scholarly journals Effect of Compactive Efforts on Strength of Laterites Stabilized with Sawdust Ash

2019 ◽  
Vol 5 (11) ◽  
pp. 2502-2514
Author(s):  
Olumide Moses Ogundipe ◽  
Jonathan Segun Adekanmi ◽  
Olufunke Olanike Akinkurolere ◽  
Peter Olu Ale
Keyword(s):  
Unconfined Compressive Strength ◽  
Soil Samples ◽  
Natural State ◽  
Unconfined Compression ◽  
Unconfined Compression Test ◽  
Future Studies ◽  
Moisture Contents ◽  
Increase With Increase ◽  
Two Samples ◽  
Compactive Effort

This study investigates the effects of different compactive efforts on the strength of laterites stabilized with sawdust ash (SDA). Laterites in the categories of A-7-5 and A-7-6 were considered because they are not suitable in the natural states as subgrade materials. The geotechnical properties of the laterites in their natural states were determined. The sawdust was burnt and sieved through 600micron. The sawdust ash (at 2%, 4%, 6%, 8% and 10%) was added to the laterites and the atterberg limits were determined, while the California bearing ratio and Unconfined compression test were determined using three compactive efforts (596, 1192 and 2682KN-m/m3).It was generally observed that the maximum dry densities of the natural and stabilised laterites increase with increase in the compactive efforts, while the optimum moisture contents reduce. The plasticity indices of the laterites increased with the addition of SDA. The optimum values of the MDDs (2006 and 1878 kg/m3) were observed at 4% and 6% SDA of 2682 kN-m/m3 compactive effort for samples A and B, respectively. The soaked and unsoaked CBR values of the soils at natural state are 4.89 and 16.33%, and 3.4 and 5.62% for samples A and B, respectively. The results indicate that the higher the compactive efforts, the higher the CBR values of the two samples. Increase in SDA contents of soil samples A and B showed a non-predictable trend on their CBR values. The Unconfined Compressive Strength values at natural and treated states fell below the requirements. Generally, it was found that the use of sawdust ash alone as stabilizer was not effective. Therefore, it was concluded that future studies should consider the use of the sawdust ash in combination with cement or lime.

scholarly journals Performance of THM behavior of sand-bentonite mixtures considering thermal effect

2021 ◽  
Vol 337 ◽  
pp. 01020
Author(s):  
Tomoyoshi Nishimura ◽  
Junichi Koseki
Keyword(s):  
Compressive Strength ◽  
Relative Humidity ◽  
Compression Test ◽  
Unconfined Compressive Strength ◽  
Triaxial Compression ◽  
Radioactive Waste Disposal ◽  
Unconfined Compression ◽  
Unconfined Compression Test ◽  
Sand Mixture ◽  
High Level

This study presented the overview on the behavior of bentonite-sand mixture used in high level radioactive waste disposal. Both unconfined compression test and triaxial compression test were conducted out that unsaturated-saturated bentonite-sand samples were applied temperature effect below 100 degrees Celsius. Unconfined compressive strength was determined with various temperatures and different relative humidity for unsaturated bentonite-sand specimens, so the growing of pore pressure due to heating was most significant for interpretation to THM behaviour of artificial barrier system compositing bentonite materials.

scholarly journals Capability of Pocket Penetrometer to Evaluate Unconfined Compressive Strength of Baghdad Clayey Soil

2018 ◽  
Vol 21 (1) ◽  
pp. 66 ◽  
Author(s):  
Azhar Sadiq Yasun
Keyword(s):  
Compressive Strength ◽  
Moisture Content ◽  
Unconfined Compressive Strength ◽  
Clayey Soil ◽  
Sample Type ◽  
Unconfined Compression ◽  
Unconfined Compression Test ◽  
Test Result

Unconfined compressive strength represents an important parameter for soil investigation report test results because the values of cohesion and allowable bearing capacity can directly obtained from the relevant test especially if the clayey soil layers are found at sufficient enough depth above water table level. This paper deals with simple comparison (based on (31) soil samples) between unconfined compressive strength (qu) obtained by using the pocket soil penetrometer tool and the unconfined compressive strength using the conventional test for the same sample penetrated by the pocket penetrometer with different soil moisture contents. Two triaxial specimens, sample type-1- with dimensions 38 X 79mm and type-2- with dimensions 33 X 79mm(diam. X height)) prepared in the libratory. It was found that the results refers that soil pocket penetrometer readings are closed enough to the results that obtained from the unconfined compression test result with certain conditions. The average percentage of difference between penetrometer readings and unconfined compression test result values was (1.103%) for sample type-1- and (1.53%) for sample type -2-. The maximum moisture content for all tests samples was (27.3%) and the minimum was (14.7%) while the average moisture content was(20.9%).

