scholarly journals Dynamic Characteristics of Warm Mix Foamed Asphalt Mixture in Seasonal Frozen Area

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Yun Hou ◽  
Yanxia Cai ◽  
Zhishu Zang ◽  
Zhenyu Qian ◽  
Bin Zhao

In order to study dynamic characteristics of warm mix foamed asphalt mixture in seasonal frozen area, cylinder dynamic modulus test of four kinds of mixture with two gradations and three kinds of asphalt was carried out by UTM-100. Then, the effects of test temperature, loading frequency, and foaming water consumption on dynamic modulus were analyzed. Finally, the compressive resilient modulus trial was made to compare mechanical properties. Results show that dynamic modulus for warm mix foamed asphalt mixture increases with rising temperature and decreased frequency. The inflection points of the dynamic modulus vs frequency curves at low temperature, normal temperature, and high temperature are 2 Hz, 10 Hz, and 15 Hz, respectively. Static modulus of SBS# modified and nonmodified warm mix foamed asphalt mixture is corresponding to the dynamic modulus 0.001 Hz–0.1 Hz and 0.00001 Hz–0.05 Hz. The effect on gradation type on the dynamic modulus of asphalt mixture is AC-20 > AC-13, and the degree of sensitivity of the water consumption to the master curve equation of dynamic modulus under different gradations is AC-13 > AC-20.

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Muhammad Irfan ◽  
Asad S. Waraich ◽  
Sarfraz Ahmed ◽  
Yasir Ali

This research characterizes the performance of various plant-produced asphalt concrete mixtures by dynamic modulus|E∗|test using asphalt mixture performance tester (AMPT). Marshall designed specimens of seven different mixtures were prepared using the Superpave gyratory compactor and subjected to sinusoidal compressive loading at various temperatures (4.4 to 54.4°C) and loading frequencies (0.1 to 25 Hz). A catalog of default dynamic modulus values for typical asphalt concrete mixtures of Pakistan was established by developing stress-dependent master curves separately, for wearing and base course mixtures. The sensitivity of temperature and loading frequency on determination of dynamic modulus value was observed by typical isothermal and isochronal curves, respectively. Also, the effects of various variables on dynamic modulus were investigated using statistical technique of two-level factorial design of experiment. Furthermore, two dynamic modulus prediction models, namely, Witczak and Hirsch, were evaluated for their regional applicability. Results indicated that both the Witczak and Hirsch models mostly underpredict the value of dynamic modulus for the selected conditions/mixtures. The findings of this study are envisaged to facilitate the implementation of relatively new performance based mechanistic-empirical structural design and analysis approach.


Author(s):  
Shaban Ismael Albrka Ali ◽  
Riyadh Abdulwahid ◽  
Muhamed Laith Eidan ◽  
Nur Izzi Md Yusoff

Flexible pavements deteriorate and crack with time due to the frequent traffic load imposed upon it. Many studies have been done to predict the effects of frequent traffic load and environmental conditions on pavements in the effort to find the best pavement design which resist deterioration and ensure longer pavement service time. This study investigates the effect of mixing asphalt with varying percentages of nano calcium carbonate (CaCO3), namely 0, 2, 4, and 6 %. The mixtures were designed based on the Superpave mix design criteria. Investigation was done using several tests, namely resilient modulus, indirect tensile strength, moisture susceptibility, and dynamic modulus tests. Samples were subjected to aging to determine their resilient modulus. The results of the investigation show that resilient modulus and indirect tensile strength increased when higher percentages of nanoparticles were added to asphalt mixture, with improvement of 138 and 48.18% respectively. Modified binders showed up to 17% improvement in moisture susceptibility comparison to base asphalt mixture, while the result of dynamic modulus test showed that the stiffness of modified asphalt increased 76.69%. The investigation also found that adding 6% CaCO3 nanoparticles to asphalt produced modified asphalt with the best performance. In addition, the results show that the modified asphalt with CaCO3 is suitable for hot and humid regions (tropical countries) in the field of highways construction, as the modifier was able to mitigate the influences of high-temperature rutting and moisture damage.


2014 ◽  
Vol 599 ◽  
pp. 244-247 ◽  
Author(s):  
Qun Shan Ye ◽  
Chang Jian Ye ◽  
Zhi Lin Sun

Viscosity test, dynamic shear test, dynamic modulus test and creep test were conducted to investigate the rheological properties of high modulus asphalt and its mixture. Test results indicated that the viscosity of hard grade asphalt could be increased when compared with the ordinary asphalt, especially at high temperatures. The complex shear modulus and dynamic modulus of hard-grade asphalt binder and its mixture were increased, which implied that the stiffness of them was enhanced. Furthermore, the elastically portions for viscoelastic property of asphalt binders were increased, which resulted in the reduction of phase angle for hard grade asphalt binders and mixtures. The rutting parameter for hard-grade asphalt mixture was increased remarkably, which revealed that the resistance to permanent deformation could be significantly improved for hard grade asphalt mixture.


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.


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.


