Fatigue Resistance of Bituminous Mixtures and Mortars Containing High Reclaimed Asphalt Content

With the increased use of reclaimed asphalt (RA), the ability of bituminous materials to resist fatigue cracking may face a decline mainly due to the aged reclaimed asphalt binder (RAB), especially when RA is used at higher rates and not sufficiently treated. In this study, the bulk scale (asphalt) and its subscale (mortar) were employed to evaluate the effect on fatigue resistance when a RAB is added, by considering three replacement rates: 0%, 40%, and 70% RAB. The fatigue testing of asphalt mixtures was carried out using a four-point bending (4PB) setup, while the mortars were tested using a new column-like geometry utilising a dynamic shear rheometer (DSR). The fatigue properties were further analysed using dissipated energy concepts. The aim of this study was, first, to assess whether the inclusion of a RAB can provide at least similar fatigue properties compared to an all-virgin mix, and second, to evaluate whether the proposed treatment is beneficial for the mixtures with a RAB. The asphalt tests revealed that the inclusion of a 40% RAB led to increased fatigue resistance, whereas the mortar tests showed that the inclusion of RAB has an inverse effect on fatigue life.

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Binder and Mixture Fatigue Performance of Plant-Produced Road Surface Course Asphalt Mixtures with High Contents of Reclaimed Asphalt

Sustainability ◽

10.3390/su11133752 ◽

2019 ◽

Vol 11 (13) ◽

pp. 3752 ◽

Cited By ~ 1

Author(s):

Subhy ◽

Pires ◽

Carrión ◽

Presti ◽

Airey

Keyword(s):

Asphalt Mixture ◽

Fatigue Cracking ◽

Asphalt Mixtures ◽

Road Surface ◽

Fatigue Performance ◽

Fatigue Properties ◽

Dissipated Energy ◽

Reclaimed Asphalt ◽

Tensile Fatigue ◽

Fatigue Characteristics

The aged properties of Reclaimed Asphalt (RA) binders are one of the main factors working against their utilisation in high-RA content (>30%) mixes for surface courses. Fatigue cracking is the main distress of surface courses that are manufactured with a high percentage of RA. This investigation presents results of the rheological and fatigue results of different asphalt mixtures and their recovered binders. The binders were recovered from asphalt mixtures that had been manufactured in asphalt plants using different amounts of RA with contents up to 60% with and without rejuvenators. Two different sources of RA were used, representing a moderately aged RA and an extremely aged RA. The Dynamic Shear Rheometer (DSR) was used to assess the fatigue-characteristics of the binders using time sweep tests while the fatigue characteristics of their mixtures were assessed using the Indirect Tensile Fatigue Test (ITFT). The fatigue data was analysed based on the cumulative dissipated energy approach in addition to traditional fatigue analysis. Results have shown that the ageing condition of RA significantly affects the fatigue properties of recovered binders. Binder and asphalt mixture fatigue results showed that RA contents up to 60% can produce comparable fatigue performance compared to lower percentages of RA in road surface course if the aged RA binder is sufficiently rejuvenated.

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Fatigue Resistance and Cracking Mechanism of Semi-Flexible Pavement Mixture

Materials ◽

10.3390/ma14185277 ◽

2021 ◽

Vol 14 (18) ◽

pp. 5277

Author(s):

Shiqi Wang ◽

Huanyun Zhou ◽

Xianhua Chen ◽

Minghui Gong ◽

Jinxiang Hong ◽

...

Keyword(s):

