Effect of Hydrated Lime on Long-Term Oxidative Aging Characteristics of Asphalt

2002 ◽  
Vol 1810 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Shin-Che Huang ◽  
J. Claine Petersen ◽  
Raymond Robertson ◽  
Jan F. Branthaver
Keyword(s):  
Phase Angle ◽  
Fatigue Cracking ◽  
Hydrated Lime ◽  
Age Hardening ◽  
Asphalt Binders ◽  
Asphalt Pavements ◽  
Initial Stiffness ◽  
Oxidative Aging ◽  
Useful Lifetime

An experiment involving neat asphalts AAD-1, ABD, and their mixtures with two different grades of hydrated lime was conducted to investigate the effect of lime on the long-term aging characteristics of asphalt binders. Rheological properties of unaged and aged asphalt-lime mixtures were measured with a dynamic shear rheometer at 25°C (77°F) and 60°C (140°F). The addition of hydrated lime to one asphalt (AAD-1) effectively reduced oxidative age hardening. In addition, the phase angle reached the same value as aging time reached after approximately 800 h at 60°C in the pressure-aging vessel for AAD-1 and its mixtures with lime. After 800 h of aging, the phase angle was greater for the limetreated asphalt than for the untreated asphalt, and it continued to decrease at a slower rate. This result indicates that the addition of lime to this asphalt increases the initial stiffness of the binder, but, more importantly, it preserves elasticity during long-term oxidative aging. Thus, for this asphalt, at a level of oxidation typical of pavements, limetreated and untreated asphalts arrived at the same viscosity with time, but the lime-treated asphalt had better viscous flow properties than the untreated asphalt. It could then be predicted that the aged, lime-treated asphalt would be more resistant to fatigue cracking. The other asphalt tested (ABD) did not exhibit substantial effects of lime on the rate of oxidative age hardening. This highly compatible, low-asphaltene asphalt is not typical of most paving asphalts. Because hydrated lime has been shown to reduce oxidative age hardening both in the laboratory and during the first few years in the pavement, adding hydrated lime should extend the useful lifetime of most asphalt pavements.

The Utilization of Rice Husks Powder as an Antioxidant in Asphalt Binder

2014 ◽  
Vol 567 ◽  
pp. 539-544 ◽  
Author(s):  
Mohammed Hadi Nahi ◽  
Ibrahim B. Kamaruddin ◽  
Napiah Madzlan
Keyword(s):  
Thermal Stresses ◽  
Asphalt Binder ◽  
Fine Powder ◽  
Age Hardening ◽  
Asphalt Pavements ◽  
Rice Husks ◽  
Antioxidant Additive ◽  
Oxidative Aging ◽  
Point Test

Aging is one of the main contributors for asphalt failure. Oxidation aging is the main cause of long-term deterioration in asphalt pavements as a pavement ages, oxidation stiffens a pavement, making it more susceptible to failure from load and thermal stresses. Slowing a pavement’s oxidative aging would maintain its elastic properties and delay aging problems. There is no performance enhancer in widespread use, acting as an antioxidant that slows the oxidative aging of asphalt binder. The main objective of this research is to investigate the feasibility of using biomass powder derived from rice husks as an antioxidant additive to control the asphalt age hardening. The waste of rice husks was dried at 40°C for 9–11 days. The dried materials was grounded, and sieved to get fine powder. To evaluate the performance of the antioxidant, samples have to be aged according to SUPERPAVE standards (RTFOT and PAV) and physical, chemical, and rheological properties have to be analyzed. The preliminary results of penetration test softening point test shows that adding 4% of rice husks’ powder to 80/100 binder didn’t change the grade of the binder.

