Repeated compressive loading of a sand

1979 ◽  
Vol 16 (4) ◽  
pp. 798-802 ◽  
Author(s):  
P. N. Gaskin ◽  
G. P. Raymond ◽  
F. Y. Addo-Abedi ◽  
J. S. Lau
Keyword(s):  
Threshold Stress ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Compressive Loading ◽  
Triaxial Tests ◽  
Failure Strength ◽  
Stress Cycles ◽  
Repeated Load ◽  
Static Failure

Twelve repeated load drained triaxial tests to at least 105 cycles on a sand are reported. A threshold stress of about 50% of the static failure strength was found. Below the threshold stress, the permanent deformation and resilient modulus reached constant values. Above the threshold stress, the permanent deformation began to increase rapidly and the resilient modulus to decrease as the number of stress cycles increased. The importance of keeping the traffic stress in the pavement below the threshold stress is outlined.

Repeated compressive loading of Leda clay

1979 ◽  
Vol 16 (1) ◽  
pp. 1-10 ◽  
Author(s):  
G. P. Raymond ◽  
P. N. Gaskin ◽  
F. Y. Addo-Abedi
Keyword(s):  
Stress Level ◽  
Threshold Stress ◽  
Resilient Modulus ◽  
Compressive Loading ◽  
Repeated Load ◽  
Leda Clay

Repeated load drained tests on Leda clay, as related to subgrade performance, are reported. A threshold stress divided the performance into failing and stable specimens. For the stable specimens the resilient modulus attained equilibrium at about 105 cycles but varied with stress level. Permanent strains continued even at low stresses.

scholarly journals Repeated Load Triaxial Testing of Recycled Excavation Materials Blended with Recycled Phyllite Materials

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 621
Author(s):  
Solomon Adomako ◽  
Christian John Engelsen ◽  
Rein Terje Thorstensen ◽  
Diego Maria Barbieri
Keyword(s):  
Mechanical Performance ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Economic Benefits ◽  
Base Layer ◽  
Triaxial Tests ◽  
Similar Response ◽  
Weak Rocks ◽  
Repeated Load ◽  
Repeated Load Triaxial

Recycled Excavation Materials (REM) are becoming viable alternative construction resources due to their economic benefits. However, REM may be composed of weak rocks, e.g., phyllites, limiting the use in a base layer. The present paper attempts to further the knowledge of the mechanical performance of REM by performing Repeated Load Triaxial Tests (RLTT). REM are mixed with Recycled Phyllite Materials (RPM) in systematic blends of 0%, 25%, 50%, and 100%. The batches’ resilient modulus (MR) and permanent deformation (PD) characteristics were assessed to establish the maximum RPM allowed into REM while maintaining the required performance. Hicks and Monismith’s and Uzan’s models were used to characterize the stiffness behavior. A wide variation in the stiffness between the two materials was observed. Batches comprised of 0% RPM–100% REM and 25% RPM–75% REM showed high stiffness performance. The Coulomb model assessed the PD behavior, and the results showed a similar response for all batches. Unlike the stiffness, blended mixtures did not show sensitivity to increased RPM content in the PD. This study may help end-users to understand the performance of REM given the documented threshold on the allowable quantity of RPM in REM.

Numerical and Graphical Method to Assess Permanent Deformation Potential for Repeated Compressive Loading of Asphalt Mixtures

2000 ◽  
Vol 1723 (1) ◽  
pp. 150-158 ◽  
Author(s):  
Rajesh K. Bhairampally ◽  
Robert L. Lytton ◽  
Dallas N. Little
Keyword(s):  
Strain Energy ◽  
Graphical Method ◽  
Permanent Deformation ◽  
Compressive Loading ◽  
Hydrated Lime ◽  
Numerical Approach ◽  
Empirical Models ◽  
Asphalt Mixtures ◽  
Deformation Potential ◽  
Repeated Load

Repeated-load permanent deformation testing has long been a popular way to characterize the performance of asphalt mixtures and to account for damage that leads to rutting. A number of empirical models have been used to fit repeated-load permanent deformation data. One such model, developed by Tseng and Lytton in 1989, fits permanent deformation data of most asphalt mixtures well. However, some mixtures exhibit a rate of damage that is in excess of that predicted by the 1989 Tseng and Lytton model. A numerical adaptation of the Tseng and Lytton empirical model is presented that readily characterizes such damage-susceptible mixtures. The excessive rate of damage is explained and reconciled in terms of plastic work theory and dissipated strain energy. The numerical approach is used to demonstrate the corrective effects of two types of additives to the mixtures: a recycled coproduct and hydrated lime.

scholarly journals An Evaluation of the Resilient Modulus and Permanent Deformation of Unbound Mixtures of Granular Materials and Rubber Particles from Scrap Tyres to Be Used in Subballast Layers