Low Temperature ◽

Fatigue Resistance ◽

Stress Ratio ◽

Asphalt Binder ◽

Asphalt Mixture ◽

Fatigue Cracking ◽

Flexible Pavement ◽

The Poor ◽

Grouting Material ◽

Cracking Mechanism

Semi-flexible pavement (SFP) is widely used in recent years because of its good rutting resistance, but it is easy to crack under traffic loads. A large number of studies are aimed at improving its crack resistance. However, the understanding of its fatigue resistance and fatigue-cracking mechanism is limited. Therefore, the semi-circular bending (SCB) fatigue test is used to evaluate the fatigue resistance of the SFP mixture. SCB fatigue tests under different temperature values and stress ratio were used to characterize the fatigue life of the SFP mixture, and its laboratory fatigue prediction model was established. The distribution of various phases of the SFP mixture in the fracture surface was analyzed by digital image processing technology, and its fatigue cracking mechanism was analyzed. The results show that the SFP mixture has better fatigue resistance under low temperature and low stress ratio, while its fatigue resistance under other environmental and load conditions is worse than that of asphalt mixture. The main reason for the poor fatigue resistance of the SFP mixture is the poor deformation capacity and low strength of grouting materials. Furthermore, the performance difference between grouting material and the asphalt binder is large, which leads to the difference of fatigue cracking mechanism of the SFP mixture under different conditions. Under the fatigue load, the weak position of the SFP mixture at a low temperature is asphalt binder and its interface with other materials, while at medium and high temperatures, the weak position of the SFP mixture is inside the grouting material. The research provides a basis for the calculation of the service life of the SFP structure, provides a reference for the improvement direction of the SFP mixture composition and internal structure.

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Tensile and Fatigue Properties of Friction Stir Processed NiAl Bronze

Materials Science Forum ◽

10.4028/www.scientific.net/msf.539-543.3751 ◽

2007 ◽

Vol 539-543 ◽

pp. 3751-3756 ◽

Cited By ~ 7

Author(s):

Christian B. Fuller ◽

Murray W. Mahoney ◽

William H. Bingel ◽

Michael Calabrese ◽

B. London

Keyword(s):

Fatigue Resistance ◽

Fatigue Testing ◽

Processing Parameters ◽

Fatigue Properties ◽

Friction Stir ◽

Refined Microstructure ◽

Property Data ◽

Rotating Bending Fatigue ◽

Rotating Bending ◽

Property Characterization

Friction stir processing (FSP) produced local microstructural refinement in cast Ni Al Bronze. The refined microstructure quality was evaluated with mechanical property characterization using monotonic tension and fatigue testing as a function of FSP raster patterns. Modifying the cast NiAl bronze with FSP resulted in a 140 - 172 % increase in yield strength, and a 40 - 57% increase in tensile strength. Changing the raster pattern from a linear to a rectangular spiral raster increased the tensile elongations by 40 - 134%. This increase in elongation was attributed to increased microstructural uniformity through the depth of the FSP raster. The ability to transfer FSP technology was demonstrated with consistent tensile property data produced by three different laboratories. Fatigue characterization (both uniaxial and rotating-bending fatigue) showed that FSP improved the cast NiAl bronze fatigue resistance. Both types of fatigue testing showed differences in fatigue resistance as a function of processing parameters.

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The Effect of Aging on the Cracking Resistance of Recycled Asphalt

Advances in Civil Engineering ◽

10.1155/2017/7240462 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Mojtaba Mohammadafzali ◽

Hesham Ali ◽

James A. Musselman ◽

Gregory A. Sholar ◽

Aidin Massahi

Keyword(s):

Asphalt Binder ◽

Asphalt Mixture ◽

Fatigue Cracking ◽

Asphalt Mixtures ◽

Asphalt Binders ◽

Reclaimed Asphalt Pavement ◽

Cracking Resistance ◽

Recycled Asphalt ◽

Reclaimed Asphalt ◽

Important Concern

Fatigue cracking is an important concern when a high percentage of Reclaimed Asphalt Pavement (RAP) is used in an asphalt mixture. The aging of the asphalt binder reduces its ductility and makes the pavement more susceptible to cracking. Rejuvenators are often added to high-RAP mixtures to enhance their performance. The aging of a rejuvenated binder is different from virgin asphalt. Therefore, the effect of aging on a recycled asphalt mixture can be different from its effect on a new one. This study evaluated the cracking resistance of 100% recycled asphalt binders and mixtures and investigated the effect of aging on this performance parameter. The cracking resistance of the binder samples was tested by a Bending Beam Rheometer. An accelerated pavement weathering system was used to age the asphalt mixtures and their cracking resistance was evaluated by the Texas Overlay Test. The results from binder and mixture tests mutually indicated that rejuvenated asphalt has a significantly better cracking resistance than virgin asphalt. Rejuvenated mixtures generally aged more rapidly, and the rate of aging was different for different rejuvenators.

