scholarly journals Study on the Permeability Characteristics of Polyurethane Soil Stabilizer Reinforced Sand

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Jin Liu ◽  
Xiaohui Qi ◽  
Da Zhang ◽  
Qiao Feng ◽  
Yong Wang ◽  
...  
Keyword(s):  
Water Flow Rate ◽  
Sand Particle ◽  
Curing Time ◽  
Permeability Test ◽  
Surface Protection ◽  
Permeability Characteristics ◽  
Reinforced Sand ◽  
Sand Surface ◽  
Soil Stabilizer ◽  
Layer Increase

A polymer material of polyurethane soil stabilizer (PSS) is used to reinforce the sand. To understand the permeability characteristics of PSS reinforced sand, a series of reinforcement layer form test, single-hole permeability test, and porous permeability test of sand reinforced with PSS have been performed. Reinforcement mechanism is discussed with scanning electron microscope images. The results indicated that the permeability resistance of sand reinforced with polyurethane soil stabilizer is improved through the formation of reinforcement layer on the sand surface. The thickness and complete degree of the reinforcement layer increase with the increasing of curing time and PSS concentration. The water flow rate decreases with the increasing of curing time or PSS concentration. The permeability coefficient decreases with the increasing of curing time and PSS concentration and increases with the increasing of depth in specimen. PSS fills up the voids of sand and adsorbs on the surface of sand particle to reduce or block the flowing channels of water to improve the permeability resistance of sand. The results can be applied as the reference for chemical reinforcement sandy soil engineering, especially for surface protection of embankment, slope, and landfill.

scholarly journals Laboratory Tests on Effectiveness of Environment-Friendly Organic Polymer on Physical Properties of Sand

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jin Liu ◽  
Zezhuo Song ◽  
Yuxia Bai ◽  
Zhihao Chen ◽  
Jihong Wei ◽  
...  
Keyword(s):  
Physical Properties ◽  
Laboratory Tests ◽  
Organic Polymer ◽  
Water Stability ◽  
Environment Friendly ◽  
Surface Protection ◽  
Reinforced Sand ◽  
Sand Surface ◽  
Erosion Test ◽  
The Stability

The poor water stability, high penetrability, and low antierosion of sand affect the stability of the sandy soil slope. To understand the effectiveness of environment-friendly organic polymer on these physical properties of sand, a series of laboratory tests including water stability test, penetration test, and runoff erosion test of polymer reinforced sand were performed. The results of tests indicated that the organic polymers have obvious effects on the reinforced sand. The water stability of polymer reinforced sand had been improved strongly. All the reinforced sands with polymer ≥0.3% remained a stable structure at immersing time of 24 hours. The penetrability of the reinforced sand decreased with the increase of the polymer. The reinforced sand with polymer ≥7% was impermeable. The erosion resistance of sand increased with the increase of polymer content. With the polymer ≥4%, the sand surface kept intact with the scouring time more than 2 hours. The results could be applied as the reference for organic polymer reinforced sand engineering, especially for surface protection of embankment, slope, and landfill.

scholarly journals Experimental Study on Unconfined Compressive Strength of Organic Polymer Reinforced Sand

2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
Jin Liu ◽  
Qiao Feng ◽  
Yong Wang ◽  
Da Zhang ◽  
Jihong Wei ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Organic Polymer ◽  
Sand Particle ◽  
Curing Time ◽  
Time Saving ◽  
Natural Sand ◽  
Reinforced Sand ◽  
Practical Engineering ◽  
Curing Method

The natural sand is loose in structure with a small cohesive force. Organic polymer can be used to reinforce this sand. To assess the effectiveness of organic polymer as soil stabilizer (PSS), a series of unconfined compressive strength tests have been performed on reinforced sand. The focus of this study was to determine a curing method and a mix design to stabilize sand. The curing time, PSS concentration, and sand density were considered as variables in this study. The reinforcement mechanism was analyzed with images of scanning electron microscope (SEM). The results indicated that the strength of stabilized sand increased with the increase in the curing time, concentration, and sand density. The strength plateaus are at about curing time of 48 h. The UCS of samples with density of 1.4 g/cm3 at 10%, 20%, 30%, 40%, and 50% PSS concentration are 62.34 kPa, 120.83 kPa, 169.22 kPa, 201.94 kPa, and 245.28 kPa, respectively. The UCS of samples with PSS concentration of 30% at 1.4 g/cm3, 1.5 g/cm3, and 1.6 g/cm3 density are 169.22 kPa, 238.6 kPa 5, and 281.69 kPa, respectively. The chemical reaction between PSS and sand particle is at its microlevel, which improves the sand strength by bonding its particles together and filling the pore spaces. In comparison with the traditional reinforcement methods, PSS has the advantages of time saving, lower cost, and better environment protection. The research results can be useful for practical engineering applications, especially for reinforcement of foundation, embankment, and landfill.

