scholarly journals Evaluation of Rheological Behavior, Resistance to Permanent Deformation, and Resistance to Fatigue of Asphalt Mixtures Modified with Nanoclay and SBS Polymer

2019 ◽  
Vol 9 (13) ◽  
pp. 2697
Author(s):  
Gabriela Ceccon Carlesso ◽  
Glicério Trichês ◽  
João Victor Staub de Melo ◽  
Matheus Felipe Marcon ◽  
Liseane Padilha Thives ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Rheological Behavior ◽  
Complex Modulus ◽  
Permanent Deformation ◽  
Asphalt Binder ◽  
Fatigue Cracking ◽  
Fatigue Tests ◽  
Asphalt Mixtures ◽  
The Road ◽  
Styrene Butadiene

Fatigue cracking and rutting are among the main distresses identified in flexible pavements. To reduce these problems and other distresses, modified asphalt mixtures have been designed and studied. In this regard, this paper presents the results of a study on rheological behavior and resistance to permanent deformation and to fatigue of four different asphalt mixtures: (1) with conventional asphalt binder (CAP 50/70); (2) with binder modified by nanoclay (3% NC); (3) with binder modified by styrene–butadiene–styrene polymer (SBS 60/85); and (4) with binder modified by nanoclay and SBS (3% NC + 2% SBS). For this analysis, the mixtures were evaluated based on complex modulus, permanent deformation tests, and fatigue tests (4PB, in the four-point bending apparatus), with the subsequent application of numerical simulations. The results obtained show a better rheological behavior related to greater resistance to permanent deformation for the mixture 3% NC + 2% SBS, which could represent an alternative for roads where a high resistance to rutting is required. Otherwise, on fatigue tests, higher resistance was observed for the SBS 60/85 mixture, followed by the 3% NC + 2% SBS mixture. Nevertheless, based on the results of the numerical simulations and considering the possibility of cost reduction for the use of the 3% NC + 2% SBS mixture, it is concluded that this modified material has potential to provide improvements to the road sector around the world, especially in Brazil.

scholarly journals Deformation Parameters and Fatigue of the Recycled Asphalt Mixtures

2015 ◽  
Vol 11 (2) ◽  
pp. 115-120
Author(s):  
Juraj Šrámek
Keyword(s):  
Complex Modulus ◽  
Permanent Deformation ◽  
Asphalt Mixtures ◽  
Test Method ◽  
Traffic Load ◽  
Bending Test ◽  
Recycled Asphalt ◽  
The Road ◽  
Dynamic Methods ◽  
Deformation Complex

Abstract The deformational properties of asphalt mixtures measured by dynamic methods and fatigue allow a design the road to suit the expected traffic load. Quality of mixtures is also expressed by the resistance to permanent deformation. Complex modulus of stiffness and fatigue can reliably characterize the proposed mixture of asphalt pavement. The complex modulus (E*) measurement of asphalt mixtures are carried out in laboratory of Department of Construction Management at University of Žilina by two-point bending test method on trapezoid-shaped samples. Today, the fatigue is verified on trapezoid-shaped samples and is assessed by proportional strain at 1 million cycles (ε6). The test equipment and software is used to evaluate fatigue and deformation characteristics.

scholarly journals Low-Temperature Performance of Polymer-Modified Binders in Stone Mastic Asphalts

2021 ◽  
Vol 6 (4) ◽  
pp. 58
Author(s):  
Ana Dias ◽  
Hugo Silva ◽  
Carlos Palha ◽  
Joel Oliveira
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
Elastic Recovery ◽  
Permanent Deformation ◽  
Asphalt Binder ◽  
Fatigue Cracking ◽  
Thermal Cracking ◽  
Mechanical Tests ◽  
Asphalt Mixtures ◽  
Modified Binders

When temperatures drop to significantly low levels, road pavements are subjected to thermally-induced stresses, resulting in the appearance of thermal cracking, among other distresses. In these situations, polymers can be used as asphalt binder modifiers to improve certain asphalt binder properties, such as elastic recovery, cohesion, and ductility. Polymers also minimize some of the problems of asphalt mixtures, such as thermal and fatigue cracking and permanent deformation. This work’s objective was to study the behavior of asphalt mixtures at low temperatures, mainly when using modified binders. Thus, three binders were selected and tested: a standard 50/70 penetration grade bitumen and two polymer-modified binders (PMB), obtained by adding, respectively, 2.5% and 5.0% of styrene–butadiene–styrene (SBS) in the 50/70 pen grade bitumen. Then, the PMBs were incorporated into stone mastic asphalt mixtures (namely SMA 11), which were subjected to low-temperature mechanical tests based on the most recent European Standards. The asphalt binders and mixtures evaluated in this work were tested for thermal cracking resistance, creep, elastic recovery, cohesive strength, and ductility strength. Overall, it is concluded that the studied asphalt mixtures with PMB, with just 2.5% SBS, performed adequately at low temperatures down to −20 °C.