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Preparation and Mechanical-Fatigue Properties of Elastic Polyurethane Concrete Composites

Materials ◽

10.3390/ma14143839 ◽

2021 ◽

Vol 14 (14) ◽

pp. 3839

Author(s):

Zhen Jia ◽

Dongzhe Jia ◽

Quansheng Sun ◽

Yanqi Wang ◽

Hongjian Ding

Keyword(s):

Fatigue Life ◽

Fatigue Resistance ◽

Building Materials ◽

Prediction Models ◽

Engineering Application ◽

Tensile Tests ◽

Fatigue Properties ◽

Dissipated Energy ◽

Fine Aggregate ◽

Rubber Particles

In order to solve issues related to bridge girders, expansion devices and road surfaces, as well as other structures that are prone to fatigue failure, a kind of fatigue-resistant elastic polyurethane concrete (EPUC) was obtained by adding waste rubber particles (40 mesh with 10% fine aggregate volume replacement rate) to conventional engineering polyurethane concrete (PUC). Based on the preparation and properties of EPUC, its constitutive relation was proposed through compression and tensile tests; then, a scanning electron microscope (SEM), an atomic force microscope (AFM) and a 3D non-contact surface profilometer were used to study the failure morphology and micromechanisms of EPUC. On this basis, four-point bending fatigue tests of EPUC were carried out at different temperature levels (−20 °C, 0 °C, 20 °C) and different strain levels (400 με~1200 με). These were used to analyze the stiffness modulus, hysteresis angle and dissipated energy of EPUC, and our results outline the fatigue life prediction models of EPUC at different temperatures. The results show that the addition of rubber particles fills the interior of EPUC with tiny elastic structures and effectively optimizes the interface bonding between aggregate and polyurethane. In addition, EPUC has good mechanical properties and excellent fatigue resistance; the fatigue life of EPUC at a room temperature of 600 με can grow by more than two million times, and it also has a longer service life and reduced disease frequency, as well as fewer maintenance requirements. This paper will provide a theoretical and design basis for the fatigue resistance design and engineering application of building materials. Meanwhile, the new EPUC material has broad application potential in terms of roads, bridges and green buildings.

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PERFORMANCE PREDICTION OF WARM MIX ASPHALT PAVEMENT CONTAINING RECLAIMED ASPHALT PAVEMENT IN RHODE ISLAND

10.23860/thesis-shrestha-neha-2019 ◽

2019 ◽

Author(s):

◽

Neha Shrestha ◽

Keyword(s):

