scholarly journals Improved Adhesion Bond between Asphalt Binder-Aggregate as Indicator to Reduced Moisture Damage

2021 ◽  
Vol 1973 (1) ◽  
pp. 012059
Author(s):  
Ehsan A. Hasan ◽  
Yasameen Hadi Abed ◽  
Abdulhaq H. Abedali Al-Haddad
Keyword(s):  
Asphalt Binder ◽  
Moisture Damage ◽  
Adhesion Bond

Effectiveness of Loaded Wheel Tracking Test to Ascertain Moisture Susceptibility of Asphalt Mixtures

2021 ◽  
pp. 036119812110363
Author(s):  
Moses Akentuna ◽  
Louay N. Mohammad ◽  
Sanchit Sachdeva ◽  
Samuel B. Cooper ◽  
Samuel B. Cooper
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Moisture Damage ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Creep Recovery ◽  
Moisture Susceptibility ◽  
Freeze Thaw ◽  
Wheel Tracking ◽  
Mixture Samples

Moisture damage of asphalt mixtures is a major distress affecting the durability of asphalt pavements. The loaded wheel tracking (LWT) test is gaining popularity in determining moisture damage because of its ability to relate laboratory performance to field performance. However, the accuracy of LWT’s “pass/fail” criteria for screening mixtures is limited. The objective of this study was to evaluate the capability of the LWT test to identify moisture susceptibility of asphalt mixtures with different moisture conditioning protocols. Seven 12.5 mm asphalt mixtures with two asphalt binder types (unmodified PG 67-22 and modified PG 70-22), and three aggregate types (limestone, crushed gravel, and a semi-crushed gravel) were utilized. Asphalt binder and mixture samples were subjected to five conditioning levels, namely, a control; single freeze–thaw-; triple freeze–thaw-; MiST 3500 cycles; and MiST 7000 cycles. Frequency sweep at multiple temperatures and frequencies, and multiple stress creep recovery tests were performed to evaluate asphalt binders. LWT test was used to evaluate the asphalt mixture samples. Freeze–thaw and MiST conditioning resulted in an increase in stiffness in the asphalt binders as compared with the control. Further, freeze–thaw and MiST conditioning resulted in an increase in rut depth compared with the control asphalt mixture. The conditioning protocols evaluated were effective in exposing moisture-sensitive mixtures, which initially showed compliance with Louisiana asphalt mixture design specifications.

scholarly journals Evaluating the Surface Free Energy and Moisture Sensitivity of Warm Mix Asphalt Binders Using Dynamic Contact Angle

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Muhammad Rafiq Kakar ◽  
Meor Othman Hamzah ◽  
Mohammad Nishat Akhtar ◽  
Junita Mohamad Saleh
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Hot Mix Asphalt ◽  
Asphalt Binder ◽  
Moisture Damage ◽  
Warm Mix Asphalt ◽  
Work Of Adhesion ◽  
Moisture Sensitivity ◽  
Modified Binders ◽  
Production Temperature

From the environmental conservation perspective, warm mix asphalt is more preferable compared to hot mix asphalt. This is because warm mix asphalt can be produced and paved in the temperature range 20–40°C lower than its equivalent hot mix asphalt. In terms of cost-effectiveness, warm mix asphalt can significantly improve the mixture workability at a lower temperature and thus reduce greenhouse gas emissions, to be environment friendly. However, the concern, which is challenging to warm mix asphalt, is its susceptibility to moisture damage due to its reduced production temperature. This may cause adhesive failure, which could eventually result in stripping of the asphalt binder from the aggregates. This research highlights the significance of Cecabase warm mix additive to lower the production temperature of warm mix asphalt and improvise the asphalt binder adhesion properties with aggregate. The binders used in the preparation of the test specimen were PG-64 and PG-76. The contact angle values were measured by using the dynamic Wilhelmy plate device. The surface free energy of Cecabase-modified binders was then computed by developing a dedicated algorithm using the C++ program. The analytical measurements such as the spreadability coefficient, work of adhesion, and compatibility ratio were used to analyze the results. The results inferred that the Cecabase improved the spreadability of the asphalt binder over limestone compared to the granite aggregate substrate. Nevertheless, the Cecabase-modified binders improved the work of adhesion. In terms of moisture sensitivity, it is also evident from the compatibility ratio indicator that, unlike granite aggregates, the limestone aggregates were less susceptible to moisture damage.

