 times- the strength perpendicular to the grain direction for the specimen taken from inner core and 2~37times for the specimen taken from peripheral.
- ItemOpen AccessTechniques of land treatment of domestic wastewater and protection of underground water resources(Nigeria Association of Hydrogeologists, 1989) Longe, E.O.; Brissaud, F; Joseph, CMany people both in developed and developing countries use septic tank systems as means of treating their domestic wastes. Pit latrine systems are much in use in many rural areas of the developing countries where, in most cases, water supplies are by dug wells. Domestic wastes contain dangerous substances and pathogenic microorganisms which are responsible for waterborne diseases. Land disposal and treatment systems of domestic wastes appear as the solution to disposal problems in developing countries. These techniques are relatively simple and could be well adapted in any system under appropriate environmental and hydrogeological conditions. Other advantages include relatively low capital and operating costs.
- ItemOpen AccessEffects Of Sawdust Ash On The Strength Of Laterized Concrete.(1990-01) Falade, F.The construction industry in Nigeria is presently operating at a low ebb due mainly to the high cost of construction materials. The use of local materials has been advocated as a step towards solving this problem. This paper considered the use of sawdust ash (SDA) as a partial replacement of cement in laterized concrete.Compressive strength tests of samples made from mix proportions 1:1.5: 3,1 :2:4 and 1:3:6 at various curing ages (7,14,21 and 28 days) for varying SDA content (0,5,10,15,20 and 25%) but at constant water/cement SDA ratio for each mix proportion were considered. It was found that the addition of SDA decreases the strength. The rate of gain of strength, however, was more rapid at curing ages of 21 and 28 days, especially in the mixtures with high percentages of SDA. Strength development was also found to be higher for mixes with lower aggregate/cement ratios than for those with higher ratios.
- ItemOpen AccessInfluence of Method and Duration of Curing and of Mix Proportions on Strength of Concrete Containing Laterite Fine Aggregate(1991 Pergamon Press PLC., 1991) Falade, F.This this paper, the influence of six curing methods (water, air, moist soil, jute bag, air/water and water/air) on the compressive strength of concrete cube specimens that contain laterite fine aggregate is investigated. Three different mixes of cement, laterite and gravel were used: I : 11: 3 ;I: 2: 4 and I : 3: 6 with water/cement ratios of 0.62, 0.75 and 1.02 by weight respectively. Four curing ages of 7, 14,21 and 28 days were adopted. The results showed that the strength that a particular mix can attain is affected by the curing method used. The water/air curing technique gave the highest strength values of28.2 Nmm: +for 1 : 11: 3; 23.9 Nmm: 2 and 17.4 Nmrn: 2 for I : 2: 4 and I : 3 : 6 mixes respectively, while the air-cured specimens gave the lowest strength values of 17.2 Nmm=i for I: 1~:3, 16.8 Nmmr ? and 8.0 Nmmr= for 1 :2:4 and I :3:6 mixes. The higher the cement/aggregate ratio the higher the strength. Generally, there was increase in strength with age irrespective of the mix and the curing technique.
- ItemOpen AccessBehaviour of Laterized Concrete Beams under Moment and Shear(1991) Falade, FThe science and technique of substituting laterite for fine aggregate ill normal concrete work is rapidly increasing ill Nigeria. Studies Oil laterized concrete elements have been devoted primarily to observation under unit actions like the cube strength, split tensile strength, modulus 0/ rupture and creep characteristics. The present report gives the results of twenty four reinforced-laterized concrete beams, they were tested under combined actions of moment and shear. The principal variable are the mix proportions, percentage tensile reinforcement and shear span 10 effective depth ratio (aid). The results showed that the higher the percentage tensile reinforcement and cement or aggregate ratio the higher the shear and moment capacities 0/ the beams. When the shear span to effective depth ratio was increased, the shear capacity of the beams decreased while moment capacity increased. The shear span to effective depth ratio is the single most important factor that influences the mode of failure of the laterited concrete beams.