scholarly journals Performance Evaluation of WMA Containing Re-Refined Acidic Sludge and Amorphous Poly Alpha Olefin (APAO)

2021 ◽  
Vol 13 (6) ◽  
pp. 3315
Author(s):  
Mansour Fakhri ◽  
Danial Arzjani ◽  
Pooyan Ayar ◽  
Maede Mottaghi ◽  
Nima Arzjani
Keyword(s):  
Resilient Modulus ◽  
Permanent Deformation ◽  
Road Construction ◽  
Moisture Damage ◽  
Asphalt Mixtures ◽  
Modified Bitumen ◽  
Alternative Source ◽  
The Road ◽  
Marshall Test ◽  
Alpha Olefin

The use of waste materials has been increasingly conceived as a sustainable alternative to conventional materials in the road construction industry, as concerns have arisen from the uncontrolled exploitation of natural resources in recent years. Re-refined acidic sludge (RAS) obtained from a waste material—acidic sludge—is an alternative source for bitumen. This study’s primary purpose is to evaluate the resistance of warm mix asphalt (WMA) mixtures containing RAS and a polymeric additive against moisture damage and rutting. The modified bitumen studied in this research is a mixture of virgin bitumen 60/70, RAS (10, 20, and 30%), and amorphous poly alpha olefin (APAO) polymer. To this end, Marshall test, moisture susceptibility tests (i.e., tensile strength ratio (TSR), residual Marshall, and Texas boiling water), resilient modulus, and rutting assessment tests (i.e., dynamic creep, Marshall quotient, and Kim) were carried out. The results showed superior values for modified mixtures compared to the control mix considering the Marshall test. Moreover, the probability of a reduction in mixes’ moisture damage was proved by moisture sensitivity tests. The results showed that modified mixtures could improve asphalt mixtures’ permanent deformation resistance and its resilience modulus. Asphalt mixtures containing 20% RAS (substitute for bitumen) showed a better performance in all the experiments among the samples tested.

Use of Superpave Technology for Design and Construction of Rubberized Asphalt Mixtures

1997 ◽  
Vol 1583 (1) ◽  
pp. 71-81 ◽  
Author(s):  
H. Barry Takallou ◽  
Hussain U. Bahia ◽  
Dario Perdomo ◽  
Robert Schwartz
Keyword(s):  
Fatigue Behavior ◽  
Permanent Deformation ◽  
Performance Testing ◽  
Fatigue Cracking ◽  
Asphalt Mixtures ◽  
Mix Design ◽  
Asphalt Rubber ◽  
Constant Height ◽  
Overlay Design ◽  
Gyratory Compaction

The effect of different mixing times and mixing temperatures on the performance of asphalt-rubber binder was evaluated. Four different types of asphalt-rubber binders and neat asphalt were characterized using the Strategic Highway Research Program (SHRP) binder method tests. Subsequently, mix designs were carried out using both the SHRP Levels I and II mix design procedures, as well as the traditional Marshall mix design scheme. Additionally, performance testing was carried out on the mixtures using the Superpave repetitive simple shear test at constant height (RSST-CH) to evaluate the resistance to permanent deformation (rutting) of the rubberized asphalt mixtures. Also, six rectangular beams were subjected to repeated bending in the fatigue tester at different microstrain levels to establish rubberized asphalt mixtures’ resistance to fatigue cracking under repeated loadings. The results indicate that the Superpave mix design produced asphalt-rubber contents that are significantly higher than values used successfully in the field. Marshall-used gyratory compaction could not produce the same densification trends. Superpave mixture analysis testing (Level II) was used successfully for rubberized asphalt mixtures. Results clearly indicated that the mixture selected exhibited acceptable rutting and fatigue behavior for typical new construction and for overlay design. Few problems were encountered in running the Superpave models. The results of the RSST-CH indicate that rubber-modified asphalt concrete meets the criteria for a maximum rut depth of 0.5 in.; and more consistent results were measured for fatigue performance analysis using the repeated four-point bending beam testing (Superpave optional torture testing). The cycles to failure were approximately 26,000 at 600 microstrain.

