Characteristic Analysis of Dynamic Modulus for High Modulus Asphalt Concrete

2014 ◽  
Vol 505-506 ◽  
pp. 15-18 ◽  
Author(s):  
Xiao Long Zou ◽  
Ai Min Sha ◽  
Wei Jiang ◽  
Xin Yan Huang

In order to analyze the characteristics of high modulus asphalt mixture dynamic modulus, Universal Testing Machine (UTM-25) was used for dynamic modulus test of three kinds of mixtures, which were PR Module modified asphalt mixture and PR PLAST.S modified asphalt mixture and virgin asphalt mixture, to investigate dynamic modulus and phase angle at different temperatures and frequencies. The results indicate that: the dynamic modulus order of the three asphalt mixtures is PR MODULE > PR PLAST.S > Virgin. PR MODULE asphalt mixture dynamic modulus is much larger than the other two.

2011 ◽  
Vol 243-249 ◽  
pp. 4220-4225
Author(s):  
Rui Bo Ren ◽  
Li Tao Geng ◽  
Li Zhi Wang ◽  
Peng Wang

To study the mechanical properties of high modulus asphalt mixtures, dynamic modulus and phase angle of these two mixtures are tested with Simple Performance Testing System under different temperatures, loading frequencies and confining pressures. Testing results show the superiority of high modulus asphalt mixture in aspect of high temperature performance. Furthermore, the changing rules of dynamic modulus and phase angle are also discussed.


Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1502
Author(s):  
Licheng Guo ◽  
Qinsheng Xu ◽  
Guodong Zeng ◽  
Wenjuan Wu ◽  
Min Zhou ◽  
...  

In the French high-modulus asphalt mixture design system, the complex modulus of the mixture under the conditions of 15 °C and 10 Hz is taken as the design index. However, in China, the dynamic modulus under the conditions of 15 °C, 10 Hz, 20 °C, 10 Hz and 45 °C, 10 Hz was taken as the stiffness modulus index of high-modulus asphalt mixture. The difference in modulus values between the two systems caused the pavement structure layer to be thicker and the construction cost to be higher in China. In order to find out the appropriate modulus value of high-modulus asphalt mixture suitable for China’s modulus parameter conditions to better carry out the reasonable design and evaluation of high-modulus asphalt mixture in China, the modulus of four types of high-modulus asphalt mixtures under the two systems through the two-point bending complex modulus test of the CRT-2PT trapezoidal beam and the SPT uniaxial compression dynamic modulus test were analyzed in this paper. Under the premise of meeting the stiffness modulus index of the French high-modulus asphalt mixture, the relationship conversion models between the dynamic modulus and complex modulus of high-modulus asphalt mixture under different temperatures were established. According to the conversion models, the design evaluation value range of dynamic modulus suitable for China’s condition was recommended. It is recommended that the dynamic modulus of China’s high-modulus asphalt mixture at 15 °C and 10 Hz is not less than 16,000 MPa, the dynamic modulus at 20 °C and 10 Hz is not less than 14,000 MPa, and the dynamic modulus at 45 °C and 10 Hz is not less than 2500 MPa. Five kinds of high-modulus asphalt mixtures used in actual road engineering were tested to verify the reliability of the recommended dynamic modulus values based on the modulus conversion model, and the results are consistent with the recommended value range of the model.


2011 ◽  
Vol 261-263 ◽  
pp. 824-828 ◽  
Author(s):  
Qian Zhang ◽  
Shu Wei Goh ◽  
Zhan Ping You

The objective of this study is to investigate the possibility of using waste plastic as an additive to modify asphalt mixtures thereby reducing the waste plastic stream in our environment. High density polyethylene plastic bags obtained from the retail store were shredded into chips and added into asphalt mixtures at the rate of 0% (control sample), 2, 5 and 8% based on binder weight. Three different temperatures of 4, 21.3 and 39.2°C and frequencies ranging from 0.1 to 25 Hz were used in the dynamic modulus test. It was found that most of the asphalt mixtures modified with waste plastic have higher dynamic modulus when compared with the control samples. However, no significant trend on phase angle was found among all the samples tested based on the test results. In this study, it was found that the modified asphalt mixture with 2% waste plastic had the highest dynamic modulus and phase angle. Based on the test results, it was found that plastic modified asphalt mixture will have a better performance under intermediate and high temperature conditions.


