Use of Cyclic Direct Tension Tests and Digital Imaging Analysis to Evaluate Moisture Susceptibility of Warm-Mix Asphalt Concrete

2013 ◽  
Vol 2372 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Jong-Sub Lee ◽  
Jae-Jun Lee ◽  
Soo-Ahn Kwon ◽  
Y. Richard Kim
Keyword(s):  
Digital Imaging ◽  
Asphalt Concrete ◽  
Warm Mix Asphalt ◽  
Imaging Analysis ◽  
Direct Tension ◽  
Moisture Susceptibility ◽  
Tension Tests

Watertightness, cracking resistance, and self-healing of asphalt concrete used as a water barrier in dams

2013 ◽  
Vol 50 (3) ◽  
pp. 275-287 ◽  
Author(s):  
Yingbo Zhang ◽  
Kaare Höeg ◽  
Weibiao Wang ◽  
Yue Zhu
Keyword(s):  
Asphalt Concrete ◽  
Leakage Rate ◽  
Strain Rates ◽  
Self Healing ◽  
Test Results ◽  
Direct Tension ◽  
Coefficient Of Permeability ◽  
Tension Tests ◽  
Laboratory Test Results ◽  
Cracked Specimens

The coefficient of permeability of hydraulic asphalt concrete is in the range 10−8–10−10 cm/s. Laboratory test results show that triaxial specimens in axial compression can undergo axial strains up to 18% without any significant increase in permeability until approaching the compressive strength. For temperatures between 5 and 20 °C and strain rates between 2 × 10−3%/s and 5 × 10−3%/s, conventional hydraulic asphalt concrete can tolerate 1%–3% tensile strains before cracking in direct tension tests and strains up to 3%–4% in bending. At 20 °C the tensile and bending strains at cracking are 2–4 times higher than those at 0 °C, and at −20 °C they are approximately 0.2% and 0.8%, respectively. Asphalt concrete possesses pronounced crack self-healing properties. In the experiments, the crack leakage rate dropped 1–4 orders of magnitude within a few hours and the cracked specimens regained 55% of the intact tensile strength after only 1 day of self-healing. In summary, the comprehensive series of laboratory tests documents that asphalt concrete has characteristics that make the material extremely well suited for use in impervious barriers in dams, and the test results reported herein can be of great use in barrier design.

Experimental Evaluation of Moisture Damage and Rutting Resistance for SBS Modified Warm Mix Asphalt Incorporating Recycled Asphalt Concrete

2021 ◽  
Vol 904 ◽  
pp. 464-469
Author(s):  
Mohammed Qadir Ismael
Keyword(s):  
Tensile Strength ◽  
Asphalt Concrete ◽  
Experimental Evaluation ◽  
Asphalt Binder ◽  
Stability Index ◽  
Warm Mix Asphalt ◽  
Recycled Asphalt ◽  
Moisture Susceptibility ◽  
Rutting Resistance ◽  
Styrene Butadiene

The efforts embedded in this paper have been devoted to designing, preparing, and testing warm mix asphalt (WMA) mixtures and comparing their behavior against traditional hot mix asphalt mixtures. For WMA preparation, the Sasobit wax additive has been added to a 40/50 asphalt binder with a concentration of 3%. An experimental evaluation has been performed by conducting the Marshall together with volumetric properties, indirect tensile strength, and wheel tracking tests to acquire the tensile strength ratio (TSR), retained stability index (RSI), and rut depth. It was found that the gained benefit of reduction in mixing and compaction temperatures was reversely associated with a noticeable decline in Marshall properties and moisture susceptibility indices designated by TSR, and RSI, and even the rut resistance was adversely affected. Modification of WMA mixtures by 3% of Styrene-Butadiene-Styrene (SBS) polymer coupled with replacement of virgin ingredient by 50% of recycled asphalt concrete granted a 20% and 15% growth in Marshall stability and tensile strength, respectively. Moreover, both TSR and IRS indices have risen to 87% and 90%, respectively associated with a 39% increase in rutting resistance ability.