Damage and Thixotropy in Asphalt Mixture and Binder Fatigue Tests

2012 ◽  
Vol 2293 (1) ◽  
pp. 8-17 ◽  
Author(s):  
Félix Pérez-Jiménez ◽  
Ramon Botella ◽  
Rodrigo Miró
Keyword(s):  
Cyclic Loading ◽  
Strain Amplitude ◽  
Fatigue Testing ◽  
Complex Modulus ◽  
Asphalt Mixture ◽  
Viscoelastic Behavior ◽  
Fatigue Cracking ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Irreversible Damage

Fatigue cracking is considered one of the main damage mechanisms in asphalt pavement design. Design methods use fatigue laws obtained by laboratory testing of the materials involved. Typically, these tests consist of subjecting the asphalt mixture to cyclic loading until failure occurs. However, failure is associated not with specimen fracture (which is unusual), but with a slight decrease in the mechanical properties of the material, usually in the complex modulus. As a consequence, it is important to differentiate between real damage to the material and changes in its viscoelastic behavior and thixotropy. It is also crucial to account for the healing that occurs in asphalt material after rest periods. The above considerations are important in the fatigue testing of asphalt binders because these materials show pronounced viscoelastic behavior and thixotropy, especially when subjected to cyclic loading. This paper demonstrates that in many cases what is taken for fatigue failure during testing (i.e., a decrease in the complex modulus below half of its initial value) is actually thixotropy. Thus, the complex modulus can be recovered by reducing the loading or, as in this study, the strain applied. In contrast, asphalt mixtures experience irreversible damage, and depending on the asphalt binder, the thixotropic effects are more or less pronounced. This paper analyzes the failure criteria currently used in the fatigue testing of asphalt mixtures and binders and evaluates the parameters chosen, namely, complex modulus (G*) and phase angle (δ) to characterize asphalt binders (G*sin δ). A cyclic uniaxial tension–compression test under strain-controlled conditions was performed. Three test modalities were used: time sweeps (constant strain amplitude until total failure), increasing strain sweeps (increase in strain amplitude every 5,000 cycles), and up-and-down strain sweeps (alternating increases and decreases in strain amplitude).

Laboratory Comparison of Permanent Deformation and Fatigue Behavior of Neat, Polymer, and Rubber-Asphalt Binders

2019 ◽  
Vol 2673 (4) ◽  
pp. 524-532
Author(s):  
Felipe F. Camargo ◽  
Kamilla Vasconcelos ◽  
Liedi L. Bernucci
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Fatigue Behavior ◽  
Permanent Deformation ◽  
Asphalt Binder ◽  
Fatigue Cracking ◽  
Fatigue Life Prediction ◽  
Polymer Modification ◽  
Neat Polymer ◽  
Percentage Recovery

Fatigue cracking and rutting are among the major types of distresses to be considered in flexible pavement design. In this context, the choice of the asphalt binder plays a major role in both the fatigue behavior and permanent deformation resistance of the asphalt mixture. This study was conducted to assess the permanent deformation and fatigue behavior of a field-blended rubber-asphalt (CRMA) and compare the results with typical binders used in Brazil. The neat binder used for modification was also employed as a control and as a base for polymer modification (SBSA). The binders were evaluated using the multiple stress creep and recovery (MSCR) for permanent deformation behavior, and the time sweep (TST) and linear amplitude sweep (LAS) tests for fatigue behavior. Modification of the neat binder resulted in an increase in percentage recovery in the MSCR, whereas the percentage recovery for CRMA was the highest among the three binders at any given temperature. The non-recoverable creep compliance for the CRMA was lower than that exhibited by the neat and SBSA binders for both stress levels for the range of temperatures tested. Binder modification resulted in an improved fatigue behavior compared with the neat binder according to the TST and LAS, whereas rubber modification resulted in the best fatigue behavior. Fatigue life prediction by TST was consistently higher than fatigue life prediction in the LAS test, probably because different criteria were used for determining failure in each test (ranking of the binders remained constant regardless of the criteria used).

Superpave Models: Predicting Performance during Design and Construction

1996 ◽  
Vol 1545 (1) ◽  
pp. 105-112
Author(s):  
Gerald A. Huber ◽  
Xishun Zhang ◽  
Robin Fontaine
Keyword(s):  
Prediction Models ◽  
Permanent Deformation ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Engineering Properties ◽  
Design System ◽  
Widespread Application ◽  
Premature Failure ◽  
The Impact