Surface Layer ◽

Asphalt Pavement ◽

Asphalt Binder ◽

Fatigue Cracking ◽

Thermal Cracking ◽

Creep Recovery ◽

Reclaimed Asphalt Pavement ◽

Cracking Resistance ◽

Rutting Resistance ◽

Reclaimed Asphalt

The warm mixed asphalt (WMA) technology has gained a lot of interests in the recent years in academia, state agencies and industries. WMA technology allows reductions in production and compaction temperatures guaranteeing relevant environmental and cost saving benefits. The purpose of the present study was to study and evaluate the performance of a typical additive in WMA pavement with Reclaimed Asphalt Pavement (RAP) on rutting, fatigue cracking and thermal cracking resistance on RI Route 102. In the present study, the asphalt binder was tested at different dosages of additive using Dynamic Shear Rheometer (DSR), Rolling Thin Film Oven (RTFO), Pressure Aging Vessel (PAV), Multiple Stress Creep Recovery (MSCR) and Bending Beam Rheometer (BBR). From the overall test, it was found that 0.7% additive would lessen pavement damage due to rutting, fatigue cracking and thermal cracking. Based on the results of binder test, Hot Mix Asphalt (HMA) and WMA specimens containing 20 % RAP were prepared using PG 58-28 asphalt binder and Superpave Gyratory Compactor (SGC). From the volumetric analysis of both HMA and WMA specimens, it was determined that the optimum binder content (OBC) for HMA with 20% RAP was 5.3 percent and the OBC for WMA (0.7% additive with RAP was 5.6%. It was found that the required amount of neat regular asphalt binder for WMA specimen was higher than the one required by HMA. HMA and WMA Specimens with each containing 20% RAP were prepared at OBC and indirect tensile (IDT) strength test were conducted on that specimen. The test indicated that the performance of HMA mixtures was better than WMA with same amount of RAP. RI Route 102 was used as case study in this research study. Route 102 was rehabilitated through Full Depth Reclamation (FDR) in 2015. First half road of RI Route 102 was built with HMA base and surface layer and the other half was built with WMA base and surface layer using a typical additive. It was found that both sections have similar value in Pavement Serviceability Index (PSI) and in International Roughness Index (IRI) at this time. Four specimens were prepared to predict the performance of asphalt pavement using the dynamic modulus and the master curve. Two HMA specimens each were prepared with and without RAP. Similarly, other two WMA specimens were prepared with and without RAP. These four specimens were tested with the Asphalt Mixture Performance Tester (AMPT) machine and developed the master curves for each specimen. The results of the material testing were used to predict the performance of each test sections by using AASHTOWare Pavement ME Design (PavementME) software. It was found that the WMA-RAP performed better in fatigue cracking resistance but was found to perform poor in rutting resistance than HMA and HMA-RAP. This indicated that fatigue cracking was not a problem with WMA-RAP mixtures whereas rutting resistance still requires further investigation and improvement.

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Development of a Simple Fatigue Cracking Test for Asphalt Binders

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/2632-09 ◽

2017 ◽

Vol 2632 (1) ◽

pp. 79-87 ◽

Cited By ~ 4

Author(s):

Fujie Zhou ◽

Pravat Karki ◽

Soohyok Im

Keyword(s):

Fatigue Test ◽

Fatigue Resistance ◽

Asphalt Binder ◽

Fatigue Cracking ◽

Asphalt Binders ◽

Index Test ◽

Test Results ◽

Long Time ◽

Aging Conditions ◽

Binder Aging

Current Superpave® PG specification uses parameter | G*|sin(δ) to quantify asphalt binder fatigue resistance. The parameter’s effectiveness has been debated for a long time. AASHTO recently adopted the linear amplitude sweep test as a provisional standard, AASHTO TP 101-12. The authors evaluated the sensitivity of this standard to different aging conditions: unaged original binders, rolling thin-film oven-aged binders, and 20- to 80-h pressure aging vessel–aged binders. Test results showed, in many cases, longer predicted fatigue lives for more-aged binders. Thus this study developed a simple fatigue cracking test for asphalt binders. In this new test, the pure linear amplitude sweep (PLAS) test, peak shear strain was increased linearly from 0% to 30% over a course of 3,000 oscillatory cycles. A new fatigue parameter, the fatigue resistance energy index (FREI), was derived with fracture mechanics. The PLAS test and FREI parameter were sensitive to both binder aging conditions and rejuvenator type and dosage. Four laboratory mixtures were employed to evaluate the correlation between this new binder fatigue test and the two mixture cracking tests: the Texas overlay test and the Illinois flexibility index test. The results showed that the PLAS and FREI correlated well with the mixture cracking tests. Additionally, the proposed method was preliminarily verified with the FHWA accelerated loading facility test, and a fair relationship with the full-scale fatigue test data was observed. It is obvious that the PLAS and associated FREI need further validation through more field test sections.

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Fatigue Evaluation of Recycled Asphalt Mixture Based on Energy-Controlled Mode

Advances in Materials Science and Engineering ◽

10.1155/2017/3623658 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Tao Ma ◽

Kai Cui ◽

Yongli Zhao ◽

Xiaoming Huang

Keyword(s):