- ItemOpen AccessBehaviour Laterized Concrete Beams Under Moment And Shear.(1991-02-21) Falade, F.Abstract: The science and technique of substituting laterite for fine aggregate ill normal concrete work is rapidly increasing ill Nigeria. Studies Oil laterized concrete elements have been devoted primarily to observation under unit actions like the cube strength, split tensile strength, modulus 0/ rupture and creep characteristics. The present report gives the results of twenty four reinforced-laterized concrete beams, they were tested under combined actions of moment and shear. The principal variable are the mix proportions, percentage tensile reinforcement and shear span 10 effective depth ratio (aid). The results showed that the higher the percentage tensile reinforcement and cement or aggregate ratio the higher the shear and moment capacities 0/ the beams. When the shear span to effective depth ratio was increased, the shear capacity of the beams decreased while moment capacity increased. The shear span to effective depth ratio is the single most important factor that influences the mode of failure of the laterited concrete beams
- ItemOpen AccessInfluence of Water/Cement Ratios and Mix Proportions on Workability and Characteristic Strength of Concrete Containing Laterite Fine Aggregate(Pergamon Press PLC., 1994) Falade, F.This paper examines the variation of work ability and characteristic strength of laterized concrete (concrete containing laterite fine aggregate instead of sand) with different water/cement ratios and mix proportions. Four mixes of cement : lateritic soil: crushed granite were considered, namely I: I : 2, I: 11: 3, I: 2 : 4 and I: 3 : 6. Two methods-slump and compacting factor tests were used for the workability while the conventional cube test was used for the compressive strength. Cubes (100 mm) were made, water-cured at 21 +2°C and tested at 7 and 28 days. The results showed that the water requirement for a mix increases with increase in laterite/cement ratio. Associated with slump test are: zero, true, partial collapse and collapse slumps. The strength decreases with increase in laterite/cement and water/cement ratios. It was further found that the workability decreases with increase in laterite/cement ratio. The results indicated that the well established variations of workability and compressive strength of normal concrete with water/cement ratios are valid for laterized concrete.
- ItemOpen AccessAn Investigation of Periwinkle Shells as Coarse Aggregate in Concrete(Elsevier Science Limited, 1995-10) Falade, FAn Investigation into using periwinkle shells (PWS) partially or wholly in concrete is reported. Three standard mixes of cement: sand: granite + PWS (1:Full-size image (<1 K):3, 1:2:4 and 1:3:6) and two design mixes of cement: sand: PWS (1:Full-size image (<1 K):1 and 1:Full-size image (<1 K): Full-size image (<1 K)) were used. The proportion of shells was varied at intervals of 10% in the standard mixes. Two strength properties (compressive and flexural) were considered. The variations of workability and density of the specimens with different proportions of PWS were also studied. Results showed that the compressive and flexural strengths decreased with increase in proportion of PWS to granite in the standard mixes. The 28th day strengths for the design mixes were 15.65 N/mm2 for 1:Full-size image (<1 K):1 and 11.77 N/mm2 for 1:Full-size image (<1 K):1 with corresponding densities of 2100 and 1850 kg/m3. The unit weight of PWS was found to be 694.44 kg/m3. This indicates that PWS is a lightweight aggregate. The workability of concrete batches decreased with increase in the proportion of PWS in the mixes. The same trend was observed with the densities of the concrete cubes. The density of concrete containing 100% PWS showed that the concrete produced is lightweight, giving strengths ranging from 11.77 to 15.65 N/mm2.
- ItemOpen AccessEffects Of Separation Of Grain Sizes Of Fine Aggregate On Properties Of Concrete Containing Granite Fines.(1999) Falade, F.In this study, seven grain size ranges of granite fines were used: 4.75 - 3.35mm, 3.35 - 2.36mm, 2.36 - 1.70mm, 1.70 - 1.18mm, 1.18 - 0.30mm, 0.30 - 0.063mm and 4.75 - 0.063mm (those containing all grain sizes). The properties considered for the investigation are compressive and flexural strengths, density and workability. Four mix proportions of cement, fine and coarse aggregates 1:11h: 3, 1:2:4, 1:3:6 and 1:0:3 (nofines) by weight were used in the tests. JOOmm cubes and 100 x 100 x 500mm beams were cast and cured in water at 21 ± 1°C. The specimens were tested at 7, 14, 21 and 28 days. The results showed that the compressive and flexural strengths and density increased with decreasing grain sizes, while the workability decreased with decrease in grain sizes.
