scholarly journals The Discrete and Continuous Retardation and Relaxation Spectrum Method for Viscoelastic Characterization of Warm Mix Crumb Rubber-Modified Asphalt Mixtures

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3723 ◽  
Author(s):  
Fei Zhang ◽  
Lan Wang ◽  
Chao Li ◽  
Yongming Xing
Keyword(s):  
Continuous Spectrum ◽  
Discrete Spectrum ◽  
Creep Compliance ◽  
Relaxation Modulus ◽  
Crumb Rubber ◽  
Asphalt Mixtures ◽  
Time Range ◽  
Modified Asphalt ◽  
Dynamic Modulus Test ◽  
Discrete And Continuous Spectrum

To study the linear viscoelastic (LVE) of crumb rubber-modified asphalt mixtures before and after the warm mix additive was added methods of obtaining the discrete and continuous spectrum are presented. Besides, the relaxation modulus and creep compliance are constructed from the discrete and continuous spectrum, respectively. The discrete spectrum of asphalt mixtures can be obtained from dynamic modulus test results according to the generalized Maxwell model (GMM) and the generalized Kelvin model (GKM). Similarly, the continuous spectrum of asphalt mixtures can be obtained from the dynamic modulus test data via the inverse integral transformation. In this paper, the test procedure for all specimens was ensured to be completed in the LVE range. The results show that the discrete spectrum and the continuous spectrum have similar shapes, but the magnitude and position of the spectrum peaks is different. The continuous spectrum can be considered as the limiting case of the discrete spectrum. The relaxation modulus and creep compliance constructed by the discrete and continuous spectrum are almost indistinguishable in the reduced time range of 10−5 s–103 s. However, there are more significant errors outside the time range, and the maximum error is up to 55%.

scholarly journals Kajian Penambahan RejIRE pada Aspal Modifikasi Crumb Rubber serta Kinerjanya pada Campuran Beraspal Panas

2019 ◽  
Vol 24 (2) ◽  
pp. 148
Author(s):  
Sri Mulyani ◽  
Nono Nono ◽  
Nyoman Suaryana
Keyword(s):  
Heavy Traffic ◽  
Permanent Deformation ◽  
Crumb Rubber ◽  
High Viscosity ◽  
Asphalt Mixtures ◽  
Modified Asphalt ◽  
Low Viscosity ◽  
Styrene Butadiene ◽  
Sbs Modified Asphalt ◽  
Rubber Modification

Asphalt polymer has superior characteristics than conventional asphalt. Styrene Butadiene Styrene (SBS) is a polymer that has proven its performance in heavy traffic, but it must be imported and expensive. Crumb rubber have high potential to be used as an asphalt modifier. Asphalt modified crumb rubber has high viscosity and is not homogeneous, so that the utilization cannot be delayed. This reduces workability in the field. This study aims to obtain asphalt modified crumb rubber which is easier to use by adding materials that do not affect its performance. RejIRE is a low viscosity additive to restore the properties of bitumen on crumb rubber modified. Experiments were carried out by adding variations in RejIRE levels to crumb rubber modified asphalt to determine its characteristics. Continued investigation of the performance of hot paved mixtures for wearing courses compared to asphalt mixtures with Pen 60/70 asphalt and SBS modified asphalt mixtures. The result is the addition of 0.75% RejIRE on asphalt crumb rubber modification have high workability. Overall the performance of the mix with SBS modified asphalt is better, but the mixture of hot paved with modified asphalt crumb rubber has a resistance to permanent deformation superior to the other paved mixtures.

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
Keyword(s):  
Dynamic Modulus ◽  
Testing Machine ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
High Modulus ◽  
Characteristic Analysis ◽  
Modified Asphalt ◽  
Universal Testing ◽  
Different Temperatures ◽  
Dynamic Modulus Test

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.

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.

Laboratory Evaluation of Mixture Type on Highly Modified Asphalt Mixtures in Virginia

2018 ◽  
Vol 2672 (28) ◽  
pp. 59-68
Author(s):  
Benjamin F. Bowers
Keyword(s):  
Asphalt Binder ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Laboratory Evaluation ◽  
Maximum Aggregate Size ◽  
Air Voids ◽  
Modified Asphalt ◽  
Modified Asphalt Binder ◽  
Dynamic Modulus Test ◽  
Scb Specimen

The work presented attempts to address reflective cracking of asphalt-surfaced pavements through binder modification with a highly polymer (HP)-modified asphalt binder. Nine asphalt mixtures ranging from fine dense-graded mixtures to stone matrix asphalt (SMA) mixtures were investigated with conventional polymer modified binders and HP binder. The dynamic modulus test, overlay test (OT), and semi-circular bend (SCB) test were used to evaluate the mixtures. In the cracking tests, HP mixtures outperformed the conventionally modified control mixtures for the same mixture type. For HP mixtures, in general, SMA mixtures performed better in the cracking test than dense-graded mixtures. One of the dense-graded mixtures having larger nominal maximum aggregate size (NMAS) performed better than the mixture with a smaller NMAS, whereas the other having a larger NMAS was not significantly different in crack testing. Further, a discussion on the calculation of bulk specific gravity and percent air voids in a cut OT and SCB specimen using saturated surface dry or vacuum sealing methods is presented.

Study on Dynamic Modulus of Waste Plastic Modified Asphalt Mixture Using Waste Plastic Bag Chips

2011 ◽  
Vol 261-263 ◽  
pp. 824-828 ◽  
Author(s):  
Qian Zhang ◽  
Shu Wei Goh ◽  
Zhan Ping You
Keyword(s):  
Phase Angle ◽  
Dynamic Modulus ◽  
Asphalt Mixture ◽  
Control Sample ◽  
Asphalt Mixtures ◽  
Test Results ◽  
Waste Plastic ◽  
Modified Asphalt ◽  
Plastic Bag ◽  
Dynamic Modulus Test

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.

scholarly journals A review of the best experience on crumb rubber – dry process modified asphalt mixture performance

2021 ◽  
Author(s):  
Ovidijus Šernas ◽  
Audrius Vaitkus ◽  
Deimantė Kilaitė
Keyword(s):  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Asphalt Mixtures ◽  
Waste Products ◽  
Dry Process ◽  
Modified Asphalt ◽  
Wet Process ◽  
Water Sensitivity ◽  
Modification Process ◽  
Dry Modification

The use of crumb rubber made from end of life tyres for asphalt mixtures modification in order to improve their properties or just utilize waste products may be considered as potential solution. Crumb rubber can be used as a bitumen modifier (wet process) or supplementary component of the asphalt mixture (dry process). Dry modification process has more potential due relatively unsophisticated technology and higher possible to use amount of crumb rubber comparing to the wet process. The performance of asphalt mixtures modified by dry process mainly depends on several factors as crumb rubber type, content and size. However, limited number of publications reported the results of dry method crumb rubber modified asphalt mixtures performance. This paper summarizes the latest findings from literature review on the modification technologies and specifications related to dry modification process, the effect of crumb rubber type and amount on modified asphalt mixture performance in terms of stiffness, rutting resistance, water sensitivity, resistance to fatigue and low temperature cracking. The algorithm of crumb rubber modified asphalt mix design was introduced.

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