scholarly journals Geoengineering Assessment of Subgrade Highway Structural Material along Ijebu Owo – Ipele Pavement, Southwestern Nigeria

2020 ◽  
pp. 57-69
Keyword(s):  
Shear Strength ◽  
Clay Mineralogy ◽  
California Bearing Ratio ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Southwestern Nigeria ◽  
Kaolinite Clay ◽  
Static Water ◽  
Under Construction ◽  
Geotechnical Tests

Geochemical, geotechnical, and geophysical investigations were carried out along Migmatite gneiss underlain Iyere – Ipele pavement (under construction) in order to assess the suitability of the imported subgrade soil. Also static water level (SWL) was obtained from five open wells along the highway. The geotechnical tests include specific gravity, grain size analysis, consistency limits, consolidation, compaction, and California Bearing Ratio (CBR), and shear strength; while geochemical tests were analyzed using X-ray fluorescence and Atomic Absorption Spectrophotometer (AAS). The results show that SiO2, Al2O3 and Fe2O3 constitute an average of 46.2%, 23.30% and 26.54% respectively of the soils chemical composition. The silica- sesquioxide ratio of the samples ranges from 0.89 to 0.96 and classified as true laterite. The topsoil along the highway is made of moderately competent/competent soil with resistivity ranging from 298 – 924 ohm-m and thickness of 3.1 - 8.2 m. The SWL varies from 3.3 - 5.5 m with an average of 4.3 m (moderately low). The soils are characterized by high California Bearing Ratio values, moderate shear strength (150 – 200kpa), and unconfined compressive strength (300 – 420kpa) with predominant kaolinite clay mineralogy group. The AASHTO and USCS classification system rate the soils as good and fair/good respectively.

scholarly journals Compositional and industrial assessment of Isua-Akoko, Akure, Ayadi and Lafe (Ode Aye) clay deposits of Ondo state, Nigeria

1970 ◽  
Vol 21 (1) ◽  
pp. 41-49
Author(s):  
O Adegbuyi ◽  
GP Ojo ◽  
AJ Adeola ◽  
MT Alebiosu
Keyword(s):  
Chemical Properties ◽  
Fine Sand ◽  
Coarse Sand ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Medium Sand ◽  
Southwestern Nigeria ◽  
Firing Test ◽  
Clay Deposits ◽  
Ondo State

The physical and chemical properties of clay deposits around Isua-Akoko, Akure, Lafe and Ayadi in Ondo State southwestern Nigeria have been examined. The results have shown that Isua-Akoko, Akure and Lafe Clays are plastic fire clays while Ayadi clay is kaolinite. Grain size analysis reveals that Isua Akoko Clay contains 45% of clay, 18% silt, 12% fine sand,14% medium sand and 11% coarse sand and no gravel; Akure clay contains 42% clay, 14% silt, 13% fine sand, 20% medium sand and 8% coarse sand with 1% gravel. Lafe Clay contains 21% clay, 8% silt, 25% fine sand, 37% medium sand and 8% coarse sand with 1% gravel while Ayadi clay contains 83% clay and 17% silt. The liquid limits of these clay samples range from 41% to 73%% and plastic limits range from 18% to 26% respectively. The chemical analysis reveals that the most abundant mineral is silica (60.97%) and aluminum was next in abundance (23.69%) while other oxides are low. The results show that Isua-Akoko and Akure are residual while Lafe and Ayadi are sedimentary and transported Clays. The firing test, PH, and bleaching tests of the clays are also discussed. The chemical and physical characteristics of the clay deposits are strongly indicative of their industrial importance in the production of ceramics, refractories, paving bricks, paint and pharmaceutical products.KEYWORDS: Kaolinite, fire clay, gravel, ceramics and alumina.

scholarly journals Micro-structures, mineralogy and geochemistry of clay size fraction (< 2 µm) of thrust zones of western Nepal Siwaliks (Karnali area)