Evaluation of Age-Hardening on Long-Term Aged Asphalt Binders

2021 ◽  
Vol 304 ◽  
pp. 124687
Author(s):  
Yanlong Liang ◽  
John T. Harvey ◽  
David Jones ◽  
Rongzong Wu
Keyword(s):  
Age Hardening ◽  
Asphalt Binders ◽  
Aged Asphalt

Verification and Improvement of the Rate of Asphalt Aging Simulated by AASHTO PP1–98 Protocol

2005 ◽  
Vol 1901 (1) ◽  
pp. 24-32
Author(s):  
Suresh Raghavendra ◽  
Claudia E. Zapata ◽  
M. Waseem Mirza ◽  
William N. Houston ◽  
Matthew W. Witczak
Keyword(s):  
The United States ◽  
Age Hardening ◽  
Asphalt Binders ◽  
Pavement Performance ◽  
Ongoing Research ◽  
Aging Conditions ◽  
Original Laboratory ◽  
Laboratory Procedures ◽  
Pavement Aging

It is well documented that environmental effects play a significant role in characterizing material properties, which in turn affect pavement performance. Studies under the Strategic Highway Research Program (SHRP) were carried out on the age-hardening characteristics of asphalt binders and mixes. As a result, laboratory procedures to simulate the field hardening of asphalt binders and mixes, AASHTO Provisional Protocols PP1–98 and PP2–99, were developed. The approaches followed in these procedures are of great value for the ongoing research on pavement aging; however, due to limited resources and time constraints under the SHRP program, these provisional procedures have certain limitations. A research study, NCHRP Project 9–23, was initiated to overcome these limitations and enhance the predictive capabilities of these protocols. The current research paper is a part of NCHRP 9–23, which deals with the PP1–98 protocol. Binders and field cores were obtained from long-term pavement performance and other sites across the United States. Original, laboratory-aged, and field-aged binders were characterized through dynamic shear rheometer testing. The existing protocol was verified; on the basis of the findings, the protocol was improved to include the effect of field aging conditions and mix properties. The developed model was calibrated and validated with field data. Parametric analysis was performed on the final model to ascertain the practicality of the output. On the basis of those findings, a recommended provisional protocol was developed. The recommendations apply only for conventional, nonmodified binders.

scholarly journals Chemical and Rheological Evaluation of Aged Lignin-Modified Bitumen

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4176 ◽  
Author(s):  
Yi Zhang ◽  
Xueyan Liu ◽  
Panos Apostolidis ◽  
Wolfgang Gard ◽  
Martin van de Ven ◽  
...  
Keyword(s):  
Environmental Benefits ◽  
Asphalt Pavements ◽  
Environmental Scanning ◽  
Physical Interaction ◽  
Test Results ◽  
Modified Bitumen ◽  
Oxidative Aging ◽  
Anti Oxidant ◽  
Rheological Effect

As bitumen oxidizes, material stiffening and embrittlement occur, and bitumen eventually cracks. The use of anti-oxidants, such as lignin, could be used to delay oxidative aging and to extend the lifetime of asphalt pavements. In this study, the chemical and rheological effect of lignin on bitumen was evaluated by using a single dosage organsolv lignin (10 wt.% dosage). A pressure aging vessel (PAV) was used to simulate the long-term aging process after performing the standard short-term aging procedure, and the lignin-modified bituminous binders were characterized by an environmental scanning electron microscope (ESEM), Fourier-transform infrared (FTIR) spectroscopy, and a dynamic shear rheometer (DSR). From the ESEM results, the uniform microstructure was observed, indicating that the addition of lignin did not affect the worm structure of bitumen. Based on the FTIR test results, lignin-modified bitumen showed that a lower number of carbonyl and sulfoxide compounds were generated after aging than for neat bitumen. Based on the linear amplitude sweep (LAS) results, the addition of lignin slightly reduced the fatigue life of bitumen. From the frequency sweep results, it showed that lignin in bitumen acts as a modifier since the physical interaction between lignin and bitumen predominantly affects the material rheology. Overall, lignin could be a promising anti-oxidant due to its economic and environmental benefits.

Evaluation of Carbon Nanotubes Asphalt Modification Using the Superpave Criteria

2021 ◽  
Vol 902 ◽  
pp. 135-143
Author(s):  
Mohammad Ali Khasawneh ◽  
Khalid Ghuzlan ◽  
Nada Bani Melhem
Keyword(s):  
Carbon Nanotubes ◽  
Low Temperature ◽  
Rheological Properties ◽  
Asphalt Binder ◽  
Fatigue Cracking ◽  
Asphalt Binders ◽  
Asphalt Pavements ◽  
Low Temperature Cracking ◽  
Asphalt Modification ◽  
Rotational Viscosity

