scholarly journals Fatigue Performance of Recycled Hot Mix Asphalt: A Laboratory Study

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Marco Pasetto ◽  
Nicola Baldo
Keyword(s):  
Experimental Data ◽  
Hot Mix Asphalt ◽  
Design Procedure ◽  
Fatigue Performance ◽  
Dissipated Energy ◽  
Reclaimed Asphalt ◽  
Stiffness Reduction ◽  
Modified Binders ◽  
Gyratory Compaction ◽  
Experimental Data Analysis

The paper introduces and analyses the results of an experimental trial on the fatigue resistance of recycled hot mix asphalt for road pavements. Based on the gyratory compaction and the indirect tensile strength test, the mix design procedure has optimized nine different mixes, considering both conventional limestone and Reclaimed Asphalt Pavement (RAP), the latter used at different quantities, up to 40% by weight of the aggregate. A standard bitumen and two polymer modified binders were used for the production of the mixes. The fatigue study was carried out with four-point bending tests, each one performed at 20°C and 10 Hz. The empirical stiffness reduction method, along with the energy ratio approach, based on the dissipated energy concept, was adopted to elaborate the experimental data. Unaged and aged specimens were checked, to analyse the ageing effects on the fatigue performance. In comparison with the control mixes, produced only with limestone, improved fatigue performance was noticed for the mixtures prepared with RAP, especially when made with polymer modified binders, under both aged and unaged conditions. Both the approaches adopted for the experimental data analysis have outlined the same ranking of the mixes.

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

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
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.

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

2019 ◽  
Vol 11 (13) ◽  
pp. 3752 ◽  
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.

Effect of Specimen Size on Compaction and Volumetric Properties in Gyratory Compacted Hot-Mix Asphalt Concrete Specimens

1996 ◽  
Vol 1545 (1) ◽  
pp. 126-132 ◽  
Author(s):  
Kevin D. Hall ◽  
Satish K. Dandu ◽  
Gary V. Gowda
Keyword(s):  
Asphalt Concrete ◽  
Hot Mix Asphalt ◽  
Asphalt Mixture ◽  
Design Procedure ◽  
Specimen Size ◽  
Binder Content ◽  
Volumetric Properties ◽  
Strong Trend ◽  
Number Of Factors ◽  
Gyratory Compaction

Gyratory compaction is the centerpiece of the Strategic Highway Research Program asphalt mixture design procedure Superpave. A number of factors could potentially affect the behavior of asphalt mixes in the gyratory compactor. One of these is specimen size. Four specimen sizes each of one unmodified and two rubber-modified hot-mix asphalt concrete mixes were compacted in the Superpave gyratory compactor to determine the effect of specimen size on compaction and volumetric properties of the mixes. All specimens were compacted using a 150-mm-diameter mold. Specimens of each of the mix types were prepared using three gradations and three binder contents. Densification curves and plotting number of gyrations versus percent of theoretical maximum density were developed for each mix type/gradation/binder content combination. A strong trend in the densification data was observed, in which curves representing specimen sizes of 3500, 5000, and 6500 g were grouped together, apart from the curve representing a 2000-g specimen size. This trend, the grouping of larger specimen data apart from small specimen data, was also observed in volumetric data (optimum asphalt content, voids in mineral aggregate, and voids filled with asphalt). These trends were observed in most of the mix type/ gradation/binder content combinations. The data presented suggest that for specimens of sufficient size, for example, greater than 3500 g, specimen size does not significantly affect the volumetric or compaction properties of hot mix specimens, which supports the ruggedness of the gyratory compaction procedure.

THE “KVAZAR” PACKAGE FOR PATTERN RECOGNITION AND ITS APPLICATIONS

1993 ◽  
Vol 03 (04) ◽  
pp. 439-444 ◽  
Author(s):  
VLADIMIR S. KAZANTSEV
Keyword(s):  
Experimental Data ◽  
Pattern Recognition ◽  
Data Analysis ◽  
Linear Inequalities ◽  
Processing Data ◽  
Experimental Data Analysis ◽  
Ibm Pc

The package of applied programs named KVAZAR has been elaborated to be used for classification, diagnostic, predicative, experimental data analysis problems. The package may be used in medicine, biology, geology, economics, engineering and some other problems. The algorithmical base of the package is the method of pattern recognition, based on the linear inequalities and committee constructions. Other algorithms are used too. The package KVAZAR is intended to be used with IBM PC AT/XT. The range of processing data is bounded by 40,000 numbers.

A Model for Otolith Dynamic Response with a Viscoelastic Gel Layer

1991 ◽  
Vol 1 (2) ◽  
pp. 139-151
Author(s):  
J.W. Grant ◽  
J.R. Cotton
Keyword(s):  
Mathematical Modeling ◽  
Experimental Data ◽  
Equations Of Motion ◽  
Otolith Organs ◽  
Major Contributor ◽  
Viscoelastic Solid ◽  
Gel Layer ◽  
Element System ◽  
Experimental Data Analysis ◽  
Finite Difference Techniques

The otolith organs were modeled mathematically as a 3-element system consisting of a viscous endolymph fluid in contact with a rigid otoconial layer that is attached to the skull by a gel layer. The gel layer was considered to be a viscoelastic solid, and was modeled as a simple Kelvin material. The governing differential equations of motion were derived and nondimensionalized, yielding 3 nondimensional parameters: nondimensional density, nondimensional viscosity, and nondimensional elasticity. The equations were solved using finite difference techniques on a digital computer. By comparing the model’s response with previous experimental research, values for the nondimensional parameters were found. The results indicate that the inclusion of viscous and elastic effects in the gel layer are necessary for the model to produce otoconial layer deflections that are consistent with physiologic displacements. Future experimental data analysis and mathematical modeling effects should include viscoelastic gel layer effects, as this is a major contributor to system damping and response.

scholarly journals Experimental Data Analysis During Initial In-DEBS Operation

2019 ◽  
Vol 17 (S) ◽  
pp. 81-95
Author(s):  
Young-Chul Choi ◽  
Won-Jin Cho ◽  
Jae Owan Lee ◽  
Geon Young Kim
Keyword(s):  
Experimental Data ◽  
Data Analysis ◽  
Experimental Data Analysis
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