scholarly journals Generalized Interface Shear Strength Equation for Recycled Materials Reinforced with Geogrids

2021 ◽  
Vol 13 (16) ◽  
pp. 9446
Author(s):  
Artit Udomchai ◽  
Menglim Hoy ◽  
Apichat Suddeepong ◽  
Amornrit Phuangsombat ◽  
Suksun Horpibulsuk ◽  
...  
Keyword(s):  
Shear Strength ◽  
Interface Shear Strength ◽  
Interface Shear ◽  
Recycled Materials ◽  
Reclaimed Asphalt ◽  
Analysis And Design ◽  
Direct Shear Tests ◽  
Base Course Material ◽  
Base Course ◽  
Recycled Material

In this research, large direct shear tests were conducted to evaluate the interface shear strength between reclaimed asphalt pavement (RAP) and kenaf geogrid (RAP–geogrid) and to also assess their viability as an environmentally friendly base course material. The influence of factors such as the gradation of RAP particles and aperture sizes of geogrid (D) on interface shear strength of the RAP–geogrid interface was evaluated under different normal stresses. A critical analysis was conducted on the present and previous test data on geogrids reinforced recycled materials. The D/FD, in which FD is the recycled materials’ particle content finer than the aperture of geogrid, was proposed as a prime parameter governing the interface shear strength. A generalized equation was proposed for predicting the interface shear strength of the form: α = a(D/FD) + b, where α is the interface shear strength coefficient, which is the ratio of the interface shear strength to the shear strength of recycled material, and a and b are constants. The constant values of a and b were found to be dependent upon types of recycled material, irrespective of types of geogrids. A stepwise procedure to determine variable a, which is required for analysis and design of geogrids reinforced recycled materials in roads with various gradations was also suggested.

Some Observations on Soil-Pipe Interface Shear Strength in Direct Shear Under Low Effective Normal Stresses and Large Displacements

2016 ◽  
Author(s):  
Ruslan S. Amarasinghe ◽  
Dharma Wijewickreme ◽  
Hisham T. Eid
Keyword(s):  
Shear Strength ◽  
Accurate Determination ◽  
Direct Shear ◽  
Normal Stresses ◽  
Interface Shear Strength ◽  
Interface Shear ◽  
Fine Grained ◽  
Direct Shear Tests ◽  
Macro Scale ◽  
Soil Pipe

Experimental work is undertaken at the University of British Columbia (UBC) to study the soil-pipe interface shear strength at levels of shear displacements and effective normal stresses typically encountered in offshore soil-pipe interaction problems. A macro-scale interface direct shear apparatus having a test specimen footprint of 1.72 m × 1.75 m was designed and built for this purpose. The apparatus is capable of testing various soil-pipe interfaces under effective normal stresses in the range of 3 kPa to 6 kPa. A maximum shear displacement of 1.2 m is achievable at rates ranging from 0.1 μm/s to 1 mm/s. Sensors mounted at the interface enable the accurate determination of the effective normal stress at the interface when fully saturated fine-grained soils are tested. This paper presents some observations arising from a series of interface direct shear tests involving fine-grained soils of different plasticity against bare and epoxy coated steel surfaces.

scholarly journals Interface shear strength of polypropylene pipeline coatings and granular materials at low stress level

2019 ◽  
Vol 92 ◽  
pp. 13010
Author(s):  
Lawrence W De Leeuw ◽  
Andrea Diambra ◽  
Matt S Dietz ◽  
George Mylonakis ◽  
Henry Milewski
Keyword(s):  
Grain Size ◽  
Shear Strength ◽  
Stress Level ◽  
Interfacial Strength ◽  
Interface Shear Strength ◽  
Interface Shear ◽  
Direct Shear Tests ◽  
Perfectly Plastic ◽  
Effective Roughness ◽  
Wide Range

A range of sands were tested in direct and interface shear at very low stresses to determine the interface shear strength of polypropylene pipeline coating counterfaces and to evaluate interface efficiency. Polypropylene has a wide range of applications as a coating material in the offshore environment, so quantification of interfacial strength is an important component for geotechnical design. Direct shear tests show classic peak-postpeak stress-displacement and stress-dilatancy behaviour whereas interface tests show an elastic, perfectly plastic type behaviour for both loose and dense samples with no appreciable volumetric response. Interface efficiencies generally range between 0.3 and 0.7 dependent on both grain size and stress level. Normalised roughness is used to relate the surface roughness to the grain size and shows that the greater interface strength with smaller grained sands can be explained by their greater effective roughness. The relationship between stress ratio and normalised roughness for sand-polypropylene resembles established relationships for sand-steel interfaces.

scholarly journals Asperities effect on polypropylene & polyester geotextile-geomembrane interface shear behaviour