scholarly journals Comparison of the Use of Cement, Gypsum, and Limestone on the Improvement of Clay through Unconfined Compression Test

2019 ◽  
Vol 5 (2) ◽  
pp. 131
Author(s):  
Ika Puji Hastuty
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Soil Properties ◽  
Compression Test ◽  
Unconfined Compressive Strength ◽  
Soil Stabilization ◽  
Unconfined Compression ◽  
Unconfined Compression Test ◽  
Limestone Soil ◽  
Materials Used

Soil stabilization is an effort to improve soil properties by adding additives in the soil to increase the soil strength and maintain the shear strength of the soil. There are many materials which can be used as stabilizers. The materials used in this study were cement, gypsum, and limestone, then the compressive strength values were compared by using the Unconfined Compression Test (UCT). The mixture combinations used in this study were 1% to 10% of cement, gypsum, and limestone on clay by curing for 14 days. The compressive strength value resulted from the unconfined compression test on the original soil sample was 1.4 kg/cm2. The original soil was classified as moderately sensitive soil because the sensitivity value of the original soil was 2. After being stabilized with various mixtures of cement, gypsum, and limestone, soil stabilization using cement obtained the maximum unconfined compressive strength value is 3.681 kg/cm2 in the mixture of 10%. Similarly, the soil stabilization using limestone and gypsum also obtained its maximum unconfined compressive strength value in the mixture of 10% is 3.307 kg/cm2 and 2.975 kg/cm2, respectively.

Effect of unloading duration on unconfined compressive strength

1999 ◽  
Vol 36 (1) ◽  
pp. 166-172 ◽  
Author(s):  
M A Fam ◽  
M B Dusseault
Keyword(s):  
Compressive Strength ◽  
Pore Pressure ◽  
Unconfined Compressive Strength ◽  
Excess Pore Pressure ◽  
Triaxial Tests ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Coefficient Of Consolidation ◽  
Unconfined Compression Test ◽  
Excess Pore

This note examines the effect of unloading duration on unconfined compression test results. Artificial clayey specimens were prepared using the slurry consolidation technique. Extracted specimens were loaded vertically under K0 conditions, and the load was kept constant until the end of primary consolidation. Specimens were unloaded and unconfined compression tests were carried out at different times after unloading. It is observed that the longer the unloading duration, the lower the measured unconfined strength. This behavior is attributed to the presence of negative excess pore pressure that dissipates with time, reducing the strength. Using the measured coefficient of consolidation, the degree of excess pore pressure dissipation and therefore the average mean effective stress near the failure zone can be calculated at the time of failure. Mohr circles are drawn tangential to the total shear envelope, using the calculated mean effective stresses. Reasonable agreement between predicted and measured unconfined compressive strengths has been observed, suggesting that consolidation theory can be adopted to assess the effect of unloading duration on unconfined compressive strength. Finally, engineering applications using a similar concept are briefly discussed.Key words: clays, unloading, consolidation, unconfined compression tests, triaxial tests.

scholarly journals Anisotropic and age-dependent elastic material behavior of the human costal cartilage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matthias Weber ◽  
Markus Alexander Rothschild ◽  
Anja Niehoff
Keyword(s):  
Costal Cartilage ◽  
Indentation Test ◽  
Biomechanical Properties ◽  
Material Behavior ◽  
Cartilage Tissue ◽  
Elastic Behavior ◽  
Unconfined Compression ◽  
Unconfined Compression Test ◽  
Young’S Moduli ◽  
Age Related

AbstractCompared to articular cartilage, the biomechanical properties of costal cartilage have not yet been extensively explored. The research presented addresses this problem by studying for the first time the anisotropic elastic behavior of human costal cartilage. Samples were taken from 12 male and female cadavers and unconfined compression and indentation tests were performed in mediolateral and dorsoventral direction to determine Young’s Moduli EC for compression and Ei5%, Ei10% and Eimax at 5%, 10% and maximum strain for indentation. Furthermore, the crack direction of the unconfined compression samples was determined and histological samples of the cartilage tissue were examined with the picrosirius-polarization staining method. The tests revealed mean Young’s Moduli of EC = 32.9 ± 17.9 MPa (N = 10), Ei5% = 11.1 ± 5.6 MPa (N = 12), Ei10% = 13.3 ± 6.3 MPa (N = 12) and Eimax = 14.6 ± 6.6 MPa (N = 12). We found that the Young’s Moduli in the indentation test are clearly anisotropic with significant higher results in the mediolateral direction (all P = 0.002). In addition, a dependence of the crack direction of the compressed specimens on the load orientation was observed. Those findings were supported by the orientation of the structure of the collagen fibers determined in the histological examination. Also, a significant age-related elastic behavior of human costal cartilage could be shown with the unconfined compression test (P = 0.009) and the indentation test (P = 0.004), but no sex effect could be detected. Those results are helpful in the field of autologous grafts for rhinoplastic surgery and for the refinement of material parameters in Finite Element models e.g., for accident analyses with traumatic impact on the thorax.

