Evaluation of different procedures and models for the construction of dynamic modulus master curves of asphalt mixtures (original) (raw)
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Studies in Engineering and Technology, 2015
The main purpose of this paper is to model the master curve of dynamic modulus |E*| for Hot Mix Asphalt mix designed with aggregate from Senegal named basalt of Diack and quartzite of Bakel. The prediction model used is the Witczak model, used in the Mechanistic-Empirical Pavement Design Guide. A study has been conducted in the Laboratory of Pavements and Bituminous Materials. Six different HMA (BBSG 0/14 mm) were subjected to complex modulus test by tension-compression according to the European or Canadian procedure using the same range of temperatures and frequencies. For each mixture studied the uniqueness of modulus curves in the Cole-Cole or in Black diagrams have shown that the asphalt mixes are thermorheologically simple materials and the Canadian test process is suitable for determining the HMA complex modulus mix designed with the aggregates from Senegal. This implies their tender with the principle of time-temperature equivalence. The test results were used to model the master curves of HMA studied. A correlation with the results of dynamic modulus measured have shown an accuracy of R 2 = 0,99 and p = 0,00 in STATISTICA software, which allows to conclude that the sigmoidal model has good modeling of the dynamic modulus.
Materials
Dynamic modulus master curves are usually constructed by using sigmoid functions, but the coefficients of these functions are not independent of each other. For this reason, it is not possible to clearly identify their physical mean. Another way of describing the dynamic modulus master curves is to choose the Ramberg-Osgood (RAMBO) material model, which is also well-suited for modelling the cyclic behaviour of soils. The Ramberg-Osgood model coefficients are completely independent of each other, so the evaluation of the fitted curve is simple and straightforward. This paper deals with the application of the Ramberg-Osgood material model compared to the usual techniques for constructing a master curve, determining the accuracy in describing the material behaviour of asphalt mixtures, and seeking any surplus information that cannot be derived by traditional techniques. Because the dynamic modulus and phase angle master curves are strictly related, in the present study, the asymmetric ...
International Journal of Pavement Engineering, 2011
This paper describes an abbreviated testing temperature (ABBREV) approach for developing dynamic modulus (|E*|) master curves for hot-mix asphalt (HMA). The ABBREV approach uses three instead of the five standard temperatures required under AASHTO TP 62. Testing at the lowest and highest temperatures as specified under AASHTO TP 62 is not required. Potential savings in testing time were a key motivation for the study. Using a database of |E*| from up to 36 HMA mixtures, we developed regression models to estimate the |E*| at the lowest and highest testing temperatures. By combining the predicted |E*| at the lowest and highest temperatures with measured |E*| at intermediate temperatures (4, 21 and 38°C), we found the ABBREV master curves to be comparable with those of AASHTO TP 62. The results suggest that |E*| master curve for HMA could be developed without the need to conduct tests at the lowest and highest testing temperatures recommended under AASHTO TP 62.
Developing Master Curves for Asphalt Pavement
—The complex moduli relationship related mixture moduli to temperature and time rate of loading has been an integral part of several mechanistic-empirical (ME) design procedures used throughout of the world. Seven asphalt concrete mixtures of different types of polymer modified binders (PMB) were produced in a laboratory to modify performance of asphalt mixture. The main role of this research is to evaluate the influence of these polymer modifiers on the pavement performance of asphalt mixture with the dynamic modulus, |E*| of hot-mix asphalt (HMA) mixture indicator in a laboratory test for Mainroad Western Australia and Fulton Hogan. In this study, the influence of temperature, loading frequency, and confining pressure on the dynamic characteristic of asphalt mixture were analysis, master curves of dynamic modulus of HMA mixtures were developed and data's were interpreted. Results showed that AC10 5.7% A35P (EVA) M7 B5, AC10 5.7% C450 M10 B5 and AC10 Multi 600/700 M5 B4 mixes method were the more efficient and effective in all categories of asphalt performance measures for strength and durability of HMA as compared to others polymer modifiers. A very good correlation (R 2 = 1) was found for each polymer modifier. This suggested that laboratory test using a various temperatures and loading frequencies can improve pavement mix design, lab and field control and assurance. A strong correlation between binder viscosity and temperature [R 2 = 1] for polymer modified asphalt mixture.
Application of FWD data in developing dynamic modulus master curves of in-service asphalt layers
Journal of Civil Engineering and Management
This paper presents a simple method to determine dynamic modulus master curve of asphalt layers by conducting Falling Weight Deflectometer (FWD) for use in mechanistic-empirical rehabilitation. Ten new and rehabilitated in-service asphalt pavements with different physical characteristics were selected in Khuzestan and Kerman provinces in south of Iran. FWD testing was conducted on these pavements and core samples were taken. Witczak prediction model was used to predict dynamic modulus master curves from mix volumetric properties as well as the bitumen viscosity characteristics. Adjustments were made using FWD results and the in-situ dynamic modulus master curves were obtained. In order to evaluate the efficiency of the proposed method, the results were compared with those obtained by using the developed procedure of the state-of-the-practice, Mechanistic-Empirical Pavement Design Guide (MEPDG). Results showed the proposed method has several advantages over MEPDG including: (1) s...