2019 ◽  
Vol 92 ◽  
pp. 13017
Author(s):  
Daniel Adeleke ◽  
Denis Kalumba ◽  
Johnny Oriokot
Keyword(s):  
Shear Strength ◽  
Engineering Application ◽  
Friction Angle ◽  
Strength Properties ◽  
Shear Behaviour ◽  
Percentage Increase ◽  
Interface Shear Strength ◽  
Interface Shear ◽  
Direct Shear Tests ◽  
Shear Characteristics

The summary of this paper is focused on the result of a study that used quantitative measures of surface texture as the basis for examining the effects of asperities on the shear characteristics of geotextile-geomembrane interfaces. About 30 large direct shear tests were conducted to evaluate the geotextile-geomembrane interface shear strength properties. The results indicated a non-linear failure envelopes and strain softening behaviour at a normal stress range of 50 – 400 kPa. For most interface tested, the polyester-geotextiles resulted in higher shear strength as compared with polypropylene-geotextiles. Also, the polyester and polypropylene geotextile interface with the high asperity geomembrane produces a similar percentage increase in friction angle at the residual state. For textured geomembranes interfaced with both geotextile, polyester geotextile exhibited relatively less time before failure. Also, asperity height has a more pronounced effect than asperity density on the residual interface shear strength. The outcome of this study would provide a recommendation and guide that can lead to an improved basis for geosynthetics selection in various engineering application.

scholarly journals Investigation of soil-steel interface behavior of Iraqi soil by direct shear apparatus

2018 ◽  
Vol 162 ◽  
pp. 01003
Author(s):  
Omar Al-Emami
Keyword(s):  
Shear Strength ◽  
Steel Surface ◽  
Silty Sand ◽  
Direct Shear ◽  
Interface Shear Strength ◽  
Engineering Structures ◽  
Interface Shear ◽  
Analysis And Design ◽  
Steel Surfaces ◽  
Direct Shear Apparatus

Soil - structure interaction is an important theme observed in many civil engineering structures like fondations. The interface shear strength plays a significant role in the analysis and design of many structures constructed above or under the ground. In this study, a total of 28 specimens were tested at vertical stresses of 100, 200, and 400 kPa using direct shear apparatus under consolidated drained condition. A silty sand soil, as per USCS classification system was prepared in the laboratory at different water contents (4.5%, 8.8%, and 12.5%) and voids ratios (0.4, 0.6, 0.8, and 1). The frictional resistance of this soil was measured. The soil samples were also sheared against three steel surfaces of different textures (smooth, moderate-rough, and rough). The experimental results showed that the steel surface texture is an effective factor in soil-steel interface shear strength. The interface shear strength of the rough steel surface was found higher than smooth and semi-rough steel surfaces. In addition to the surface roughness, the water content and void ratio also play important roles in interface shear strength.

Influence of revision arthroplasty on bone/cement interface shear strength

1987 ◽  
Vol 20 (8) ◽  
pp. 824
Author(s):  
J.E. Bechtold ◽  
Y. Dohmae ◽  
R.E. Sherman ◽  
R.B. Gustilo
Keyword(s):  
Shear Strength ◽  
Bone Cement ◽  
Revision Arthroplasty ◽  
Interface Shear Strength ◽  
Interface Shear ◽  
Cement Interface

scholarly journals Skewness and Kurtosis: Important Parameters in the Characterization of Dental Implant Surface Roughness—A Computer Simulation

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Karl Niklas Hansson ◽  
Stig Hansson
Keyword(s):  
Surface Roughness ◽  
Shear Strength ◽  
Roughness Parameter ◽  
Interface Shear Strength ◽  
Interface Shear ◽  
Implant Surface ◽  
Bone Response ◽  
Dental Implant Surface ◽  
Skewness And Kurtosis

The surface roughness affects the bone response to dental implants. A primary aim of the roughness is to increase the bone-implant interface shear strength. Surface roughness is generally characterized by means of surface roughness parameters. It was demonstrated that the normally used parameters cannot discriminate between surfaces expected to give a high interface shear strength from surfaces expected to give a low interface shear strength. It was further demonstrated that the skewness parameter can do this discrimination. A problem with this parameter is that it is sensitive to isolated peaks and valleys. Another roughness parameter which on theoretical grounds can be supposed to give valuable information on the quality of a rough surface is kurtosis. This parameter is also sensitive to isolated peaks and valleys. An implant surface was assumed to have a fairly well-defined and homogenous “semiperiodic” surface roughness upon which isolated peaks were superimposed. In a computerized simulation, it was demonstrated that by using small sampling lengths during measurement, it should be possible to get accurate values of the skewness and kurtosis parameters.

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