2011 ◽  
Vol 287-290 ◽  
pp. 1155-1163
Author(s):  
Shao Long Huang ◽  
Fan Shen ◽  
Qing Jun Ding

In this paper, recycled PE was added directly to the asphalt mixture to prepare high modulus asphalt mixture. To study the influence of the dosage and molecular weight of recycled PE on the performance of asphalt mixture, three kinds of recycled PE with different molecular weight and three asphalt binders (Conventional, SBS Modified and PE Modified) were used to prepare eight kinds of asphalt mixture. Various tests, including dynamic modulus, wheel tracking and Lottman test, were conducted to evaluate the performance of them. The results showed that 1) the dynamic modulus of asphalt mixture modified by recycled PE is higher than the normal mixture and mixture prepared with SBS modified asphalt binder; 2) adding recycled PE directly into the asphalt mixture during mixing is more effective than preparing asphalt mixture with PE modified asphalt binder in making high modulus asphalt mixture; 3) the recycled PE used to produce high modulus asphalt mixture should have certain big molecular weight, more than 27,000, and the dosage of recycled PE should be no less than 0.4% of the total weight of asphalt mixture. The performance tests indicted the good high temperature deformation resistance property of asphalt mixture modified by recycled PE.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5051
Author(s):  
Fei Zhang ◽  
Lan Wang ◽  
Chao Li ◽  
Yongming Xing

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Xinquan Xu ◽  
Guilin Lu ◽  
Jun Yang ◽  
Xinhai Liu

High-modulus asphalt concrete (HMAC) is considered as an effective paving material for addressing the increasing heavy traffic and rutting problems. Therefore, one high-modulus agent was used in this study to prepare high-modulus asphalt binder with different dosages. The objective of this study is to investigate the performance and modification mechanism of high-modulus asphalt. The effects of high-modulus agent on the viscoelastic properties of asphalt with different dosages were quantified via rheological tests as compared to base binder and styrene-butadiene-styrene- (SBS-) modified asphalt. Moreover, the modification mechanism of the high-modulus agent was examined using fluorescence microscopy and infrared spectrum test. Based on rutting and dynamic modulus tests, the differences of road performances between high-modulus modified asphalt mixture and SBS-modified asphalt mixture were compared. The results demonstrate that the high-modulus agent improves the high-temperature performance and viscoelastic properties of the matrix asphalt. When the dosage increases to 6.67%, the modification effect is better than that of the SBS-modified asphalt. Furthermore, the results of the rutting test show that the high-modulus modified asphalt mixture has better resistance to deformation than the SBS-modified asphalt mixture. The dynamic modulus test further demonstrates that the high-modulus modified asphalt mixture exhibits superior performance in high-temperature range. Fluorescence microscopy shows that the high-modulus agent particles can swell in the asphalt to form polymer links that improve the viscoelastic properties of the asphalt. Based on the results of the infrared spectrum test, it can be concluded that a high-modulus agent changes the asphalt matrix via physical blending modification.