scholarly journals Unconfined Compressive Strength Characteristics of Overboulder Asbuton and Zeolite Stabilized Soft Soil

2021 ◽  
Vol 7 (1) ◽  
pp. 40-48
Author(s):  
Noor Dhani ◽  
Ahmad Gasruddin ◽  
Hartini Hartini ◽  
La Baride
Keyword(s):  
Compressive Strength ◽  
Soil Stabilization ◽  
Soft Soil ◽  
Pozzolanic Reaction ◽  
Silica Content ◽  
Curing Time ◽  
Natural Pozzolan ◽  
Soil Stabilizer ◽  
Proctor Test ◽  
High Silica

Soft soil was one of the most widely encountered problems in construction, especially for archipelago countries which most of its area was lowland with a high deposit of soft soil. To overcome this problem, soil stabilization was one of the most widely used as a solution. Soil stabilization in general uses chemical substances that are classified as pozzolan material. Pozzolan material uses its capability to strengthen the cohesion of soil grains. Mostly, pozzolan material consists of silica. Overboulder asbuton and zeolite were examples of natural pozzolan material in Indonesia. Both materials have a high silica content. Thus, the author interested to figure out the mechanical behavior of these two substances as a soil stabilizer. This research was a correlating study to the previous paper with the same author which discusses the overboulder asbuton as a soil stabilizer. Overboulder added to the mix is determined as 15%, with varied zeolite percentages applied to examine the differences. The UCT was conducted according to ASTM D-2166 as a parameter. As the standard remolding method, a standard proctor test was conducted to determine the optimum moisture content and the maximum density of each mix. While the UCT specimens were tested at the certain curing time for each composition. The curing time applied was 0, 7, 14, and 28 days. By this curing period, the effective pozzolanic reaction that occurs for each composition could be determined. The result shows that zeolite addition to overboulder asbuton could increase the soil density and increase its compressive strength. It is indicated that overboulder asbuton and zeolite mix could be a proper alternative as a soil stabilizer. Doi: 10.28991/cej-2021-03091635 Full Text: PDF

Numerical Study on Aeolian Sand Ripples Forming and Moving Process in Desert Highway

2011 ◽  
Vol 462-463 ◽  
pp. 1032-1037 ◽  
Author(s):  
Abdurahman Ablimit ◽  
Mamtimin Gheni ◽  
Zhong Hua Xu ◽  
Mamatjan Tursun ◽  
Xamxinur Abdikerem
Keyword(s):  
Flow Field ◽  
Numerical Study ◽  
Numerical Models ◽  
Flow Direction ◽  
Sand Particle ◽  
Forming Process ◽  
Sand Surface ◽  
Airflow Field ◽  
Sand Flow ◽  
Desert Highway

In this paper, the sand break into highway problem in desert, which is caused by the sand flow blown by wind, is studied. The mathematical models are introduced by considering the fixed, semi-fixed and free sand desert fields based on the fluid dynamics and the sand particle dynamics. Different kinds of numerical models are made by changing the desert highway height, wind flow direction and its uniformity. The weak coupling method is used due to spatial relationships between air flow field and the sand flow field. Finally, by coupling the airflow field and sand flow field with desert highway, the numerical simulations of sand forming process on desert highway are conducted. The numerical results shown, that the wind blown sand breaks into highway easier when wind direction perpendicular highway and if the highway height higher than the range size of the sand surface the wind blown sand break into highway is more difficult.

scholarly journals Self-Healing Performance Evaluation of Concrete Incorporating Inorganic Materials Based on a Water Permeability Test