Fatigue Life ◽

Asphalt Mixture ◽

Asphalt Mixtures ◽

Fatigue Performance ◽

Fatigue Properties ◽

Dissipated Energy ◽

Recycled Asphalt ◽

Reclaimed Asphalt ◽

Bending Fatigue Test ◽

Fatigue Evaluation

The fatigue properties of asphalt mixtures are important inputs for mechanistic-empirical pavement design. To understand the fatigue properties of asphalt mixtures better and to predict the fatigue life of asphalt mixtures more precisely, the energy-controlled test mode was introduced. Based on the implementation theory, the laboratory practice for the energy-controlled mode was realized using a four-point-bending fatigue test with multiple-step loading. In this mode, the fatigue performance of typical AC-20 asphalt specimens with various reclaimed asphalt pavement (RAP) contents was tested and evaluated. Results show that the variation regulation of the dissipated energy and accumulative energy is compatible with the loading control principle, which proves the feasibility of the method. In addition, the fatigue life of the asphalt mixture in the energy-controlled mode was between that for the stress-controlled and strain-controlled modes. The specimen with a higher RAP content has a longer fatigue life and better fatigue performance.

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Recyclability Potential of Induction-Healable Porous Asphalt Mixtures

Sustainability ◽

10.3390/su12239962 ◽

2020 ◽

Vol 12 (23) ◽

pp. 9962

Author(s):

Pedro Lastra-González ◽

Irune Indacoechea-Vega ◽

Miguel A. Calzada-Pérez ◽

Daniel Castro-Fresno

Keyword(s):

Fatigue Resistance ◽

Mechanical Performance ◽

Asphalt Mixture ◽

Asphalt Mixtures ◽

Resistance Test ◽

Reclaimed Asphalt ◽

Porous Asphalt ◽

Bituminous Mixtures ◽

Water Sensitivity ◽

Wool Fibers

The potential recyclability of healable asphalt mixtures has been analyzed in this paper. A healable porous asphalt mixture with steel wool fibers was artificially aged in order to assess its recyclability. This mixture was used as reclaimed asphalt in a new porous asphalt mixture, whose mechanical and healing capacities were studied and compared with the behavior of the original porous asphalt mixture. The quantity of reclaimed asphalt mixture added was 40%; besides, in order to recover the properties of the aged binder, and incorporate the last advances in the recyclability of bituminous mixtures, a rejuvenator was also added (SYLVAROAD™ RP1000). The voids test, Cantabro particle loss test, water sensitivity test, stiffness test, and fatigue resistance test were performed to mechanically study the experimental mixture, while the last one (fatigue resistance test) was also used to assess its healing capacity. The results have shown that the healing capacity of the original healable porous asphalt mixture is maintained with similar mechanical performance.

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Microstructural Adjustment of the Degenerated Graphite Layer in Ductile Iron for Targeted Evaluation on the Fatigue Properties

International Journal of Metalcasting ◽

10.1007/s40962-020-00455-w ◽

2020 ◽

Vol 14 (4) ◽

pp. 1183-1194

Author(s):

A. Kutz ◽

P. Martin ◽

A. Bührig-Polaczek

Keyword(s):

Fatigue Resistance ◽

Ductile Iron ◽

Fatigue Testing ◽

Fatigue Properties ◽

Graphite Layer ◽

Iron Matrix ◽

Experimental Procedure ◽

Microstructural Defect ◽

Casting Skin ◽

Iron Castings

Abstract Graphite degeneration is the most prominent microstructural defect in the casting skin of ductile iron. Induced by either sulfur or oxygen contained in the molding material, its occurrence can be observed in a large range of iron castings, having substantial negative influences on the mechanical properties, especially fatigue resistance. Previous investigations predominately focused on the influence of the degenerated graphite layer, while accompanying changes of the iron matrix were neglected. The superposition of these effects hinders the evaluation of casting skin defects in state-of-the-art design of ductile iron components. The presented solution utilizes an experimental procedure, which enables the production of specimens with specific, individual microstructural configurations in the casting skin. This approach is based on the application of a modified sand core coating. By adding sulfurizing additives to the coating and adjusting its binder content and viscosity, a predominately homogeneous degenerated layer of 0.5 mm thickness was obtained. Using specific heat treatment steps assured a fully ferritic or pearlitic iron matrix, isolating the degenerated layer as the main microstructural defect. Fatigue testing of these specimens will further enable the numerical evaluation of the fatigue resistance in dependence of the casting skin microstructure.

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