Comparison of Coarse Matrix High Binder and Dense-Graded Hot-Mix Asphalt

1997 ◽  
Vol 1590 (1) ◽  
pp. 108-117 ◽  
Author(s):  
Richard P. Izzo ◽  
Joe W. Button ◽  
Maghsoud Tahmoressi
Keyword(s):  
Tensile Strength ◽  
Creep Test ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Asphalt Binder ◽  
Moisture Damage ◽  
Static Creep ◽  
Indirect Tensile ◽  
Effects Of Aging ◽  
Static Creep Test

Coarse matrix high binder (CMHB) is a gap-graded hot mix consisting of a large proportion of coarse aggregate with an asphalt binder-filler mastic. CMHB and dense-graded mixtures were compared in terms of their resistance to rutting (permanent deformation), moisture damage, aging, and water permeability. A static creep test was performed to evaluate relative rutting susceptibility. Moisture damage was assessed with the tensile strength ratio (TSR) and a boiling-water test. The effects of aging were evaluated with indirect tensile strength and resilient modulus testing. Penetration and complex shear modulus ( G*) of the recovered, aged asphalt were measured. Permeability was determined with Darcy's Law for flow through saturated, porous media. The static creep test did not indicate that CMHB mixtures were consistently more resistant to rutting in comparison with dense-graded mixtures. CMHB mixtures were found to be more resistant to moisture damage, which was indicated by higher TSR values and less visible stripping than corresponding dense-graded mixtures. The dense-graded mixtures exhibited higher resilient moduli and indirect tensile strengths after short-term and long-term aging. Penetration of binder extracted from aged CMHB mixtures was greater than that from dense-graded mixtures. Binder extracted from aged dense-graded mixtures exhibited higher G* values. The permeability of CMHB mixtures was greater than that of the dense-graded mixtures with comparable air voids.

Behavior of Carbon Nano-Tubes (CNTs) as Modifier to Resist Aging and Moisture Damage in Asphalt

2020 ◽  
Vol 10 ◽  
Author(s):  
Md Arifuzzaman ◽  
R. A. Tarefder ◽  
Muhammad Saiful Islam
Keyword(s):  
Asphalt Binder ◽  
Moisture Damage ◽  
Crumb Rubber ◽  
Outdoor Environment ◽  
Adhesion Forces ◽  
Modified Asphalt ◽  
Road Pavement ◽  
Carbon Nano Tubes ◽  
Styrene Butadiene ◽  
Sbs Modified Asphalt

Background: Moisture damage and aging take place together in asphalt binder as it is on road-pavement in service life and therefore quite difficult to overcome. Various techniques, such as crumb rubber, fibres, etc., have been applied to improve the behaviour of asphalt materials Use of nano materials was found as one of the effective techniques to develop temperature performances of asphalt binder. Methods: This study investigated moisture damage and aging of asphalt binder mixing with the carbon nano tubes (CNTs) using Atomic Force Microscopy (AFM). The base binder was primarily modified with 4% SBS polymer. Later on, CNTs were mixied in different percentages (i.e., 0.5%, 1%, and 1.5%) by weight with the 4% styrene–butadiene–styrene (SBS) modified binders. A special functionalized (-NH3) AFM probe with spring constant 3.44 N/m was utilised to complete the study. Results: The results were compared with 4% SBS modified asphalt with and without CNT addition.The adhesion forces of dry samples were found smaller as compared to wet and aged asphalt samples of with and without CNT. However, the adhesion forces of wet and aged samples with investigated percentage of CNT performed considerably better than those without CNT. Conclusion: This result clearly indicated significant improvement of asphalt to overcome moisture damage and aging owing to exposure in outdoor environment as a paving material. This study recommends any dosage (i.e., 0.5 to 1.5% by weight) of CNT with 4% SBS modified asphalt to resist moisture damage and aging in field.

