Preliminary Evaluation of Field Aging Characteristic of Warm Mix Asphalt

2013 ◽  
Vol 723 ◽  
pp. 149-156 ◽  
Author(s):  
Shih Hsien Yang ◽  
Anthony Keita
Keyword(s):  
Resilient Modulus ◽  
Warm Mix Asphalt ◽  
Preliminary Evaluation ◽  
Dynamic Shear ◽  
Complex Shear Modulus ◽  
Weather Information ◽  
Indirect Tensile Test ◽  
Complex Shear ◽  
Indirect Tensile

This study is aimed at evaluating the rate of long-term aging of WMA compared to conventional hot-mix-asphalt (HMA). A test section with recorded traffic and weather information was designated in this study. Field cores of two WMAs and one conventional HMA were taken from the field periodically. Both mix and binder properties of retrieved were measured in the laboratory. The resilient modulus and indirect tensile test were performed to characterize mixture properties. The rheological properties of extracted binder were measured by the dynamic shear rheometer (DSR) in order to obtain the complex shear modulus (G*) as well as the phase angle (δ) of binder with and without the WMA additives.

Research on Performance of Sasobit Warm Mix Asphalt and Influence of Aging Using DSR

2011 ◽  
Vol 128-129 ◽  
pp. 426-429 ◽  
Author(s):  
Hai Zhao
Keyword(s):  
Shear Modulus ◽  
Phase Angle ◽  
Warm Mix Asphalt ◽  
Dynamic Shear ◽  
Complex Shear Modulus ◽  
Dynamic Shear Rheometer ◽  
Complex Shear

In order to study the performance of Sasobit warm mix asphalt and the influence of aging, complex shear modulus G* and phase angle δ of Sasobit warm mix asphalt are tested by Dynamic Shear Rheometer （DSR） at different aging phase, to analyze the effects of Sasobit to the performance and the aging of 70# and SBS asphalt. The results show that with the increasing of the dosage of Sasobit, the value of G*/sinδ can be increased at different aging phase, the change in the phase angle has the same trend; the degree of Long-term aging of warm-matrix asphalt is larger than modified asphalt's. This may be related to the interaction of Sasobit and modifier.

scholarly journals Stiffness Modulus of Asphaltic Concrete Incorporating Coir Fibre and Subjected to Aging

2018 ◽  
Vol 65 ◽  
pp. 02003
Author(s):  
Abdullahi Ali Mohammed ◽  
Ramadhansyah Putra Jaya ◽  
Étienne Joseph Marie Delbrel ◽  
Choong Wee Kang ◽  
Sien Ti Kok ◽  
...  
Keyword(s):  
Stiffness Modulus ◽  
Modified Asphalt ◽  
Indirect Tensile Test ◽  
Coir Fibre ◽  
Performance Response ◽  
Short And Long Term ◽  
Indirect Tensile ◽  
Repeated Load ◽  
The Impact

The aim of this paper is to investigate the performance response of a set of coir fibre modified asphalt samples subjected different ageing conditions and containing three different fibre contents. The laboratory experimental programs are indirect tensile test at 25°C and repeated load axial test at 40°C. The results showed that the fibres improved the mixture’s performance. The main findings obtained at 25°C for short and long-term ageing reveal that low fibre content at around 0.3% per aggregate weight display a stiffness modulus up to 14% higher than that of unmodified mixtures, hence showing that fibres may improve the bearing capacity and rut-resistance of asphalt mixtures. Conversely, as the amount of fibre increases to 0.5% and 0.7%, the stiffness decreases to the point of becoming unacceptably low, almost 80% lower than unmodified mixes stiffness. However the data also reveal that high fibre contents at 0.5% and above completely neutralize the impact of ageing on the mixture, indicating that fibre-modified mixtures would yield longer lives.

Validation of Magnetic Resonance Elastography by Dynamic Shear Testing in the Shear Wave Regime

2010 ◽  
Author(s):  
Ruth J. Okamoto ◽  
Erik H. Clayton ◽  
Kate S. Wilson ◽  
Philip V. Bayly
Keyword(s):  
Magnetic Resonance ◽  
Shear Modulus ◽  
Shear Wave ◽  
Shear Force ◽  
Magnetic Resonance Elastography ◽  
Dynamic Shear ◽  
Complex Shear Modulus ◽  
Shear Testing ◽  
Complex Shear ◽  
Propagating Shear

Magnetic resonance elastography (MRE) is a novel experimental technique for probing the dynamic shear modulus of soft biological tissue non-invasively and in vivo. MRE utilizes a standard MRI scanner to acquire images of propagating shear waves through a specimen that is subject to external harmonic mechanical actuation; commonly at frequencies in excess of 200Hz. At steady state, the wavelength of the propagating shear wave can be used to estimate the shear modulus of the tissue. Dynamic shear testing (DST) is also used to characterize soft biomaterials. Thin samples of the material are subject to oscillatory shear strains. Shear force is measured, and converted to shear stress — analysis of this data of a range of frequencies gives a complex shear modulus. The data analysis method assumes that the shear displacement is linear and shear strain is constant through the thickness of the sample. In soft tissues, very thin samples are typically used to avoid inertial effects at higher frequencies. As the thickness of the sample decreases, it is more difficult to cut samples of uniform thickness and to maintain structural integrity of the sample. Thus in practice, measurements of brain tissue properties using DST without inertial correction are limited to low frequencies. In this work, we bridge the frequency regimes of DST and MRE by testing thick samples using DST over a range of frequencies that generates a shear wave in the sample, with a corresponding peak in the measured shear force. The frequency and magnitude of this peak give additional information about the complex shear modulus of the material being tested, and these DST results are interpreted using a finite element (FE) model of the sample. Using this method, we can obtain an estimate of shear modulus in an intermediate frequency regime between that of standard DST and MRE.