2016 ◽  
Author(s):  
Carlos Hidalgo Sgnes
Keyword(s):  
Granular Materials ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Waste Material ◽  
Triaxial Tests ◽  
Rubber Content ◽  
Cyclic Triaxial ◽  
Cyclic Triaxial Tests ◽  
Vibration Attenuation ◽  
Rubber Particles

Over the last years rubber from scrap tyres has been reused in different civil works such as road embankments and railway platforms due to its resilient properties, low degradation and vibration attenuation. Unfortunately, this issue is still scarce. For instance, in Spain about 175.000 tonnes of scrap tyres were collected in 2014, of which only 0.6% were reused in civil works. Aiming to contribute to the reutilisation of large quantities of this waste material, this paper focuses on the analysis of unbound mixtures of granular materials with different percentages of rubber particles to be used as subballast layers. Mixtures are tested under cyclic triaxial tests so as to obtain their resilient modulus and evaluate their permanent deformations. It is found that as the rubber content increases, the resilient modulus decreases and the permanent deformation increases. Taking into account the usual loads transmitted to the subballast layer, the optimum rubber content that does not compromise the behaviour of the mixture is set in a range between 2.5% and 5% in terms of weight.DOI: http://dx.doi.org/10.4995/CIT2016.2016.4231

Geogrid Stabilization of Unbound Aggregates Evaluated Through Bender Element Shear Wave Measurement in Repeated Load Triaxial Testing

2020 ◽  
Vol 2674 (3) ◽  
pp. 113-125
Author(s):  
Mingu Kang ◽  
Joon Han Kim ◽  
Issam I. A. Qamhia ◽  
Erol Tutumluer ◽  
Mark H. Wayne
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Resilient Modulus ◽  
Triaxial Tests ◽  
Triaxial Testing ◽  
Bender Element ◽  
Wave Measurement ◽  
Repeated Load ◽  
Repeated Load Triaxial

This paper describes the use of the bender element (BE) shear wave measurement technology for quantifying the effectiveness of geogrid stabilization of unbound aggregate materials with improved mechanical properties from repeated load triaxial testing. Crushed stone aggregate specimens were prepared with three different gradations, that is, upper bound (UB), mid-range engineered (ENG), and lower bound, according to the dense graded base course gradation specification in Illinois. The specimens were compacted at modified Proctor maximum dry densities and optimum moisture contents. Two geogrids with different triaxial aperture sizes were placed at specimen mid-height, and unstabilized specimens with no geogrid were also prepared for comparison. To measure shear wave velocity, three BE pairs were placed at different heights above geogrid. Repeated load triaxial tests were conducted following the AASHTO T307 standard resilient modulus test procedure, while shear wave velocity was measured from the installed BE pairs. After initial specimen conditioning, and at low, intermediate, and high applied stress states, both the resilient moduli and accumulated permanent strains were determined to relate to the geogrid local stiffening effects in the specimens quantified by the measured shear wave velocities. The resilient modulus and shear wave velocity trends exhibited a directly proportional relationship, whereas permanent strain and shear wave velocity values were inversely related. The enhancement ratios calculated for the geogrid stabilized over the unstabilized specimens showed significant improvements in mechanical behavior for the UB and ENG gradations, and a maximum enhancement was achieved for the engineered gradation specimens stabilized with the smaller aperture geogrid.

Resilient Moduli of Treated Clays from Repeated Load Triaxial Test

2003 ◽  
Vol 1821 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Anand J. Puppala ◽  
Aravinda M. Ramakrishna ◽  
Laureano R. Hoyos
Keyword(s):  
Clayey Soil ◽  
Resilient Modulus ◽  
Triaxial Tests ◽  
Cement Type ◽  
Repeated Load ◽  
Resilient Response ◽  
Type V ◽  
Deviatoric Stresses ◽  
The Impact ◽  
Repeated Load Triaxial

Three chemical stabilization methods—sulfate resistant cement (Type V), low-calcium fly-ash (Class F) mixed with sulfate resistant cement (Type V), and ground granulated blast furnace slag—were used in a series of repeated load triaxial tests on clayey soil to assess the effectiveness of these three stabilizers in enhancing resilient modulus ( MR) properties of the soil. MR results were measured from repeated load triaxial tests conducted on both control and treated soils at optimum moisture content levels. Test results were analyzed to understand the potentials of each stabilizer on MR response of the soils and to study the effects of confining and deviatoric stresses on resilient response of the treated soils. Mechanisms for MR enhancements in treated soils were developed, and a series of flexible pavement design exercises was conducted to evaluate the impact of each stabilizer on the design thickness of the asphalt surface layer of pavements.

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