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.

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.

Field and Laboratory Characterization of Subgrade Resilient Modulus for Pavement Mechanistic-Empirical Pavement Design Guide Application

2020 ◽  
Vol 2674 (8) ◽  
pp. 921-930
Author(s):  
Kazi Moinul Islam ◽  
Sarah Gassman ◽  
Md Mostaqur Rahman
Keyword(s):  
South Carolina ◽  
Resilient Modulus ◽  
Pavement Design ◽  
Coarse Grained ◽  
Triaxial Tests ◽  
Laboratory Characterization ◽  
Design Guide ◽  
Repeated Load ◽  
Repeated Load Triaxial

The resilient modulus (MR) of subgrade material is an important parameter in pavement design using the Mechanistic-Empirical Pavement Design Guide (MEPDG) and has a significant influence on pavement performance. MR can be obtained indirectly from falling weight deflectometer (FWD) data using a back-calculation tool (i.e., AASHTOWare 2017) or from empirical correlations with soil index properties. MR can also be obtained directly using repeated load triaxial tests (AASHTO T 307-99, 2017). In this study, the field test program included FWD tests and soil sampling. These field tests were performed on six asphalt pavement sections in South Carolina, U.S., to estimate the MR of the subgrade soil. This study involved extensive laboratory characterization of subgrade soils collected from underneath the pavement sections. Laboratory characterization included index tests (sieve analysis, Atterberg limits, specific gravity, moisture content, and standard Proctor density tests) on bulk samples and repeated load triaxial tests on thin-walled tube samples to obtain a direct measure of MR. Results show that the MR values found from the FWD data have similar trends to the laboratory-measured MR values. However, results from lab testing were 33%–75% lower than the back-calculated MR. Laboratory-measured MR, and back-calculated MR were used to determine a C-factor of 0.33, 0.25, and 0.29 for coarse-grained, fine-grained, and all types of soils, respectively. This parameter can be used to estimate resilient modulus for MEPDG Level 2 design inputs across South Carolina and similar geologic regions. The research studies will be facilitated by the local calibration and implementation of the MEPDG.

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.

Repeated Load Triaxial Tests on a Dolomite Ballast

1978 ◽  
Vol 104 (7) ◽  
pp. 1013-1029
Author(s):  
Gerald Patrick Raymond ◽  
David R. Williams
Keyword(s):  
Triaxial Tests ◽  
Repeated Load ◽  
Repeated Load Triaxial

scholarly journals Development of a Correlation between the Resilient Modulus and CBR Value for Granular Blends Containing Natural Aggregates and RAP/RCA Materials

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Muhammad Arshad
Keyword(s):  
Statistical Analysis ◽  
Resilient Modulus ◽  
Recycled Concrete ◽  
Experimental Results ◽  
Triaxial Tests ◽  
Concrete Aggregate ◽  
Reclaimed Asphalt ◽  
Serviceable Life ◽  
Natural Aggregates ◽  
Repeated Load Triaxial

Limited supplies of natural aggregates for highway construction, in addition to increasing processing costs, time, and environmental concerns, have led to the use of various reclaimed/recycled materials. Reclaimed asphalt pavement (RAP) and recycled concrete aggregate (RCA) have prospective uses in substantial amounts in base and subbase layers of flexible pavement in order to overcome the increasing issue of a shortage of natural aggregates. This research presents the development of an empirical model for the estimation of resilient modulus value (MR) on the basis of CBR values using experimental results obtained for 52 remoulded granular samples containing natural aggregates, RCA, and RAP samples. Statistical analysis of the suggested model shows promising results in terms of its strength and significance when t-test was applied. Additionally, experimental results also show that MR value increases in conjunction with an increase in RAP contents, while the trend for the CBR value is the opposite. Statistical analysis of simulation results using PerRoad and KenPave demonstrates that addition of RAP contents in the subbase layer of flexible pavements significantly improves its performance when considering resistance against rutting and fatigue. However, results of repeated load triaxial tests show that residual accumulative strain under a certain range of loading conditions increases substantially due to the addition of RAP materials, which may be disadvantageous to the serviceable life of the whole pavement structure.

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.

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