2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Hui Yao ◽  
Zhanping You

The objectives of this research are to use micro- and nanomaterials to modify the asphalt mixture and to evaluate the mechanical performance of asphalt mixtures. These micro- and nanomaterials, including carbon microfiber, Nanomer material, nanosilica, nonmodified nanoclay, and polymer modified nanoclay, were selected to blend with the control asphalt to improve the overall performance of the modified asphalt binders and mixtures. The microstructures of original materials and asphalt binders were observed by the field emission scanning electron microscope (FE-SEM). The mixture performance tests were employed to evaluate the resistance to rutting and permanent deformation of the modified asphalt mixtures. Test results indicate that(1)the dynamic modulus of micro- and nanomodified asphalt mixtures improved significantly;(2)the rutting susceptibility of the modified asphalt mixtures was reduced significantly compared to that of the control asphalt mixture;(3)the microstructures of modified asphalt binders were different from the control asphalt, and the structures determine the improvement in the performance of modified asphalt mixtures. These results indicate that the addition of micro- and nanomaterials enhanced the rutting performance and strength of asphalt mixtures. In addition, the analysis of variance (ANOVA) was used to analyze the modifying effects of micro- and nanomaterials on the performance.


2021 ◽  
Author(s):  
Jan Valentin ◽  
Majda Belhaj ◽  
Pavla Vacková

High modulus asphalt concrete (HMAC) presents a concept of an asphalt mixture with advanced performance which is suitable mainly for heavy loaded pavement structures. The mix concept was developed more than 25 years ago in France and became a standard in many countries. In the Czech Republic this type of asphalt mixtures is used since the early years of this millennium, when original technical requirements have been set. After almost 20 years a volunteer technical assessment started to validate whether the technical requirement set mainly for stiffness values and partly also for flexural strength or resistance to crack propagation are still up-to-date or if some reasonable modification is needed like was done several years ago in France when high modulus asphalt concrete of so called EME II or GP5 generation were brought to the practice. Based on this a study with focus on stiffness determination for more than 40 different HMACs was started. The stiffness was tested at different temperatures. At the same time virgin and aged asphalt mixtures were compared. Results from this study are presented by the paper.


2011 ◽  
Vol 243-249 ◽  
pp. 4226-4230
Author(s):  
Li Tao Geng ◽  
Rui Bo Ren ◽  
Li Zhi Wang ◽  
Cui Lan Gao

Two types of high modulus asphalt mixtures are introduced. Dynamic modulus and phase angle of these two mixtures are tested with Simple Performance Testing System under different temperatures, loading frequencies and confining pressures. Based on time-temperature superposition principle, dynamic modulus master curves and time-temperature shift factors at reference temperature are obtained using nonlinear square least square regression, and phase angle master curves are constructed utilizing the same time-temperature shift factors. The influence of confining pressure on mechanical properties of high modulus asphalt mixture is discussed.


Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1321
Author(s):  
Sanqiang Yang ◽  
Shuang Sun ◽  
Lusheng Qin ◽  
Qian Li

The applications of rubber-modified asphalt and its mixtures have received widespread attention due to the environmental and economic benefits of such materials. However, studies on the structural performance of rubber-powder-modified asphalt pavement are only concentrated on a certain scale, leading to research on the structural performance of pavement mostly focusing on mechanical responses at a macro scale. Therefore, the present study adopts the concept of multi-scale research to analyze the viscoelasticity of high-dosage-modified asphalt and its mixtures at a microscopic scale from the perspective of meso-mechanical analysis. In this paper, to ensure the overall durability of a structure, the effective asphalt film thickness and coarse aggregate angularity index of the test material were measured first. The viscoelasticity of asphalt modified with rubber powder was then analyzed using a Brinell viscosity test, scanning electron microscopy (SEM), and a dynamic shear rheometer (DSR). We determined the optimal amount of rubber powder to be 30%. A universal testing machine was used to study the influence of different temperatures and loading frequencies on the viscoelastic properties of different asphalt mixtures. Research on the dynamic modulus found that the incorporation of rubber powder increases the elastic properties of the mixture such that the rubber-powder-modified asphalt mixture had a higher dynamic modulus. At the same time, the high-dosage-modified asphalt mixture was found to be closer to an elastomer under a low temperature and high frequency. At a high temperature and low frequency, the asphalt mixture changed into a viscoelastic body whose viscous properties were mainly affected by the asphalt binder. The addition of rubber powder changed the temperature sensitivity of the asphalt and then affected the viscoelastic properties of the asphalt mixture.


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