Stabilization of Black Cotton Soil using Lime and Phosphogypsum

2021 ◽  
Vol 9 (4) ◽  
pp. 503-507
Keyword(s):  
Unconfined Compressive Strength ◽  
Expansive Soils ◽  
Soil Samples ◽  
Black Cotton Soil ◽  
Stabilization Method ◽  
Curing Period ◽  
Problematic Soils ◽  
Construction Purpose ◽  
Black Cotton Soils ◽  
Properties Of Soil

Expansive soils are problematic soils for Civil Engineers. Black cotton (BC) soils possess low strength and high compressibility, due to these properties black cotton soils are considered to be challenging one for analysis. To achieve desired properties of soil for construction purpose these black cotton soil must be enhanced to meet its requirement. To modify the properties of black cotton soils, many treatment methods are there. In this paper an attempt has been made to improve the properties of black cotton soil by using industrial waste through stabilization method. By stabilizing the soil properties are enhanced and make it suitable for subgrade construction. In this work, the combined effect of Lime and Phosphogypsum (PG) on compaction characteristics, Atterberg’s Limit, Unconfined Compressive Strength (UCS) for original soil, California Bearing Ratio (CBR) and direct shear Test of a black cotton soil with percentage varying of Lime and Phosphogypsum was carried out. The soil samples were tested for tri-axial compression test and CBR tests were carried out after 4 days curing period. From the results, it has been inferred that the black cotton soil treated with Lime and Phosphogypsum in the percentages of (4:4) has better strength characteristics. Hence, it may be concluded that Lime and Phosphogypsum can be used for stabilization of black cotton soils for pavement subgrade

scholarly journals INVESTIGATION ON THE ENVIROMENTAL EFFECT OF LOCAL PRODUCTION METHOD OF ALUMINIUM UTENSIL IN KANO

2020 ◽  
Vol 4 (3) ◽  
pp. 256-262
Author(s):  
Y. I. Yakubu ◽  
I. A. Yola
Keyword(s):  
Heavy Metals ◽  
Water Samples ◽  
Production Method ◽  
Soil Samples ◽  
Permissible Limit ◽  
Limit Set ◽  
Local Production ◽  
Two Samples ◽  
S Model ◽  
Concentration Levels

This research investigated the environmental effect of local production methods of aluminium utensils in Bachirawa, Ungogo local government Kano. Three soil samples and two samples of water were collected from sites A, B,C, D and E. The samples were then taken to faculty of agriculture for analysis. Atomic absorption spectrophotometer (A A S model No 240 FSAA) was used to determine the concentration levels of heavy metals in the samples. The results show that, the concentration levels of  heavy metals in the soil samples A, B and C are:  Zn ranges between  (1158.13 - 11,117.80)  mg/kg; Mn  between  (285.719 – 1809.672) mg/kg; Cd between (0.026 – 0.540) mg/kg; Cr (0.498 – 0.832) mg/kg and Pb between (42.54 - 285.53) mg/kg. The observed concentration levels in water samples for Zn ranges between (0.2411 – 0.4435)mg/l; Cd between (0.091 – 0.123) mg/l; Cr between (0.015 – 0.022) mg/l; Mn between (0.284 – 0.728) mg/l and Pb between (0.00-0.08) mg/l. Zinc and Manganese have higher concentration levels than the recommended  permissible limit set by European Union (EU) and  United Kingdom(UK)  while Cd, Cr and  Pb have lower concentration levels than the recommended permissible limit set by EU and UK in soil samples  A, B and C. The concentration levels of Mn, Cd and Pb in water samples were higher than the permissible limit set by World Healh Organization (WHO) whereas Zn and Cr have concentrations lower than the recommended permissible limit set by 

scholarly journals A Computational Model of Non-optimal Suspiciousness in the Minnesota Trust Game

2021 ◽  
Author(s):  
Rebecca Kazinka ◽  
Iris Vilares ◽  
Angus MacDonald
Keyword(s):  
Decision Making ◽  
Risk Aversion ◽  
Computational Model ◽  
Inequity Aversion ◽  
Trust Game ◽  
Social Decision ◽  
Future Studies ◽  
Two Samples ◽  
Highly Correlated ◽  
Social Decision Making