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3202
Author(s):  
Kwang-Myong Lee ◽  
Hyung-Suk Kim ◽  
Do-Keun Lee ◽  
Kyung-Joon Shin
Keyword(s):  
Water Permeability ◽  
Standardized Test ◽  
Water Flow Rate ◽  
Test Methods ◽  
Inorganic Materials ◽  
Self Healing ◽  
Permeability Test ◽  
Research Activities ◽  
Number Of Factors ◽  
Rational Evaluation

Research activities that have focused on the development and understanding of self-healing concrete have proposed various technologies intended to enhance self-healing capacity. The self-healing performance cannot be identified sufficiently with either a single test or a specific parameter because there are a number of factors that influence the performance of self-healing. Thus, it has become necessary to provide standardized test methods that make it possible to verify and compare the performance of self-healing materials. In this paper, self-healing mortars based on inorganic admixtures, which are developed for sealing 0.3 mm cracks with a healing index of 90%, are produced and used to validate the water permeability test and to propose protocols for the evaluation of self-healing performance. The healing performances of three self-healing mortars and a plain mortar as a reference are evaluated with a comparative study. The equivalent crack width, which can be estimated from the water flow rate, is suggested as a rational evaluation index. Finally, a self-healing performance chart is proposed to comprehensively show the healing performance of cement-based materials.

scholarly journals Experimental Study on the Saturated Compacted Loess Permeability under K0 Consolidation

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Yan-zhou Hao ◽  
Tie-hang Wang ◽  
Xin Jin ◽  
Lei Cheng ◽  
Jiang-le Li
Keyword(s):  
Permeability Coefficient ◽  
Vertical Direction ◽  
Confining Pressure ◽  
Field Analysis ◽  
Dry Density ◽  
Anisotropy Ratio ◽  
Permeability Test ◽  
Permeability Characteristics ◽  
Permeability Anisotropy ◽  
Compacted Loess

This paper investigates the permeability characteristics of compacted loess by focusing on the anisotropy parallel and perpendicular to the compaction. Three tests are conducted on compacted loess: triaxial permeability test under confining pressure consolidation, triaxial permeability test under K0 consolidation, and SEM test. Samples are maintained and tested at different dry densities under saturated conditions. The test results show that the saturated permeability coefficient of compacted loess is exponentially related to the initial dry density under both confining pressure consolidation and K0 consolidation. The fitting equation can estimate the saturated permeability coefficient of compacted loess at different depths. The horizontal saturated permeability coefficient of compacted loess is larger than that in the vertical direction, showing obvious anisotropy. The saturated permeability anisotropy ratio is linearly related to the initial dry density. Comparing and analysing the saturated permeability coefficient, the saturated permeability coefficient of compacted loess under the K0 consolidation condition is smaller than that under the confining pressure consolidation condition. Under the condition of K0 consolidation, the connectivity of vertical and horizontal pores of compacted loess is weakened, the tortuosity is strengthened, and the void ratio is decreased. K0 consolidation makes the flake-, plate-, and needle-like particles in compacted loess rotate continuously parallel to the compaction surface, which enhances the orientation of particles and leads to the saturated permeability anisotropy increase. The research results provide the basis for water field analysis in loess filling engineering.

Permeability Characteristics and Classification of Coal Seams in Nigeria

2009 ◽  
Vol 62-64 ◽  
pp. 357-367
Author(s):  
B.M. Olaleye ◽  
O.O. Onyemaobi ◽  
J.M. Akande
Keyword(s):  
Coal Seam ◽  
Triaxial Compression ◽  
Pressure Gauge ◽  
Water Tank ◽  
Permeability Test ◽  
Coal Seams ◽  
Permeability Characteristics ◽  
Water Infusion ◽  
The Difference

In this work, the permeability characteristics of Nigerian coal seams were determined and these properties were used to investigation the applicability of water infusion in the coal seams to solve coal-mining problems. The experimental work was conducted with Triaxial Compression Machine adapted for the permeability test comprising of Hoek cell, a self- developed water piston, pressure gauge and an overhead water tank. The results of the investigation showed that the permeability measurements of the coals were consistent at the different sites and locations of the coalmines. It also revealed that the difference in coal seam permeability was relatively small in Nigeria.