Rutting, fatigue cracking and low temperature cracking are the most important distresses in asphalt pavements as a result of changes in rheological properties of asphalt binder. Many types of modifiers were used to enhance asphalt behavior at both low and high temperatures. In this study, carbon nanotubes (CNT) were used as one of many nanomaterials that take a large attention in the latest research related to asphalt modification against different types of distresses. Effect of CNT on rheological properties of asphalt binder was investigated by testing unmodified and CNT modified asphalt binders using two of Superpave devices: Dynamic Shear Rheometer (DSR) and Bending Beam Rheometer (BBR). Penetration, softening point, flash point and rotational viscosity (RV) tests were carried out as well. CNT was added in 0.1%, 0.5% and 1% by weight of asphalt binder. It was found that adding CNT in 0.5% and 1% increase stiffness of asphalt and consequently asphalt pavement rutting resistance. On the other hand, this increase in stiffness affected pavement behavior adversely which is not desirable for fatigue and low temperature cracking. However, Superpave specifications were still satisfied and asphalt binder’s relaxation properties were improved upon CNT modification. It was eventually found that 0.5% of CNT is the optimum percentage for the best performance.

scholarly journals KENTRACK 4.0: A Railway Trackbed Structural Design Program

2014 ◽  
Author(s):  
Jerry G. Rose ◽  
Shushu Liu ◽  
Reginald R. Souleyrette
Keyword(s):  
Structural Design ◽  
Fatigue Cracking ◽  
Asphalt Binders ◽  
Material Parameters ◽  
Compressive Stresses ◽  
Design Program ◽  
Subgrade Modulus ◽  
Text Formation ◽  
Windows Xp

The KENTRACK program is a finite element based railway trackbed structural design program that can be utilized to analyze trackbeds having various combinations of all-granular and asphalt-bound layered support. It is applicable for calculating compressive stresses at the top of subgrade, indicative of potential long-term trackbed settlement failure. Furthermore, for trackbeds containing an asphalt layer, it is applicable for calculating tensile strains at the bottom of the asphalt layer, indicative of potential fatigue cracking. The program was recently expanded to include both English and international units. A procedure has been incorporated to provide a path to save results in a text formation in post-Windows XP operating systems. More importantly, properties of performance graded (PG) asphalt binders and the Witczak E* predictive model have been incorporated in the 4.0 Version of the program. Component layers of typical trackbed support systems are analyzed while evaluating the significance of layer thicknesses and material properties on design and predicted performance. The effect of various material parameters and loading magnitudes on trackbed design and evaluation, as determined and predicted by the computer program, are presented. Variances in subgrade modulus and axle loads and the incorporation of a layer of asphalt within the track structure have significant effects on subgrade vertical compressive stresses and predicted trackbed service lives. The parameter assessments are presented and evaluated using sensitivity analysis.

scholarly journals Study of Asphalt-Concrete Pavement Fatigue Modeling

2021 ◽  
Vol 16 (1) ◽  
pp. 24-36
Author(s):  
Peteris Skels ◽  
Viktors Haritonovs ◽  
Pavel Akishin ◽  
Andris Freimanis
Keyword(s):  
Fatigue Cracks ◽  
Fatigue Cracking ◽  
Element Model ◽  
Fatigue Behaviour ◽  
Asphalt Pavements ◽  
Fatigue Properties ◽  
Surface Loading ◽  
Asphalt Concrete Pavement ◽  
Cyclic Surface

Deterioration of asphalt pavements due to fatigue cracking is one of the most common highway pavement failure types. If the fatigue cracks are allowed to develop and grow, the driving comfort and safety, i.e., serviceability of the pavement, decreases. Pavement fatigue behaviour is not a straightforward mechanism and involves many factors and effects, thus computational methods are developed in order to help understand how the pavement works. This paper explores the accuracy and applicability of a less computational resource demanding procedure that uses transient material mechanical behaviour to model the long-term behaviour of a pavement structure. First, the mechanical and fatigue properties of asphalt were determined at the laboratory. Then a four-layer finite-element model was created using Ansys software. Two different models – with and without infinity elements – and two different fatigue simulation procedures – full and simplified – were considered. Material parameters were obtained by the laboratory tests and material properties degraded over time. Cyclic surface loading was applied to simulate the passing of a truck – 6 million fatigue cycles were simulated.

