Determination of Dynamic Modulus Master Curve of Damaged Asphalt Pavements for Mechanistic–Empirical Pavement Rehabilitation Design

2021 ◽  
pp. 036119812199670
Author(s):  
Zhe “Alan” Zeng ◽  
Kangjin “Caleb” Lee ◽  
Youngsoo Richard Kim
Keyword(s):  
Dynamic Modulus ◽  
Master Curve ◽  
Pavement Design ◽  
Asphalt Pavements ◽  
Levels Of Analysis ◽  
Damage Factor ◽  
Master Curves ◽  
Pavement Rehabilitation ◽  
Design Guide ◽  
Level 1

For pavement rehabilitation design, the current mechanistic–empirical (ME) pavement design guide provides three levels of analysis methodology to determine dynamic modulus master curves for existing asphalt pavements. First, the ME pavement design guide recommends that Witczak’s predictive equation is employed to obtain the “undamaged” modulus master curve. Depending on the chosen level of analysis, either a falling weight deflectometer test (Level 1) or a condition survey (Levels 2 and 3) is conducted to determine the damage factor(s). The damage factor is used to shift the undamaged master curve downward to match the field conditions and obtain the “damaged” master curve. In this study, two pavement structures in North Carolina Highway 96 were selected to evaluate the accuracy of the ME pavement design guide using its three levels of analysis. Because this roadway is a multilayer full-depth pavement, the extracted field cores were divided into a top layer, bottom layer, and total core for investigative and comparative purposes. Accordingly, both laboratory measurements and pavement ME predictions of the dynamic modulus values were conducted separately. Results show that the predicted undamaged master curves are always higher than the measured master curves and Levels 1, 2, and 3 can each lead to significantly different damaged master curves. Considering both efficiency and accuracy for transportation agency practice, the Level 1 method is recommended, and if the existing pavement is a multilayered asphalt pavement, a total core extracted from all the layers is recommended to generate the input properties for Witczak’s predictive equation.

scholarly journals Application of FWD data in developing dynamic modulus master curves of in-service asphalt layers

2017 ◽  
Vol 23 (5) ◽  
pp. 661-671 ◽  
Author(s):  
Nader SOLATIFAR ◽  
Amir KAVUSSI ◽  
Mojtaba ABBASGHORBANI ◽  
Henrikas SIVILEVIČIUS
Keyword(s):  
Dynamic Modulus ◽  
Master Curve ◽  
Asphalt Pavements ◽  
Falling Weight Deflectometer ◽  
Master Curves ◽  
Simple Method ◽  
High Frequencies ◽  
Design Guide ◽  
Falling Weight

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) simplicity in directly constructing in-situ dynamic modulus master curve; (2) developing in-situ master curve in the same trend with the main predicted one; (3) covering the large differences between in-situ and predicted master curve in high frequencies; and (4) the value obtained for the in-situ dynamic modulus is the same as the value measured by the FWD for a corresponding frequency.

Practical Procedure for Developing Dynamic Modulus Master Curves for Pavement Structural Design

2005 ◽  
Vol 1929 (1) ◽  
pp. 208-217 ◽  
Author(s):  
Ramon Bonaquist ◽  
Donald W. Christensen
Keyword(s):  
Asphalt Concrete ◽  
Structural Design ◽  
Dynamic Modulus ◽  
Master Curve ◽  
Performance Test ◽  
Test System ◽  
Pavement Design ◽  
Master Curves ◽  
Practical Procedure ◽  
Testing Sequence

A dynamic modulus master curve for asphalt concrete is a critical input for flexible pavement design in the mechanistic–empirical pavement design guide developed in NCHRP Project 1–37A. The recommended testing to develop the modulus master curve is presented in AASHTO Provisional Standard TP62–03, Standard Method of Test for Determining Dynamic Modulus of Hot-Mix Asphalt Concrete Mixtures. It includes testing at least two replicate specimens at five temperatures between 14°F and 130°F (–10°C and 54.4°C) and six loading rates between 0.1 and 25 Hz. The master curve and shift factors are then developed from this database of 60 measured moduli using numerical optimization. The testing requires substantial effort, and there is much overlap in the measured data, which is not needed when numerical methods are used to perform the time–temperature shifting for the master curve. This paper presents an alternative to the testing sequence specified in AASHTO TP62–03. It requires testing at only three temperatures between 40°F and 115°F (4.4°C and 46.1°C) and four rates of loading between 0.01 and 10 Hz. An analysis of data collected using the two approaches shows that comparable master curves are obtained. This alternative testing sequence can be used in conjunction with the simple performance test system developed in NCHRP Project 9–29 to develop master curves for structural design.