- ItemOpen AccessEffects of Seperation of Grain Sizes of Fine Aggregate on Properties of Concrete Containing Granite Fines(1999) Falade, FIn this study, seven grain size ranges of granite fines were used: 4.75 - 3.35mm, 3.35 - 2.36mm, 2.36 - 1.70mm, 1.70 - 1.18mm, 1.18 - 0.30mm, 0.30 - 0.063mm and 4.75 - 0.063mm (those containing all grain sizes). The properties considered for the investigation are compressive and flexural strengths, density and workability. Four mix proportions of cement, fine and coarse aggregates 1:11h: 3, 1:2:4, 1:3:6 and 1:0:3 (nofines) by weight were used in the tests. JOOmm cubes and 100 x 100 x 500mm beams were cast and cured in water at 21 ± 1°C. The specimens were tested at 7, 14, 21 and 28 days. The results showed that the compressive and flexural strengths and density increased with decreasing grain sizes, while the workability decreased with decrease in grain sizes.
- ItemOpen AccessA Comparative Study of Normal Concrete With Concretes Containing Granite and Laterite Fine Aggregates(Elsevier Science Limited, 2001) Falade, FThree types of fine aggregates are investigated for making concrete. namely sand for normal concrete, granite and laterite fines. The properties considered are compressive and tensile strengths. Three mix proportions of cement. fine and coarse aggregates are used: I: 1.5:3. 1:2:4 and I :3:6 (cement: fine: coarse) with water/cement ratios of 0.62, 0.75 and 1.0 respectively. 100mrn cubes and 150 x 300mrn cylinders were prepared and cured in water at 21±lo C. The specimens were tested for each mix at curing ages of7, 14,21, and 28 days. The results showed that concrete containing granite fines has the highest strength values both in compression and tension while concrete made with laterite fines has the lowest strength. For all the samples the strength characteristics decreased with increase in aggregate/cement ratio but increased with age irrespective of type of fine aggregate and mix proportion. Generally, the tensile strength was found to vary from 10 -12% of the compression strength values for 1:1.5:3 and 1:2:4 mixes and it was about 15% for I :3:6 mix.
- ItemOpen AccessBehaviour And Analysis Of Bamboo Reinforced Concrete Beams Under Flexural Loading.(2002) Falade, F.; Akeju, T.A.I.In this study, the behaviour of bamboo reinforced concrete beams was examined under a third point loading. Each beam was simply supported over an effective span of 600mm. The results showed that the behaviour of the beams was governed by the strengths, moduli of elasticity and stress-strain relationship of its components (reinforcement and concrete). Bamboo reinforced beams exhibited enhanced cracking and failure strengths when compared to the equivalent in plain concrete. There was increase in first-cracking and post-cracking strengths for beams with increase in bamboo content and curing age. A comparison of stress-strain distribution in the beam at different percentages of reinforcement indicates an optimum of 5.20% of cross sectional area of the beam for bamboo in bamboo reinforced concrete beams.
- ItemOpen AccessIndustrial Training as an Integral of Engineering and Technology Education: Issues and Prospects(2002-09-23) Falade, FIn this paper, the philosophy of engineering and technology education curricula in Nigerian Universities is presented. The paper notes that in formulating the curricula, industrial training is incorporated into the programme to ensure that students are given the much needed on-job-experience during their course of study in the Universities, to make them better prepared for the challenges in the industry thus making them more relevant in the industry after graduation. An assessment is made of how well the curricula have been able to meet the needs of the industry taking cognisance of all the obstacles militating against the effective performance of Faculties of Engineering and Technology in the Universities and the problems in the industrial sector. It is suggested that to make progress technologically, there need to provide an enabling environment that guarantees adequate facilities and funding engineering and technology education in the universities and corresponding expansion in the industry.
- ItemOpen AccessAfrican Regional Conference on Engineering Education:(2004) Falade, F.The African Regional Conference on Engineering Education (ARCEE) provides a forum for all the stakeholders in engineering and technology education within the region to come together and deliberate on common problems within the compass of engineering and technology and proffering solutions to them. We have had two meetings in Lagos, Nigeria (2002 and 2004). During ARCEE 2002, it was decided that the programme be held biennially and to be rotated among the member nations while in 2004 an action plan was drawn up and strategies were mapped out for its implementation. The details of the action plan are presented in this paper. The third meeting tagged 'ARCEE 2006' is to be held in Pretoria, South Africa.