scholarly journals Influence of Gradation on the Mechanical Properties of Aged Hot-Mix Asphalts

Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 632
Author(s):  
Saieth Baudilio Chaves-Pabón ◽  
Hugo Alexander Rondón-Quintana ◽  
Carlos Alfonso Zafra-Mejía
Keyword(s):  
Mechanical Properties ◽  
Cyclic Load ◽  
Stress Condition ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Short Term ◽  
Clear Trend ◽  
Indirect Tensile ◽  
Effects Of Aging

When a hot-mix asphalt (HMA) ages, its mechanical properties, resistance, and durability change. Several studies have been conducted throughout the world to evaluate the effects of aging in HMAs. However, few studies have analyzed the influence of gradation. The main objective of this study was to evaluate the influence of gradation on the mechanical properties of aged HMA mixes. For such purposes, three HMA mixes with different gradations were manufactured (named HMA-10, HMA-19, and HMA-25), which were conditioned in STOA (short-term oven aging) and LTOA (long-term oven aging) by following the guidelines established by the AASHTO R30 specification. Marshall, Indirect Tensile Strength (ITS), resilient modulus, permanent deformation, fatigue (under controlled-stress condition), and Cantabro tests were performed. These tests were carried out to evaluate resistance under monotonic and cyclic load as well as the resistance to moisture damage and abrasion. The best performing mix in the test was HMA-19. There is no clear trend about the influence of gradation over the susceptibility of mixes for aging. This susceptibility changes depending on the test performed and the property measured. Furthermore, in resilient modulus tests, it is observed that the influence of gradation on aging susceptibility changes depending on the test temperature.

scholarly journals Effect of Aging on the Properties of Asphalt and Asphalt Mixtures

2015 ◽  
Vol 19 (2) ◽  
pp. 89
Author(s):  
Carlos Hernando Higuera Sandoval ◽  
Xiomara Vanessa Camargo Amaya ◽  
Edwin Alexander Suárez Molano
Keyword(s):  
Tensile Test ◽  
Dynamic Modulus ◽  
Work Values ◽  
Asphalt Mixtures ◽  
Indirect Tensile Test ◽  
Aged Asphalt ◽  
Indirect Tensile ◽  
The Stability

This article presents the results of the analysis of the effect of aging on the properties of asphalt and asphalt mixtures. The objective of this study was to compare the properties of the original asphalt and aged asphalt and the dynamic modulus of asphalt mixtures. The long-term aging was simulated by using Pressure Asphalt Vessel (PAV). Marshall and RAMCODES methodologies were used to determine the formula of work; values of dynamic modulus of designed mixtures were obtained by the indirect tensile test, using the Nottingham Asphalt Tester (NAT). The results showed an increase in the rigidity of the aged asphalt. Also, an increase of the stability and a decreased flow in the mixtures made with this type of binder was found. The dynamic modulus values of the mixtures containing aged asphalt showed an increase up to three times compared with those elaborated with original asphalt mixtures.

Viscoelastic Analysis of Asphalt Mastic Based on Micromechanics

2011 ◽  
Vol 266 ◽  
pp. 38-41
Author(s):  
Jiu Peng Zhang ◽  
Li Xu ◽  
Jian Zhong Pei
Keyword(s):  
Shear Modulus ◽  
Chemical Interaction ◽  
Hydrated Lime ◽  
Asphalt Binders ◽  
Dynamic Shear Modulus ◽  
Dynamic Shear ◽  
Complex Shear Modulus ◽  
Asphalt Mastic ◽  
Physico Chemical ◽  
Complex Shear

In this study, the stiffening effect of fillers on asphalt binders was characterized through micromechanics and rheology methods. The dynamic shear rheometer (DSR) was used to measure viscoelastic properties of asphalt mastic. Mechanical volume filling effects and additional interacting mechanisms within mastic systems are discussed on the basis of micromechanics-rheology model to predict the complex shear modulus of asphalt mastic from the measured mastic data. It is observed that the phase angle ranges from 88.8o to 89.0o, does not significantly change due to limestone fillers addition. The analytical model prediction of complex shear modulus based on the dynamic shear modulus can be used. Using the nonlinear regression, the Einstein coefficient KE is 4.22, 5.09 and 7.44 for asphalt mixed with limestone, cement and hydrated lime, respectively. Beside, the SEM results explain why the mastic system with hydrated lime shows the highest KE. The behavior of hydrated lime fillers filled mastics is probably due to physico–chemical interaction, which can be validated by further research.

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