Evaluation of the Response Analysis Approach Used in the Mechanistic-Empirical Pavement Design Guide

2020 ◽  
pp. 036119812097401
Author(s):  
Guozhi Fu ◽  
Yanqing Zhao ◽  
Wanqiu Liu ◽  
Changjun Zhou
Keyword(s):  
Phase Angle ◽  
Dynamic Modulus ◽  
Master Curve ◽  
Compressive Strain ◽  
Pavement Design ◽  
Base Layer ◽  
Response Analysis ◽  
Rate Dependency ◽  
Rate Dependent ◽  
Design Guide

Asphalt concrete (AC) is a typical viscoelastic material exhibiting rate-dependent behavior. The rate-dependency of AC should be properly taken into consideration in pavement response analysis to accurately evaluate pavement performance and life. In the Mechanistic-Empirical Pavement Design Guide (MEPDG), the dynamic modulus master curve is used to account for the rate-dependency of the dynamic modulus of AC. However, the rate-dependent phase angle is ignored and a constant phase angle of 0 is assumed. The partial characterization of rate-dependent properties of AC in the MEPDG may lead to inaccurate results. This study compares the pavement responses computed using the MEPDG approach and the layered viscoelastic theory (LVET) which utilizes the complex modulus master curve to fully characterize the rate-dependent properties of AC. Typical three-layer pavement structures were analyzed at three temperatures (−10°C, 20°C and 50°C) and four speeds (10, 40, 80 and 120 km/h). The results show that the horizontal tensile stresses at the bottom of cement-treated base layer obtained from the two approaches are almost the same, and for other responses analyzed, the results obtained from the MEPDG approach are larger than those from the LVET approach, especially for the responses in the AC layer. The normalized difference of the vertical compressive strain at the mid-depth of the AC layer between the two approaches can be up to 100% and that for the horizontal tensile strain at the bottom of the AC layer can be more than 50%.

Dynamic Modulus of Western Australia Asphalt Wearing Course

2014 ◽  
Vol 71 (3) ◽  
Author(s):  
Gunawan Wibisono ◽  
Hamid Nikraz
Keyword(s):  
Western Australia ◽  
Dynamic Modulus ◽  
Asphalt Mixtures ◽  
Predictive Equation ◽  
Master Curves ◽  
Time Rate ◽  
Low Frequencies ◽  
Design Guide ◽  
Preliminary Study ◽  
Air Void

In the new AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG), the dynamic modulus |E*| test has been selected to assess the performance of asphalt concretes. The type of test, which relates asphalt mixtures modulus to temperature and time rate of loading, is never used in Western Australia. This paper presents a study on the dynamic modulus of typical Western Australia asphalt mixtures. Five mixtures with 10mm nominal sizes and two types of bitumen classes, i.e. C170 (Pen 60/80) and C320 (Pen 40/60) comply with Main Road Western Australia (MRWA) Specification were used in the research. Mixing and compacting process were carried out according to Austroads methods. The specimens were compacted using a gyratory compactor to achieve 5±0.5% target air void. Testing was performed at four temperatures (4, 20, 40 and 55OC) and six frequencies (25, 10, 5, 1, 0.5, 0.1 and 0.05 Hz). Dynamic modulus and phase angle master curves were generated from the results. The master curves were compared to the curves from Witczak’s predictive equation. From this preliminary study, it was found that the measured values correlated well with the predictive equation except at high temperatures or low frequencies. 

scholarly journals Predict the Phase Angle Master Curve and Study the Viscoelastic Properties of Warm Mix Crumb Rubber-Modified Asphalt Mixture

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5051
Author(s):  
Fei Zhang ◽  
Lan Wang ◽  
Chao Li ◽  
Yongming Xing
Keyword(s):  
Phase Angle ◽  
Dynamic Modulus ◽  
Master Curve ◽  
Loss Modulus ◽  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Asphalt Mixtures ◽  
Master Curves ◽  
Modified Asphalt ◽  
Sigmoidal Model

To identify the most accurate approach for constructing of the dynamic modulus master curves for warm mix crumb rubber modified asphalt mixtures and assess the feasibility of predicting the phase angle master curves from the dynamic modulus ones. The SM (Sigmoidal model) and GSM (generalized sigmoidal model) were utilized to construct the dynamic modulus master curve, respectively. Subsequently, the master curve of phase angle could be predicted from the master curve of dynamic modulus in term of the K-K (Kramers–Kronig) relations. The results show that both SM and GSM can predict the dynamic modulus very well, except that the GSM shows a slightly higher correlation coefficient than SM. Therefore, it is recommended to construct the dynamic modulus master curve using GSM and obtain the corresponding phase angle master curve in term of the K-K relations. The Black space diagram and Wicket diagram were utilized to verify the predictions were consistent with the LVE (linear viscoelastic) theory. Then the master curve of storage modulus and loss modulus were also obtained. Finally, the creep compliance and relaxation modulus can be used to represent the creep and relaxation properties of warm-mix crumb rubber-modified asphalt mixtures.

scholarly journals Measurement of Dynamic Modulus and Master Curve Modeling of Hot Mix Asphalt from Senegal (West Africa)

2015 ◽  
Vol 2 (1) ◽  
pp. 124 ◽  
Author(s):  
Mouhamed Lamine Chérif Aidara ◽  
Makhaly Ba ◽  
Alan Carter
Keyword(s):  
Dynamic Modulus ◽  
Master Curve ◽  
Hot Mix Asphalt ◽  
Complex Modulus ◽  
Test Results ◽  
Asphalt Mixes ◽  
Design Guide ◽  
Asphalt Mix ◽  
Sigmoidal Model ◽  
Curve Modeling

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 R2 = 0,99 and p = 0,00 in STATISTICA software, which allows to conclude that the sigmoidal model has good modeling of the dynamic modulus.

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