Dynamic Master Curves of Polymer Modified Asphalt from Three Different Geometries
2000
Polymer modified asphalt is highly temperature sensitive material. To obtain the master curves of dynamic material functions, for this material, one has to perform the testing over the temperature interval from -30 o C to at least 90 o C. Since the polymer modified asphalt undergoes the transition from a glass-like to the Newtonian-like material, in this temperature range, the
Effect of Asphalt Mixture Components on the Uncertainty in Dynamic Modulus Mastercurves
Transportation Research Record, 2020
Practitioners and researchers in the paving industry have highlighted the importance of the adoption of reliability-based pavement design. The goal of developing reliable pavements with optimum performance over their design life has become a key factor to be considered during both pavement design and construction processes. This requires the adoption of statistical and probabilistic-based analyses for the formulation of the properties and behavior of pavement materials. Thus, many researchers worked on the quantification and modeling of the uncertainty caused by the inherent variability in pavement materials in general and that of asphalt concrete (AC) in particular. The dynamic modulus (|E*|), a fundamental property for mechanistic-empirical and purely mechanistic pavement designs, has been proven to have a significant level of uncertainty that is dependent on climatic and traffic loading conditions. The main objective of this study is to investigate the effect of the AC mixture properties and components on the uncertainty in the |E*| mastercurve. This objective is achieved by conducting an experimental program incorporating four different mixtures having the same material sources but different binder types and gradations. Monte Carlo simulations are used to model the uncertainty of |E*| for each of these mixtures. The paper shows that the uncertainty is dependent on mixture type, as the presence of larger nominal maximum aggregate size, modified binder, or additive can increase the uncertainty in the |E*| mastercurve, especially at high temperatures or slow loading rates. The uncertainty is proven to be material related and not imposed by the testing instrumentation.
Resilient modulus master curve for BRA-modified asphalt mixtures
Roads and bridges - Drogi i mosty, 2020
The objective of this research was to evaluate the impact of using granular Buton Rock Asphalt (BRA) modifier binder in asphalt mixtures, based on the developed resilient modulus master curve. This involved laboratory evaluation of indirect tensile stiffness modulus (ITSM) on UTM25 test equipment in accordance with the Australian Standard AS2891.13.1-1995. The test was applied to dense-graded (10 mm) unmodified and BRA-modified asphalt mixtures at five different test temperatures: 5°C, 15°C, 25°C, 40°C and 60°C and three different loading frequencies: 0.33 Hz, 0.50 Hz and 1.0 Hz. The results showed that in the high-intermediate temperature range and at low frequency the resilient modulus of BRA-modified asphalt mixtures was higher than the modulus of unmodified mixtures. It was discovered that the viscoelastic behavior of BRA-modified asphalt mixtures was more pronounced than in the case of unmodified asphalt mixtures.
International Journal of Engineering and Technology, 2015
The complex moduli relationship related mixture moduli to temperature and time rate of loading has been an integral part of several mechanistic-empirical (M-E) design procedures used throughout of the world. Seven asphalt concrete mixtures of different types of polymer modified binders (PMB) were produced in a laboratory to modify performance of asphalt mixture. The main role of this research is to evaluate the influence of these polymer modifiers on the pavement performance of asphalt mixture with the dynamic modulus, |E*| of hot-mix asphalt (HMA) mixture indicator in a laboratory test for Mainroad Western Australia and Fulton Hogan. In this study, the influence of temperature, loading frequency, and confining pressure on the dynamic characteristic of asphalt mixture were analysis, master curves of dynamic modulus of HMA mixtures were developed and data's were interpreted. Results showed that AC10 5.7% A35P (EVA) M7 B5, AC10 5.7% C450 M10 B5 and AC10 Multi 600/700 M5 B4 mixes method were the more efficient and effective in all categories of asphalt performance measures for strength and durability of HMA as compared to others polymer modifiers. A very good correlation (R 2 = 1) was found for each polymer modifier. This suggested that laboratory test using a various temperatures and loading frequencies can improve pavement mix design, lab and field control and assurance. A strong correlation between binder viscosity and temperature [R 2 = 1] for polymer modified asphalt mixture.
Analytical Modelling of Visco-Elastic Behaviour of Hot-MIX Asphalt
2012
As part of the revision of the South African Pavement Design Method (SAPDM), laboratory testing was conducted to obtain the dynamic (Complex) modulus |E*| of hot-mix asphalt (HMA) samples. Dynamic modulus gives an indication of linear visco-elastic (LVE) behaviour of HMA materials at different temperatures and loading frequencies; and is required for computation of stresses, strains and displacements in flexible pavement analysis and design. Laboratory tests to obtain dynamic modulus are normally conducted at limited range of temperatures and loading frequencies. In order to characterize HMA mixes for pavement analysis, sigmoidal function master curves are constructed at different temperatures and loading frequencies using a time-temperature superposition principle. Instead of using the sigmoidal function, this paper presents an alternative approach for characterising the LVE behaviour of HMA materials. This approach is based on the use of three rheological models, namely, Burger's, Huet-Sayegh and the generalised 2S2P1D. The model parameters for all three rheological models were successfully determined. The master curves were developed for all HMA mixes studied. The Cole-Cole and the Black diagrams were determined. Based on the results presented in this paper, the Huet-Sayegh and the Generalised 2S2P1D models appear to predict the LVE behaviour of HMA mixes more effectively than the Burger's model.