Characterization of the Layered Pavement by Modelling and Calibration of Resilient Modulus

2014 ◽  
Vol 2 (3) ◽  
pp. 74 ◽  
Author(s):  
Ahmed Ebrahim Abu El-Maaty Behiry
Keyword(s):  
Resilient Modulus

Stiffness Characterization of Asphalt Mixtures with High Recycled Material Content and Recycling Agents

2017 ◽  
Vol 2633 (1) ◽  
pp. 58-68 ◽  
Author(s):  
Fawaz Kaseer ◽  
Fan Yin ◽  
Edith Arámbula-Mercado ◽  
Amy Epps Martin
Keyword(s):  
Resilient Modulus ◽  
Asphalt Mixtures ◽  
Test Results ◽  
Recycled Asphalt ◽  
Reclaimed Asphalt ◽  
Material Content ◽  
Performance Grade ◽  
Recycled Material

Economic and environmental considerations have prompted the use of reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) in asphalt mixtures. However, given the concerns about long-term pavement performance, state departments of transportation (DOTs) tend to limit the quantities of these recycled materials unless certain mixture modifications are made [e.g., use of a softer virgin binder performance grade (PG) and warm-mix asphalt technology, the addition of a recycling agent (RA), or any combination of these modifications]. This study focused on the stiffness characterization of recycled asphalt mixtures with combinations of virgin binder PG, RAP, RAS, and RA. Materials were collected from two field projects in Texas and Indiana, and laboratory specimens were prepared and tested for resilient modulus, and dynamic modulus (| E*|) after short-term oven aging (STOA) and long-term oven aging (LTOA). An RA effectiveness parameter was proposed to quantify the rejuvenating effect of RA, which was defined as the percentage reduction in mixture stiffness for the recycled mixture with RA versus the corresponding control mixture without RA. Furthermore, the | E*| test results were analyzed with a Black Space diagram to discriminate asphalt mixtures with different stiffness and relaxation characteristics. The test results indicated that the incorporation of RA was effective in reducing the stiffness of asphalt mixtures with high recycled material content, but the effectiveness diminished with aging. Moreover, recycled mixtures with a softer and less brittle virgin binder and an RA at a higher dosage showed desirable stiffness and relaxation properties after STOA and LTOA.

Characterization of Subgrade Resilient Modulus for Pavement Design

2011 ◽  
Author(s):  
Z. Hossain ◽  
M. Zaman ◽  
C. Doiron ◽  
P. Solanki
Keyword(s):  
Resilient Modulus ◽  
Pavement Design

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.

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