Evaluation of Rheological and Moisture Damage Properties of Crumb Rubber–Modified Asphalt Binder

2019 ◽  
Vol 8 (1) ◽  
pp. 20190045 ◽  
Author(s):  
Dharamveer Singh ◽  
Vinamra Mishra ◽  
Shashi Bhushan Girimath ◽  
Aditya Kumar Das ◽  
Bharat Rajan
Keyword(s):  
Asphalt Binder ◽  
Moisture Damage ◽  
Crumb Rubber ◽  
Modified Asphalt ◽  
Modified Asphalt Binder

scholarly journals Effects of Asphalt Binder Modifying with Polypropylene on Moisture Susceptibility of Asphalt Mixtures with Thermodynamically Concepts

2018 ◽  
Author(s):  
Gholam Hossein Hamedi ◽  
Ali Reza Azarhoosh ◽  
Mojtaba Khodadadi
Keyword(s):  
Free Energy ◽  
Asphalt Binder ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Test Results ◽  
Cohesion Strength ◽  
Adhesion Bond ◽  
Moisture Susceptibility ◽  
Dry Conditions ◽  
Control Samples

In this study, the effect of using Polypropylene (PP) as an antistripping additive of asphalt mixtures is investigated. Here, the moisture susceptibility of asphalt mixtures is evaluated by determining the micro-mechanisms using the surface free energy (SFE) concept. The adhesion bond between the aggregate and asphalt binder and the cohesion strength of the asphalt binder are considered as the main factors that affect moisture damage of asphalt mixtures. Test results indicate that the use of PP improves the resistance of asphalt mixtures in both wet and dry conditions. Also, the results of the SFE tests showed that the modifying asphalt binder with PP increases free energy of adhesion that will improve adhesion resistance between asphalt binder-aggregates. The amount of debonding energy in the samples which are modified with PP is lower than the control samples. This shows that by modifying asphalt binders, the tendency of asphalt binder-aggregate stripping can be reduced. The results show the total SFE of the asphalt binders of the modified samples have more free energy rather than the control samples. This phenomenon shows that failure in the asphalt binder film and cohesion failure will be happened more rarely.

scholarly journals Effect of Nanoclay Particles on the Performance of High-Density Polyethylene-Modified Asphalt Concrete Mixture

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 434
Author(s):  
Ghada S. Moussa ◽  
Ashraf Abdel-Raheem ◽  
Talaat Abdel-Wahed
Keyword(s):  
Asphalt Concrete ◽  
High Density Polyethylene ◽  
Storage Stability ◽  
Chemical Change ◽  
Asphalt Binder ◽  
Moisture Damage ◽  
High Density ◽  
Damage Resistance ◽  
Negative Impacts ◽  
Roadway Construction

Utilizing polymers for asphalt concrete (AC) mixture modification has many drawbacks that hinder its wide implementations for roadway construction. Recently, research on employing complementary materials, such as nanomaterials, to balance negative impacts of polymers while enhancing the AC mixture’s performance has received great attention. This study aimed to investigate the effect of incorporating nanoclay (NC) particles on the performance of a high-density polyethylene (HDPE)-modified AC mixture. A 60/70 asphalt binder was first modified with HDPE, and then NC particles were gradually added at a concentration of 1–4% by weight of the asphalt binder. The binders’ physical characteristics, storage stability, and chemical change were scrutinized. AC mixture performance, including pseudo-stiffness, moisture damage resistance, stripping susceptibility, and rutting tendency, was investigated. A statistical analysis on the experimental results was conducted using Kruskal–Wallis and Dunn tests. Test results showed that employing NC/HDPE significantly increased penetration index and thereby enhanced binder temperature sensitivity. Moreover, it prevented oxidation action and separation and, therefore, enhanced binder storage stability. Furthermore, incorporating NC amplified pseudo-stiffness and significantly improved resistance against moisture damage and stripping of HDPE-modified mixtures. Moreover, it improved both elastic (recoverable) and plastic (unrecoverable) deformations of mixtures. The most satisfactory results were attained when incorporating 3% of NC.

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