Performance of Flexible Pavement Rehabilitation Treatments in the Long-Term Pavement Performance SPS-5 Experiment

2003 ◽  
Vol 1823 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Kathleen T. Hall ◽  
Carlos E. Correa ◽  
Amy L. Simpson
Keyword(s):  
Asphalt Pavement ◽  
Fatigue Cracking ◽  
Flexible Pavement ◽  
Asphalt Pavements ◽  
Pavement Performance ◽  
Recycled Asphalt ◽  
Pavement Rehabilitation ◽  
Pretreatment Condition ◽  
Asphalt Overlay

The results of a study conducted to assess the relative performance of different flexible pavement rehabilitation treatments, including the influence of pretreatment condition and other factors, are presented. The data used in the study were drawn from the Long-Term Pavement Performance Studies' Specific Pavement Study (SPS) SPS-5 and General Pavement Study (GPS) GPS-6B experiments. The rehabilitation treatments used in the SPS-5 experiment are 2- and 5-in. overlays with virgin or recycled asphalt concrete mixes with or without preoverlay milling. Overlay thickness and preoverlay roughness levels were the two factors that most influenced the performance of the asphalt overlays of asphalt pavements in the SPS-5 experiment with respect to roughness, rutting, and fatigue cracking. Over the long term, the 5-in. overlays outperformed the 2-in. overlays with respect to roughness, rutting, and fatigue cracking. Overlay mix type (virgin versus recycled) and preoverlay preparation (with or without milling) had slight and inconsistent effects. The average initial postoverlay international roughness index of an asphalt overlay of an asphalt pavement was found to be 0.98 m/km. The data show a slight but statistically significant tendency for asphalt pavements overlaid when they were rougher to have more initial roughness after overlay than asphalt pavements overlaid when they were smoother. The data show that, on average, about 6 mm of rutting develops in the first year or so after placement of an asphalt overlay of an asphalt pavement. This is presumably due to compaction of the mix by traffic and appears to be independent of the overlay thickness, mix type, preoverlay preparation, and preoverlay rutting level.

High, intermediate and low temperature performance appraisal of elastomeric and plastomeric asphalt binders and mixes

2021 ◽  
pp. 009524432110386
Author(s):  
Aboelkasim Diab ◽  
Jorge Pais ◽  
Siyu Chen ◽  
Ankit Gupta ◽  
Xuelian Li ◽  
...  
Keyword(s):  
Low Temperature ◽  
Performance Appraisal ◽  
Permanent Deformation ◽  
Fatigue Cracking ◽  
Intermediate Temperature ◽  
Age Hardening ◽  
Asphalt Binders ◽  
Temperature Performance ◽  
Low Temperature Cracking ◽  
The Impact

This paper is oriented to appraise high, intermediate, and low temperature related performance of elastomeric and plastomeric binders and mixtures in order to evaluate their characteristics at various levels of environmental and loading conditions. Artificial oxidative hardening of asphalt binders and mixes was performed in the laboratory using short- and long-term aging protocols.At the binder level, the elastomers (styrene-butadiene-styrene (SBS) and rubber) and plastomer (ethylene-vinyl acetate (EVA)) materials improved high and intermediate temperature performance indices (G*/sin(δ) and G*.sin(δ), respectively). Interestingly, the aged SBS/bitumen blend had improved low-temperature cracking resistance compared to unaged counterpart. With the progress of oxidative hardening, the plastomer based binder did not show obvious change in the low-temperature cracking susceptibility compared to elastomer-modified binder. Seemingly, in the case of plastomer/bitumen blend, the propensity to low-temperature cracking is to a great extent controlled by the corresponding base bitumen. The plastomer based mixture had improved permanent deformation performance, whereas the elastomers afforded a tangible amelioration for the vulnerability to load and non-load associated cracking. The SBS based mixture showed highest low-temperature fracture energy compared to the EVA based mixture. Despite the determinantal effect of age-hardening to low and intermediate temperature-related cracking of mixes, the results confirmed that the elastomeric materials can retard the impact of aging level on the low temperature and fatigue cracking. Comparision of results was justified by the statistical analysis in order to determine the significance of bituminous material parameters on the measured properties.

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