1998 ◽  
Vol 18 ◽  
pp. 239-248
Author(s):  
Pascale Huyghe ◽  
Albert Galy ◽  
Jean- Louis Mugnier
Keyword(s):  
Shear Zone ◽  
Hot Springs ◽  
Clay Fraction ◽  
Size Fraction ◽  
Clay Mineralogy ◽  
Shear Zones ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Actual Surface ◽  
Micro Structures

Shear zones of the Main Dun Thrust (MDT) of the Siwaliks of western Nepal have been investigated in order to specify the deformation mechanisms and mineral transformations. The Riedel fractures and cleavage are developed. They are responsible for the scaly fabric of the fault zones and generate a "tectonic mixture" of both the Upper and Lower Siwaliks at the footwall and hangingwall of the MDT. Grain-size analysis of samples from the shear zones indicates a strong cataclastic deformation. Clay mineralogy varies significantly within the shear zone. However, the smectites abundance is higher in the shear zone than in the Upper and Lower Siwaliks and may exceed 40% of the <2 µm clay fraction. The isotopic oxygen composition of clay fractions in the shear zone gives δ18O of smectites that implies neoformation. The temperature of smectite neoformation is 40 to 60°C higher than pedogenic smectites present in the borders. δD of fluid inclusion of calcite associated to deformation show values consistent with water similar to the actual surface water and δ18O of mineral implies temperature of crystallisation around 50°C. These low temperatures are in good agreement with the precipitation of smectites and kaolinites. Fluids sampled in hot springs of the Siwaliks of western Nepal have a meteoric origin with respect to the stable isotopes but are enriched in Na and depleted in K. The chemistry suggests the partial dissolution of feldspar and neoformation of smectites induced by fluid circulation. It is presumed that shearing and crushing take place during seismic slip increasing the exchanging mineral surfaces whereas mineralogical reactions occur during interseismic periods.

scholarly journals Investigation into Erosion induced Highway Structural Failure along Ifon—Benin Highway, Southwestern Nigeria

2020 ◽  
Author(s):  
Olumuyiwa Olusola Falowo
Keyword(s):  
Traffic Load ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Natural Soil ◽  
Stream Channels ◽  
Southwestern Nigeria ◽  
The Road ◽  
The Earth ◽  
Clayey Silt ◽  
Limit Test

Abstract Geotechnical investigation was carried out at two failed segments along Ifon-Benin Highway, with the aim of determining cause, nature, and extent of the road failure. Eight in-situ cone penetration tests was carried out to a depth of about 20 m with a lateral spacing of 20 m. This was complemented by collection of eight soil samples at different depths within the failed segments and analyzed in the laboratory. The laboratory tests conducted were grain size analysis, Atterberg limit test, compaction test, California bearing ratio, undrained unconfined triaxial test. The failure that existed in both locations are around the embankment, shoulder/edge and wearing course of the highway, due to ingression of water into the subgrade since the earth (natural soil) embankment structure had been eroded by rain water. The laboratory geotechnical results revealed that all the parameters could not meet up with the federal ministry of works and housing specification of Nigeria, with plasticity index greater than 20 %, % fines greater than 35 %, CBR values less than 80 % minimum recommended, shear strength parameters; angle of friction and cohesion are less than minimum of 30° and 50 kPa respectively. The CPT revealed predominant sandy silt to clayey silt topsoil and clay substratum with an inferred compressive strength of 20 – 40 KN/m2. At both failed segments, the clayey substratum is seriously affected within the upper 6 m. The ingression of water into these foundation structures was due to compromise of the design/construction engineer, since a bridge was supposed to be erected across these two locations. Hence the stream channels across the highway were blocked by the earth-fill embankment. Therefore during wet season, pool of water that supposed to flow across the road through bridge system, continue to dissolve the embankment, and consequently infiltrate into the subgrade. This makes the highway to settle largely under traffic load. In addition, incessant heavy flooding around the embankment/shoulder of the highway might have induced the failure since a bridge was supposed to have been constructed across the two failed segments. This flooded water might have infiltrated into the pavement structural material leading to looseness, and less-cohesion of the layers which invariably reduces subgrade support and weakens various pavement layers.