2021 ◽  
Vol 248 ◽  
pp. 01025
Author(s):  
Zhang Yongjie

water stability of warm mix asphalt mixture based on foamed asphalt is the key evaluation index affecting its road performance. The moisture content in the production process of foamed asphalt is unfavorable to the water stability of warm mix asphalt mixture. In order to improve its water stability, through immersion Marshall test and freeze-thaw splitting test, taking foaming effect, asphalt temperature, foaming water consumption and polymer fiber content as influencing factors, the control variable method is used to study and analyze the influence of factors on the water stability of warm mix asphalt mixture. The test results show that the foaming effect of asphalt, asphalt temperature, foaming water consumption and fiber content are the direct factors affecting the water stability of warm mix asphalt mixture. According to the importance analysis of random forest variables, foaming water consumption, foaming effect and asphalt temperature are the most important variables, while fiber content is the least. Taking the asphalt used in this paper as an example, it is suggested to improve the water stability of warm mix asphalt mixture with the combination of the best foaming effect, asphalt temperature 155 °C, foaming water consumption 2% and fiber content 0.3%.


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.


2019 ◽  
Vol 9 (13) ◽  
pp. 2747 ◽  
Author(s):  
Hui Wang ◽  
Shihao Zhan ◽  
Guojun Liu

Asphalt migration is one of the significant detrimental effects on asphalt pavement performance. In order to simulate the state after the occurrence of asphalt migration amid asphalt pavement layers and further investigate the effects of asphalt migration on the dynamic modulus of asphalt mixture, samples with different asphalt contents layers were firstly separated into the upper and lower half portions and then compacted together. By conducting the dynamic modulus test with the Superpave Simple Performance Tester (SPT), the variation laws of the dynamic modulus (|E*|) and the phase angle (δ) at different testing temperatures and loading frequencies were analyzed in this paper. Further, the dynamic modulus and the stiffness parameter (|E*|/sinδ) at the loading frequency of 10 Hz and testing temperature of 50 °C were illustrated. Simultaneously, the master curves of the dynamic modulus and phase angle of asphalt mixtures under different testing conditions were constructed to better investigate the effects of asphalt migration on the dynamic modulus by means of Williams–Landel–Ferry (WLF) equation and Sigmoidal function. Results show that, after the asphalt migration, the dynamic modulus of asphalt mixtures increase with the increasing loading frequency while they decrease with the increasing testing temperature; the dynamic modulus and the stiffness parameter are the highest when asphalt mixtures have the optimum asphalt content layers, and then decrease with the incremental difference of asphalt content in the upper and lower half portions. Besides this, different from the master curves of dynamic modulus, the master curves of phase angle firstly increase with the increase of loading frequency to the highest point and then decrease with the further increase of loading frequency and are not as smooth as that of dynamic modulus. It can be concluded that the asphalt migration has compromised the mixture’s mechanical structure, and the more asphalt migrates, the weaker the mechanical properties of asphalt mixture will be. Additionally, based on the shift factors and master curves in the time–temperature superposition principle (TTSP), the effects of asphalt migration on the dynamic modulus and the variation laws of the dynamic modulus of asphalt mixture after the occurrence of asphalt migration can be better construed at the quantitative level.


Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1133 ◽  
Author(s):  
Senja Rum Harnaeni ◽  
Florentina Pungky Pramesti ◽  
Arif Budiarto ◽  
Ary Setyawan ◽  
Muhammad Imran Khan ◽  
...  

The aim of this study is to assess the viscoelastic parameters (i.e., phase angle and dynamic modulus) of asphalt concrete-wearing course (AC-WC) and hot rolled sheet-wearing course (HRS-WC) mixtures obtained from the dynamic modulus test. This study was accomplished in four stages: determining optimum asphalt content using Marshall mix design procedure, stability and flow parameters from Marshall test, viscoelastic parameters from dynamic modulus testing and finally the generation of dynamic modulus master curves at a reference temperature of 25 °C. The results showed that at the same temperature, the dynamic modulus of AC-WC and HRS-WC mixtures tended to increase with escalating the loading frequency, while dynamic modulus decreases with an increase in the test temperature at constant loading frequency. Furthermore, the dynamic modulus of the AC-WC mixture was recorded as 100% higher than the HRS-WC asphalt mixture. The phase angle, however, showed contradictory behavior with that shown in dynamic modulus. The phase angle of the AC-WC mixture and HRS-WC asphalt mixture showed almost the same behavior. Similarly, the dynamic modulus master curves of AC-WC and HRS-WC asphalt mixtures can be used to predict the dynamic modulus at the frequency range of 0.01 to 10 Hz and a reference temperature of 25 °C. The results were also used to evaluate the rutting and fatigue performance of AC-WC and HRS-WC.


2018 ◽  
Vol 142 ◽  
pp. 02002
Author(s):  
Junxiao Li ◽  
Wei Fu ◽  
Hechao Zang

Through foaming experiment of Zhongtai AH-70 asphalt, the best foaming temperature water consumption and influence factors of foamed asphalt’s foaming features are determined; By designing the proportion of foamed asphalt cold in-place recycled mixture combined with the water stability experiment, for this mixture the best foamed asphalt addition is 3%, and proportion of the mixture is RAP: fine aggregate: cement=75:23:2. Using SEM technology, the mechanism of increasing on the intensity of foamed asphalt mixture resulted by the addition of cement was analysed. This research provides reference for cement admixture’s formulation in the designing of foamed asphalt cold in-place recycled mixture.


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