Viscoelastic Properties of Field-Aged Cores

2013 ◽  
Vol 723 ◽  
pp. 551-556
Author(s):  
Ling Meng
Keyword(s):  
Asphalt Concrete ◽  
Viscoelastic Properties ◽  
Hot Mix Asphalt ◽  
Asphalt Mixture ◽  
Warm Mix Asphalt ◽  
Tension Test ◽  
Asphalt Mixtures ◽  
Direct Tension ◽  
Direct Tension Test ◽  
Aged Asphalt

Nowadays, engineers begin to pay more attention on field-aged asphalt concrete cores because they have more reality than the lab-made cores and the results can tell what happened to the pavement. However, it is not accurate to estimate the full asphalt mixture because as usual the pavement engineers can only extract the binder from it, not the mixture. Now there is a newly developed way to analysis the data more accurately using the Direct Tension Test. Because the field aged asphalt mixtures are not aged uniformly with the pavement depth because of various reasons, there is a modulus gradient going through deeply through the asphalt layer and usually the stiffest layer is the surface because normally the surface is more aged. A method has been developed to analysis this behavior. Tests are both taken on field cores which are Hot Mix Asphalt (HMA) and Warm Mix Asphalt (WMA). During the research, the authors found that it is both applicable for all the field cores. More information about this method and tests are detailed in the following paragraphs.

Effects of Asphalt Foaming on Damage Characteristics of Foamed Warm Mix Asphalt

2021 ◽  
pp. 036119812199782
Author(s):  
Biswajit K. Bairgi ◽  
Md Amanul Hasan ◽  
Rafiqul A. Tarefder
Keyword(s):  
Permanent Deformation ◽  
Warm Mix Asphalt ◽  
Creep Recovery ◽  
Deformation Model ◽  
Contact Method ◽  
Moisture Susceptibility ◽  
Viscoelastic Continuum Damage ◽  
Foamed Asphalt ◽  
Flexural Beam ◽  
Wheel Tracking

In the asphalt foaming process, the foaming water content (FWC) controls the formation and characteristics of water bubbles. These water bubbles are expected to be expelled from the foamed warm mix asphalt (WMA) during mixing and compaction. However, foaming water may not be completely expelled, rather some of the microbubbles may be trapped in the foamed WMA even after compaction. These microbubbles, or undissipated water, can diffuse over time and cause damage to the foamed WMA. To this end, this study has determined the effects of foaming on the fatigue, moisture damage, and permanent deformation characteristics of foamed WMA. Foamed asphalt and mixtures were designed with varying FWCs and they were tested using linear amplitude sweep, multiple stress creep recovery, four-point flexural beam, and Hamburg wheel tracking tests. Primarily, asphalt foaming dynamics were assessed with a laser-based non-contact method. A simplified viscoelastic continuum damage concept and a three-phase permanent deformation model were used for damage evaluation. The study reveals that foaming softens the binder, which results in slightly higher rutting and moisture susceptibility, though an equivalent or slightly improved fatigue characteristic compared with the regular hot mix asphalt.

Evaluation of Moisture Susceptibility Minimization Strategies for Warm-Mix Asphalt: Case Study

2016 ◽  
Vol 28 (2) ◽  
pp. 05015002 ◽  
Author(s):  
Lorena Garcia Cucalon ◽  
Fan Yin ◽  
Amy Epps Martin ◽  
Edith Arambula ◽  
Cindy Estakhri ◽  
...  
Keyword(s):  
Warm Mix Asphalt ◽  
Moisture Susceptibility

scholarly journals Digital Imaging Analysis with Fractal Dimension in Oral Leukoplakia

2017 ◽  
Vol 2 (1) ◽  
pp. 1-5
Author(s):  
CH Reddy ◽  
M Anitha ◽  
A Feroz ◽  
L Chandrashekar ◽  
R Sudarshan ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Digital Imaging ◽  
Oral Leukoplakia ◽  
Imaging Analysis
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