The Strategic Highway Research Program (SHRP) spent $50 million researching asphalt binders and asphalt mixtures and provided three main products: an asphalt binder specification, an asphalt mixture specification, and Superpave, an asphalt mixture design system that encompasses both the binder and mixture specification. SHRP researchers have provided tools that promise more robust asphalt mixtures with reduced risk of premature failure. Implementation of the specifications and mix design system will require overcoming several obstacles. Superpave must be demonstrated to be practical and easy to use. The impact of Superpave aggregate requirements on aggregate availability must be determined. The Superpave gyratory compaction procedure has been uniquely defined and then calibrated to traffic volume. The reasonableness of this approach must be tested in widespread application. Perhaps the largest implementation hurdle exists in the performance models. Expensive test equipment is necessary to do the performance-based tests. The performance predictions must be established as reasonable to justify the cost. A highway reconstruction project containing three Superpave Level 1 mix designs is documented including quality control done with the Superpave gyratory compactor. Superpave Level 2 performance-based tests were carried out to predict permanent deformation of the design and the mixture as constructed. The performance-based engineering properties obtained from the tests are evaluated, and the reasonableness of the performance prediction models is discussed.

scholarly journals Kajian Penambahan RejIRE pada Aspal Modifikasi Crumb Rubber serta Kinerjanya pada Campuran Beraspal Panas

2019 ◽  
Vol 24 (2) ◽  
pp. 148
Author(s):  
Sri Mulyani ◽  
Nono Nono ◽  
Nyoman Suaryana
Keyword(s):  
Heavy Traffic ◽  
Permanent Deformation ◽  
Crumb Rubber ◽  
High Viscosity ◽  
Asphalt Mixtures ◽  
Modified Asphalt ◽  
Low Viscosity ◽  
Styrene Butadiene ◽  
Sbs Modified Asphalt ◽  
Rubber Modification

Asphalt polymer has superior characteristics than conventional asphalt. Styrene Butadiene Styrene (SBS) is a polymer that has proven its performance in heavy traffic, but it must be imported and expensive. Crumb rubber have high potential to be used as an asphalt modifier. Asphalt modified crumb rubber has high viscosity and is not homogeneous, so that the utilization cannot be delayed. This reduces workability in the field. This study aims to obtain asphalt modified crumb rubber which is easier to use by adding materials that do not affect its performance. RejIRE is a low viscosity additive to restore the properties of bitumen on crumb rubber modified. Experiments were carried out by adding variations in RejIRE levels to crumb rubber modified asphalt to determine its characteristics. Continued investigation of the performance of hot paved mixtures for wearing courses compared to asphalt mixtures with Pen 60/70 asphalt and SBS modified asphalt mixtures. The result is the addition of 0.75% RejIRE on asphalt crumb rubber modification have high workability. Overall the performance of the mix with SBS modified asphalt is better, but the mixture of hot paved with modified asphalt crumb rubber has a resistance to permanent deformation superior to the other paved mixtures.

Performance of Asphalt Rejuvenators in Hot-Mix Asphalt Containing Recycled Asphalt Shingles

2017 ◽  
Vol 2633 (1) ◽  
pp. 108-116 ◽  
Author(s):  
Max A. Aguirre ◽  
Marwa M. Hassan ◽  
Sharareh Shirzad ◽  
Louay N. Mohammad ◽  
Samuel B. Cooper
Keyword(s):  
Hot Mix Asphalt ◽  
Permanent Deformation ◽  
Fatigue Cracking ◽  
Strain Energy Release ◽  
Asphalt Mixtures ◽  
Bending Test ◽  
Test Results ◽  
Recycled Asphalt ◽  
Recycled Asphalt Shingles ◽  
Asphalt Shingles

The use of recycled asphalt shingles (RAS) in asphalt paving construction represents a sustainable approach to reduce virgin material consumption and negative environmental effects, as well as the cost of asphalt pavement. However, many challenges are yet to be addressed about the use of RAS in paving applications. This study evaluated the effect of the incorporation of postconsumer waste shingles and rejuvenators on the performance of hot-mix asphalt. Four asphalt rejuvenators—one bio-oil and three synthetic oils—were evaluated. A set of laboratory tests was conducted to characterize the performance of asphalt mixtures against permanent deformation and fatigue cracking. The addition of 5% RAS showed an improvement in permanent deformation when compared with a conventional mixture with no RAS. Yet the addition of asphalt rejuvenator products slightly decreased the performance against permanent deformation. On the basis of Hamburg wheel-tracking device test results, the addition of RAS did not adversely affect moisture resistance. Yet semicircular bending test results showed that the asphalt mixtures that contained asphalt rejuvenators had a lower critical strain energy release rate than the minimum threshold value (0.5 kJ/m2), which indicated a greater susceptibility to intermediate-temperature cracking.

Sign in / Sign up

Export Citation Format

Share Document