The results of a study conducted to facilitate the development of road pavement performance models that are appropriate for Nigeria and similar developing countries and could predict the rate of deterioration over their lifespan have been presented. Comprehensive investigations were carried out on the expressway linking Lagos (the economic nerve centre of Nigeria) with Ibadan (the largest city in West Africa)-apparently one of the most heavily trafficked roads in the country. Data relating to traffic characteristics, pavement condition ratings, distress types, pavement thickness, roughness index, rainfall and temperature, were collected. Models were developed to determine Pavement Condition Score (PCS) and International Roughness Index (IRI). Stepwise Regression was used to analyse the data and quantify the impact of key input parameters on the PCS and IRI. Parameters such as depth of ruts and area of pot holes were found to be statistically significant in predicting PCS while number of patches, length of longitudinal cracks and depth of ruts were statistically significant in predicting IRI. The models can be used for planning road maintenance programs, thus minimizing the need for comprehensive data collection on pavement condition before the maintenance exercise, which is costly and time consuming.
Exploration and exploitation for hydrocarbon are associated with a lot of complexities, it is therefore necessary to integrate available geologic models for accurate hydrocarbon prospecting and risk analysis. This study is aimed at determining the structural, petrophysical and volumetric parameters for reservoir evaluation within the Rancho field. 3D seismic data was used for evaluating the hydrocarbon potential of the field. A suite of well logs but not limited to gamma ray logs (GR), deep resistivity log (DRES), neutron log (NPHI) and density log (RHOB) from four (4) wells were employed in characterising dynamic properties of the reservoirs. The GR log was used in lithology identification while the resistivity log was used in identifying probable hydrocarbon bearing sands. A correlation exercise was carried out to identify lateral continuity and discontinuity of facies across the wells. Thereafter petrophysical parameters were analysed from the suite of wire line logs. Major faults were mapped on the 3D seismic data and identified hydrocarbon bearing sand tops from the well logs were mapped as horizons on the seismic section, maps were generated and volumetric analysis was done. Nine (9) hydrocarbon sands (Sands A -I) were identified within the study area. The well log revealed an alternation of sand and shale layers as well as shale layers increased in thickness with depth, while the sand bodies reduced in thickness with depth which characterized the Abgada Formation of the Niger Delta. The effective porosities of the sands range from 21% -31%, the permeability ranges from 28% -44%, 70% -80% for the net to gross, volume of shale range from 14% -40% and hydrocarbon saturation ranges from 63% -82%. Twelve (12) faults were mapped within the study area and the structural styles revealed a fault assisted closures. The volumetric analysis showed that Sand F had Stock Tank Oil Initially In Place
The nutritional status of 240 children between the ages of 2 and 15 years in communities that use or do not use soya beans was evaluated by conventional methods. There were significant differences (p <.05) in the nutritional status of pre-school (2-5 yr) and school-age children (6-15 yr) in the three communities. Using weight-for-height as an index of acute malnutrition, 32.5%, 25.5%, and 22.6% of preschool children were normal in Kurmin Masara, Kaya, and Makera, respectively, as were 44.6%, 24.4%, and 21.7% of school-age children. Kurmin Masara, a community producing and using soya beans, had a significantly higher percentage (p < .05) of nutritionally normal and a lower percentage of severely malnourished children than the other two villages. Generally, malnutrition was more pronounced in school-age children in the three communities. Soya bean accounted for 34.4%, 28.5%, and 1.3% of the protein intake of children 2 to 15 years of age in Kurmin Masara, Kaya, and Makera, respectively.Our findings appear to validate the importance of soya bean in the diet of children, especially in this period of economic recession when animal protein sources are very expensive. Extension service efforts are necessary in Nigeria and other African countries to increase soya bean production and use to improve the nutritional status of the population, particularly young children.
<p>Palm kernel shells were assessed as aggregate in concrete and laterite blocks. Results showed that laterite blocks reinforced with kernel shells at the optimum proportion of 1:4 (kernel shells:laterite) by volume were about 15% stronger than plain laterite blocks. The strength of laterite blocks reinforced with kernel shells also compared favorably with strength of sandcrete blocks which are popularly used as partitions in buildings. However, replacement of crushed stone aggregate with kernel shells in concrete blocks resulted in a strength reduction of about 50%. Therefore, palm kernel shells are not good substitutes for crushed stone aggregates in concrete.</p>
Pavement failure has contributed immensely to loss of lives, disruption to normal daily activities and increase amount of money being spent on maintenance annually. One of the causes is associated with inadequate investigations on subgrade materials. This study aimed at examining the geotechnical parameters as factors of pavement failure along Lagos–Ibadan Expressway. Samples were collected at the failed and stable portions on some selected road segments and subjected to laboratory tests including Natural Moisture Content (NMC), Linear Shrinkage(LS), particle size distribution and California Bearing Ratio(CBR). The NMC along the failed sections was on the high side (ranged from 13.11% to 26.89%) compared with the stable sections (ranged from 11.11% to 16.40%). Most of the tested soils have percentage passing 0.075mm sieve more than 35% maximum required by the Federal Ministry of Works and Housing for subgrade materials. The maximum dry density(MDD) for the samples at failed and stable sections ranged from 1550 kg/m3 to 1860 kg/m3; 1650 kg/m3 to 1980 kg/m3 respectively while the Optimum Moisture Content(OMC) ranged from 8.30% to 20.30%. The soaked CBR values ranged from 2% to 17% while the unsoaked values ranged from 4% to 25%. The increase in NMC along the failed portions could be as a result of high water table along these sections. Some of the materials at failed locations had values of LS > 8% which suggests high susceptibility to shrinkage and swelling which results in differential settlement and contributed to pavement failure along these sections of the road. Keywords: Geotechnical, Pavement failures, subsurface investigations, Expressway, subgrade materials.
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