scholarly journals Pore distribution and classification of loess

2021 ◽  
Vol 261 ◽  
pp. 03002
Author(s):  
Qianqian Liu ◽  
Tiehang Wang
Keyword(s):  
Permeability Coefficient ◽  
Pore Diameter ◽  
Soil Samples ◽  
Permeability Test ◽  
Pore Characteristics ◽  
Permeability Characteristics ◽  
Profound Influence ◽  
Porosity Ratio ◽  
Scanning Electron

The micro-pore characteristics in undisturbed loess have a profound influence on the permeability characteristics. Based on the results of permeability test, it is proved that the permeability coefficient of soil samples with the same porosity ratio is different and the internal characteristics are diversified. The internal pores of undisturbed loess were studied by scanning electron microscopy (SEM). The results show that there are obvious differences in the internal microstructure of the original loess with the same porosity ratio. There are root holes in undisturbed loess, the number and size of which directly affect the value of permeability coefficient. With the increase of pore diameter, the pore size distribution changes gradually, and the influence of small pores is gradually weakened, while the influence of large pores is more obvious. Therefore, only the pore ratio parameter used in engineering can not completely describe the pore characteristics of soil, it is necessary to introduce other microscopic parameters to describe.

scholarly journals 3D Direct Numerical Simulation on the Emergence and Development of Aeolian Sand Ripples

2021 ◽  
Vol 9 ◽  
Author(s):  
Xinghui Huo ◽  
Hongchao Dun ◽  
Ning Huang ◽  
Jie Zhang
Keyword(s):  
Particle Size ◽  
Wind Field ◽  
Numerical Models ◽  
Sand Particle ◽  
Particle Dynamic ◽  
Aeolian Sand ◽  
Holistic View ◽  
Sand Ripples ◽  
Sand Surface

A sand surface subjected to a continuous wind field exhibits a regular ripple surface. These aeolian sand ripples emerge and develop under the coupling effect between the wind field, bed surface topology, and sand particle transportation. Lots of theoretical and numerical models have been established to study the aeolian sand ripples since the last century, but none of them has the capability to directly reproduce the 3D long-term development of them. In this work, a novel numerical model with wind-blow sand and dynamic bedform is established. The emergence and long-term development of sand ripples can be obtained directly. The statistical results extracted from this model tally with those deduced from wind tunnel experiments and field observations. A simplified bed surface particle size description procedure is used in this model, which shows that the particle size distribution makes a very important contribution to sand ripples’ final steady state. This 3D bedform provides a more holistic view on the merging of small bumps before regular ripples’ formation. Analyzing the wind field results reveals an ignored development on the particle dynamic threshold during the bedform deformation.

scholarly journals Experimental Study on Compression and Intrinsic Permeability Characteristics of Municipal Solid Waste

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Gang Zeng ◽  
Jun Ma ◽  
Dan Hu ◽  
Jing Wang
Keyword(s):  
Moisture Content ◽  
Municipal Solid Waste ◽  
Power Function ◽  
Gas Permeability ◽  
Permeability Test ◽  
Intrinsic Permeability ◽  
Test Device ◽  
Logarithmic Model ◽  
Permeability Characteristics ◽  
Gas Compressibility

Compression and gas permeability characteristics of municipal solid waste (MSW) are of great significance to the design, construction, management, and operation of landfill. The objective of this paper was to study the compression and gas permeability characteristics of MSW. A compressing test device and gas permeability test device for MSW were introduced, and laboratory tests were carried out. The test results showed that the final strains at the vertical loads of 100 kPa, 200 kPa, 300 kPa, and 400 kPa were 35.8%, 45.1%, 49.2%, and 55.1%, respectively. The natural logarithm of void ratio and pressure was linearly correlated at different times. Intrinsic permeability measured without considering gas compressibility was smaller than that measured with considering gas compressibility. Intrinsic permeability of MSW decreased with the increase of the inlet pressure. It was suggested that the inlet pressure should be set to 3 kPa for the indoor gas permeability test of MSW. Intrinsic permeability of MSW decreases with the increase of water content and compression displacement. Power function and logarithmic model were suitable for the fitting of permeability and porosity of manually prepared fresh MSW samples, while the K-C model was not suitable. With the increase of moisture content, the coefficient and power index of the power function model decreased gradually. And the slope and intercept of the double logarithmic model also decreased gradually with the increase of moisture content.

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