This study modeled spite sensitivity (the worry that others are willing to incur a loss to hurt you), which is thought to undergird suspiciousness and persecutory ideation. Two samples performed a parametric, non-iterative trust game known as the Minnesota Trust Game (MTG). The MTG is designed to distinguish suspicious decision-making from otherwise rational mistrust by incentivizing the player to trust in certain situations. Individuals who do not trust even under these circumstances are particularly suspicious of their potential partner’s intentions. In Sample 1, 243 undergraduates who completed the MTG showed less trust as the amount of money they could lose increased. However, for choices where partners had a financial disincentive to betray the player, variation in the willingness to trust the partner was associated with suspicious beliefs. To further examine spite sensitivity, we modified the Fehr-Schmidt (1999) inequity aversion model, which compares unequal outcomes in social decision-making tasks, to include the possibility for spite sensitivity. In this case, an anticipated partner’s dislike of advantageous inequity (i.e., guilt) parameter could take on negative values, with negative guilt indicating spite. We hypothesized that the anticipated guilt parameter would be strongly related to suspicious beliefs. Our modification of the Fehr-Schmidt model improved estimation of MTG behavior. We isolated the estimation of partner’s spite-guilt, which was highly correlated with choices most associated with persecutory ideation. We replicated our findings in a second sample, where the estimated spite-guilt parameter correlated with self-reported suspiciousness. The “Suspiciousness” condition, unique to the MTG, can be modeled to isolate spite sensitivity, suggesting that spite sensitivity is separate from inequity aversion or risk aversion, and may provide a means to quantify persecution. The MTG offers promise for future studies to quantify persecutory beliefs in clinical populations.

scholarly journals Draft Requirement of Two Animal - Drawn Institute for Agricultural Research (IAR) Weeders

2020 ◽  
pp. 14-20
Author(s):  
Y. A. Unguwanrimi ◽  
A. M. Sada ◽  
G. N. Ugama ◽  
H. S. Garuba ◽  
A. Ugoani
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Bulk Density ◽  
Soil Moisture Content ◽  
Agricultural Research ◽  
Soil Samples ◽  
Soil Conditions ◽  
Experimental Plot ◽  
Moisture Contents ◽  
Loam Soil

Draft requirements of two animal – drawn (IAR) weeders operating on loam soil were determined in the study. The implements include a straddle row weeder and an emcot attached rotary weeder evaluated under the same soil conditions, using a pair of white Fulani breed of oxen. The animal draft requirement was first estimated from the animal ergonomics measurements. Using area of 0.054 hectare as experimental plot for each implement the draft requirement of each implement was investigated after taking soil samples for soil moisture content and bulk density determinations. The implements tested showed variation in their average draft requirement. The straddle row weeder had the highest value of 338.15 N respectively while the emcot attached rotary weeder had the lowest value of 188.12 N with 47.03%, respectively. The average soil moisture contents and bulk density were 13.0% and 1.46%/cm3, respectively.

scholarly journals Study a concentration of Uranium for samples of soil from Falluja City using PM-355

2017 ◽  
Vol 14 (1) ◽  
pp. 80-84
Author(s):  
Baghdad Science Journal
Keyword(s):  
Neutron Source ◽  
Uranium Concentration ◽  
Track Detector ◽  
Soil Samples ◽  
Thermal Neutrons ◽  
Military Operations ◽  
Standard Samples ◽  
Fission Tracks ◽  
Two Samples ◽  
Back Ground

In this study a concentration of uranium was measured for twenty two samples of soil distributed in many regions (algolan, almoalmeen, alaskary and nasal streets) from Falluja Cityin AL-Anbar Governorate in addition to other region (alandlos street) as a back ground on the Falluja City that there is no military operations happened on it. The uranium concentrations in soil samples measured by using fission tracks registration in (PM-355) track detector that caused by the bombardment of (U) with thermal neutrons from (241Am-Be) neutron source that has flux of (5×103n cm-2 s-1). The concentrations values were calculated by a comparison with standard samples. The results shows that the uranium concentrations algolan street varies from(1.976- 2.736ppm), almoalmeen street varies from (1.895-2.614ppm), and alaskary street varies from (1.657-2.476ppm), and nasal street (1.657-2.476ppm) the average uranium concentration in other region (alandolos) (0.736-1.588ppm). As a conclusion from the study uranium concentration in the four region above that have military operations is relatively higher than back ground

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