- ItemOpen AccessA study on the Properties of Fibre Reinforced Laterized Concretes(2006) Ikponmwosa*, E; Falade, FThis paper reports on a study of strength properties of fibre reinforced laterized concretes. The variables in this experimental work are: laterite content in the concrete mix, which was varied from 0% to 100% at 10% interval; curing ages - 7, 14, 21 and 28 days. The concrete mix of 1:2:4 (Cement: Laterite/Sand: Granite) was used with a constant water/cement ratio of 0.65. The fibre content was kept at 2% at all replacement levels with 0% fibre content as control experiment. Three (3) 150mm cube specimens were cast and tested for each mix of concrete with laterite content varied at 10% at the curing ages of 7, 14, 21 and 28 days. The specimens were cured in water at temperature of 21°± 1°C. . . The average load at which a set of three specimens failed was determined and used to compute the strength of each group of cubes. A consistent trend of increase in values of strength with age was observed in the specimens. A proportion of 45% laterite content as replacement of sharp sand in concrete produced the highest compressive strength. At 45% laterite content, a reduction of 18% in cost of fine aggregate in concrete was obtained. Although the strength characteristic of laterized concrete was found to be generally lower than that of normal concrete, notwithstanding, the strength is sufficient for use in normal concrete works.
- ItemOpen AccessEngineering and Globalisation in Developing Countries:(2006-09-27) Falade, F.This paper examines the role of engineering in the context of national development and takes a look at it globally. Globalisation can be said to mean the well-accepted objectives of engineering education, which are not defined by national views only but by worldwide scope of the development of engineering and technology. The implications of globalisation to developing countries are highlighted while its associated problems and sustainability in the third world countries are discussed. The paper notes that some changes are required in Nigeria for her quest to launch into the global trend and such participation should take cognisance of national development.
- ItemOpen AccessScope of Bamboo Reinforcement in Concrete Beams For Low- Cost Housing.(Nigerian Building And Road Research Institute (NBRRI)., 2006-12) Falade, F.; Ikponmwosa, E.This paper investigates the extent to which bamboo reinforcement can be used in concrete beams for low-cost housing. Beams of uniform cross sectional area (225x450mm) were designed to BS 8110. They were simply supported over varying effective spans of 3.0, 3.5, 4.0 and 4.5 metres. The results of the laboratory tests showed that the average 28-day characteristic strength of concrete was 25N/mm2 while an average tensile strength of 133.50N/mm2 was obtained for bamboo splints of size 10x10mm (square section). The design was based on two limit states: ultimate and serviceability (deflection). The beams were subjected to 20%, 40%, 60%, 80% and 100% of the ultimate moment of resistance of the section (Mu = 0.156bd2fcu). The corresponding uniformly distributed load was computed from the well–known relationship between maximum moment and uniformly distributed load (udl) on beam and its effective span. The udl was imposed on each beam at different percentages of ultimate moment of resistance. All the beams were singly reinforced. The lever arm curve that permits the area of reinforcement to be calculated for singly reinforced beams was used. The corresponding deflection at each level of loading was calculated for each span. The well-established equations of deflection were used with some modifications that reflect the characteristics of the bamboo splints. The shear stress at each level of loading was calculated and compared with both allowable and ultimate values. The computed deflection for each loading case showed that the deflection of bamboo-reinforced beams increased with increase in value of applied moment and span but reduced with increase in the quantity of bamboo reinforcement in the beams. The results show that the optimum span for bamboo reinforcement in reinforced concrete beams based on cross-sectional dimensions of 225x450mm is 4000mm at optimum load of 60% Mu. Within this limit, the requirements of ultimate and serviceability limit states were achieved.
- ItemOpen AccessInvestigation on potential groundwater impacts and influence of local hydrogeology on natural attenuation of leachate at a municipal landfill.(IRSEN,CEERS, IAU, 2007) Longe, E.O.; Enekwechi, L.O.The paper investigated the impact of a municipal landfill operation on groundwater quality. It also investigated the role of local hydrogeology in the attenuation of leachate breakthrough into the groundwater resource.
- ItemOpen AccessImproving Engineering Education in Africa.(2008) Falade, F.Engineering education in Africa is faced with formidable challenges, ranging from poor funding to inadequate facilities, poor staff training, and weak linkages to the international engineering community, insufficient ICT facilities and infrastructure. The African Engineering Education Association was established in 2006. It aims at stimulating engineering education and addressing the inadequacies in Africa in order to fully develop the potential of engineers to contribute to African sustainable development.