scholarly journals Pemanfaatan Semen Slag untuk Stabilisasi Tanah dan Pengaruhnya Terhadap Nilai CBR Berdasarkan Variasi Kadar Air Sisi Basah Optimum

2021 ◽  
Vol 18 (2) ◽  
pp. 132-140
Author(s):  
Enden Mina ◽  
Woelandari Fathonah ◽  
Rama Indera Kusuma ◽  
Naufal Abdurrasyid
Keyword(s):  
Bearing Capacity ◽  
Road Construction ◽  
Soil Improvement ◽  
California Bearing Ratio ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Ratio Test ◽  
High Plasticity ◽  
Slag Cement ◽  
Test Soil

Many of the damage in road construction occurred because the soil did not have a good bearing capacity, therefore soil improvement was needed to increase the strength of the soil. One of the damaged roads that occur due to the lack of soil bearing capacity is at Priyayi Mosque Village Road, Kasemen District, Serang City which has a low carrying capacity with a CBR value of 1.99%. In this study, several tests were carried out, soil physical and California Bearing Ratio test. Soil physical tests carried out were water content, soil density, grain size analysis, Atterberg limits, compaction test and, CBR with the addition of slag cement with variations of 0%, 5%, 10%, 15% based on Variation of optimum wet side moisture content. The result of soil physical properties testing obtained the type of soil is an organic clay with high plasticity. The results of the California Bearing Ratio test on the original soil had a CBR value of 2.4% and there was an increase to the optimum at the addition of 15% Slag Cement in 0 and 3 days of curing with a CBR value of 11.2% and 15.25%. Based on these results, it can be concluded that the cement slag content of 15% with 3 days of curing time can increase the bearing capacity of the soil and fulfill the requirements as a good road subgrade

scholarly journals Grain size analytical and geochemical data of sediments from Ishakare and Alatan streams in Akungba-Akoko, Southwestern Nigeria

2021 ◽  
Vol 6 (2) ◽  
pp. 44-50
Author(s):  
Olumuyiwa A. Odundun ◽  
Keyword(s):  
Grain Size ◽  
Mean Value ◽  
Grain Size Analysis ◽  
Geochemical Data ◽  
Size Analysis ◽  
Dispersal Pattern ◽  
Southwestern Nigeria ◽  
Elemental Concentrations ◽  
Major Oxide ◽  
Geochemical Analyses

The identification of anomalous elemental concentrations and the prediction of their dispersal pattern play a key role in geochemical exploration. Stream sediments are important focus in this aspect. Nine (9) sediment samples collected from Ishakare and Alatan Streams in Akungba-Akoko were subjected to grain size and inorganic geochemical analyses in order to determine their grain sizes distribution, travel distances, elemental concentrations and origin. Results of grain size analysis show that streams sediments are mostly medium-grained, poorly-moderately sorted and ranged from fine to strongly coarse skewed suggesting that they have been transported relatively not too far away from their sources under high to low energy. SiO2 is a dominant major oxide with concentration values ranging between 64.81 and 71.59 wt.% with a mean value of 68.07 wt.%. Abundance of Al2O3 indicates that samples are from Aluminum-rich source bed rock. The weights of Fe2O3 and TiO2 also point to gneissic rocks as a probable source. Generally, concentrations of trace elements were found to be low indicating that the contamination statue of the sediments ranges from unpolluted to moderately polluted

scholarly journals Geochemical and Mineralogical Characterisation of Historic Zn–Pb Mine Waste, Plombières, East Belgium

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Srećko Bevandić ◽  
Rosie Blannin ◽  
Jacqueline Vander Auwera ◽  
Nicolas Delmelle ◽  
David Caterina ◽  
...  
Keyword(s):  
Grain Size ◽  
Mine Waste ◽  
Geophysical Methods ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Mine Wastes ◽  
Metallurgical Waste ◽  
High Concentration ◽  
Geochemical Properties ◽  
Potential Applications

Mine wastes and tailings derived from historical processing may contain significant contents of valuable metals due to processing being less efficient in the past. The Plombières tailings pond in eastern Belgium was selected as a case study to determine mineralogical and geochemical characteristics of the different mine waste materials found at the site. Four types of material were classified: soil, metallurgical waste, brown tailings and yellow tailings. The distribution of the mine wastes was investigated with drill holes, pit-holes and geophysical methods. Samples of the materials were assessed with grain size analysis, and mineralogical and geochemical techniques. The mine wastes dominantly consist of SiO2, Al2O3 and Fe2O3. The cover material, comprising soil and metallurgical waste is highly heterogeneous in terms of mineralogy, geochemistry and grain size. The metallurgical waste has a high concentration of metals (Zn: 0.1 to 24 wt.% and Pb: 0.1 to 10.1 wt.%). In the tailings materials, Pb and Zn vary from 10 ppm to 8.5 wt.% and from 51 ppm to 4 wt.%, respectively. The mining wastes comprises mainly quartz, amorphous phases and phyllosilicates, with minor contents of Fe-oxide and Pb- and Zn-bearing minerals. Based on the mineralogical and geochemical properties, the different potential applications of the four waste material types were determined. Additionally, the theoretical economic potential of Pb and Zn in the mine wastes was estimated.

scholarly journals Centennial Impacts of the East Asian Summer Monsoon on Holocene Deltaic Evolution of the Huanghe River, China

2021 ◽  
Vol 11 (6) ◽  
pp. 2799
Author(s):  
Yanping Chen ◽  
Wenzhe Lyu ◽  
Tengfei Fu ◽  
Yan Li ◽  
Liang Yi
Keyword(s):  
Grain Size ◽  
Yellow River ◽  
Asian Summer Monsoon ◽  
River Delta ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Sediment Grain Size ◽  
Huanghe River ◽  
Huanghe River Delta ◽  
The Huanghe River

The Huanghe River (Yellow River) is the most sediment laden river system in the world, and many efforts have been conducted to understand modern deltaic evolution in response to anthropological impacts. However, the natural background and its linkage to climatic changes are less documented in previous studies. In this work, we studied the sediments of core YDZ–3 and marine surface samples by grain-size analysis to retrieve Holocene dynamics of the Huanghe River delta in detail. The main findings are as follows: The mean value of sediment grain size of the studied core is 5.5 ± 0.9 Φ, and silt and sand contents are 5.2 ± 2.3% and 8.2 ± 5.3%, respectively, while the variance of clay particles is relatively large with an average value of 86.4 ± 8.5%. All grain-size data can be mathematically partitioned by a Weibull-based function formula, and three subgroups were identified with modal sizes of 61.1 ± 28.9 μm, 30.0 ± 23.9 μm, and 2.8 ± 1.6 μm, respectively. There are eight intervals with abrupt changes in modal size of core YDZ–3, which can be correlated to paleo-superlobe migration of the Huanghe River in the Holocene. Based on these observations, the presence of seven superlobes in the history are confirmed for the first time and their ages are well constrained in this study, including Paleo-Superlobes Lijin (6400–5280 yr BP), Huanghua (4480–4190 yr BP), Jugezhuang (3880–3660 yr BP), Shajinzi (3070–2870 yr BP), Nigu (2780–2360 yr BP), Qikou (2140–2000 yr BP), and Kenli (1940–1780 and 1700–1650 yr BP). By tuning geomorphological events to a sedimentary proxy derived from core YDZ–3 and comparing to various paleoenvironmental changes, we proposed that winter climate dominated Holocene shifts of the Huanghe River delta on millennial timescales, while summer monsoons controlled deltaic evolution on centennial timescales.

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