Effect of rejuvenator types and mixing procedures on volumetric properties of asphalt mixtures with 50% RAP

2019 ◽  
Vol 218 ◽  
pp. 457-464 ◽  
Author(s):  
Zhaoxing Xie ◽  
Hashim Rizvi ◽  
Caitlin Purdy ◽  
Ayman Ali ◽  
Yusuf Mehta
Keyword(s):  
Asphalt Mixtures ◽  
Volumetric Properties

Mechanistic and Volumetric Properties of Asphalt Mixtures with Recycled Asphalt Pavement

2005 ◽  
Vol 1929 (1) ◽  
pp. 28-36 ◽  
Author(s):  
Jo Sias Daniel ◽  
Aaron Lachance
Keyword(s):  
Dynamic Modulus ◽  
Creep Compliance ◽  
Asphalt Pavement ◽  
Superposition Principle ◽  
Asphalt Mixtures ◽  
Volumetric Properties ◽  
Recycled Asphalt Pavement ◽  
Recycled Asphalt ◽  
Creep Flow ◽  
Tension And Compression

This research examines how the addition of recycled asphalt pavement (RAP) changes the volumetric and mechanistic properties of asphalt mixtures. A Superpave® 19-mm mixture containing 0% RAP was the control for evaluating properties of mixes containing 15%, 25%, and 40% RAP. Two types of RAP were evaluated: a processed RAP and an unprocessed RAP (grindings). Testing included dynamic modulus in tension and compression, creep compliance in compression, and creep flow in compression. Dynamic modulus and creep compliance master curves were constructed with the use of the time–temperature superposition principle to describe the behavior of each mix over a range of temperatures. The voids in mineral aggregate (VMA) and voids filled with asphalt (VFA) of the RAP mixtures increased at the 25% and 40% levels, and there was also an influence of preheating time on the volumetric properties. The dynamic modulus of the processed RAP mixtures increased from the control to 15% RAP level, but the 25% and 40% RAP mixtures had dynamic modulus curves similar to that of the control mixture in both tension and compression. The creep compliance curves showed similar trends. A combination of gradation, asphalt content, and volumetric properties is likely the cause of these trends.

Impact of Gyration Reduction and Design Specification Changes on Volumetric Properties of Virginia Dense-Graded Asphalt Mixtures

2018 ◽  
Vol 2672 (28) ◽  
pp. 143-153 ◽  
Author(s):  
Stacey D. Diefenderfer ◽  
Benjamin F. Bowers ◽  
Kevin K. McGhee
Keyword(s):  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Design Parameters ◽  
Maximum Aggregate Size ◽  
Volumetric Properties ◽  
Air Voids ◽  
Asphalt Mix ◽  
Production Value ◽  
Virginia Department ◽  
Air Void

In 2015, the Virginia Department of Transportation (VDOT) proposed changes to their specification for asphalt mix design. The changes incorporated a reduction of design gyrations from 65 to 50; the addition of constraints on the No. 4 (4.75 mm) and No. 30 (600 µm) sieves; and adjustments to the production value for voids filled with asphalt and minimum voids in mineral aggregate. Before these modifications were fully adopted, a study was performed to assess the effect of the changes on mixture properties and laboratory performance. Eleven pairs of asphalt mixtures were evaluated; the pairs consisted of a typical VDOT 65-gyration mixture produced under the specification current at the time and a companion 50-gyration mixture designed and produced in accordance with the proposed specification. Mixtures were evaluated to determine the effect of the design parameters on volumetric properties, gradation, and permeability. The changes had very little effect on volumetric properties or gradation. Permeability effects were mixed, with 9.5 mm nominal maximum aggregate size mixtures requiring greater compaction to meet permeability requirements and 12.5 mm nominal maximum aggregate size mixtures showing improved permeability even at higher air-void contents. For the 50-gyration mixtures, core air voids were reduced, indicating the potential for increased durability attributable to improved densification in the field.

Evaluation Of Volumetric Properties And Resilient Modulus Performance Of Nanopolyacrylate Polymer Modified Binder (NPMB) Asphalt Mixes

2015 ◽  
Vol 73 (4) ◽  
Author(s):  
Ekarizan Shaffie ◽  
Juraidah Ahmad ◽  
Ahmad Kamil Arshad ◽  
Dzraini Kamarun
Keyword(s):  
Resilient Modulus ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Volumetric Properties ◽  
Modified Bitumen ◽  
Asphalt Mixes ◽  
Different Types ◽  
Potential Benefits ◽  
Modified Binder ◽  
Polymer Modified Bitumen

This paper presents the potential benefits of nanopolyacrylate (NPA) for the asphalt mixtures used on pavement. This research evaluates the resilient modulus performance of dense graded Superpave-designed HMA mix. Two different types of dense graded Superpave HMA mix were developed consists of unmodified bitumen mix (UMB) and nanopolyacrylate modified bitumen mix (NPMB). Nanopolyacrylate polymer modified bitumen was prepared from addition of 6 percent of NPA polymer into asphalt bitumen. Resilient modulus results from Resilient Modulus test were determined to evaluate the performance of these mixtures. Results showed that all the mixes passed the Superpave volumetric properties criteria which indicated that these mixtures were good with respect to durability and flexibility. The Resilient modulus result of NPMB demonstrates better resistance to rutting than those prepared using UMB mix. It was estimated that the average resilient modulus values for both UMB and NPMB mixtures are decreased by 80 percent when the test temperature increased from 25ºC to 40ºC.   In conclusion, the addition of NPA to the binder has certainly improved the bitumen properties significantly and hence increase the resistant to rutting of the asphalt mixture.

Rutting Performance of Hot Mix Asphalt Mixture Using Nanopolyacrylate Polymer Modifier

2015 ◽  
Vol 752-753 ◽  
pp. 194-198 ◽  
Author(s):  
E. Shaffie ◽  
J. Ahmad ◽  
D. Kamarun
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Volumetric Properties ◽  
Road Pavement ◽  
Significant Difference ◽  
Different Types ◽  
Polymer Modifier ◽  
Test Result ◽  
Bitumen Modification

Rutting is a common pavement failure in road pavement. Rutting occurs mainly due to several factors including increasing of vehicles numbers, environmental conditions and also due to construction and design errors. As a consequence the service life of asphalt pavement is affected and will be decreased. Various researches reported that using different types of polymers in bitumen modification could be a solution to delay deterioration of asphalt pavement. The main purpose of the study was to investigate the effect of the NPA polymer modifier on the rutting behaviour of the asphalt mixtures through Superpave designed mixtures. . Two different types of dense graded Superpave HMA mix were developed consists of Control mix and nanopolyacrylate (NPA) mix. Results showed that all the mixes passed the Superpave volumetric properties criteria which indicate that these mixtures were good with respect to durability and flexibility. Furthermore there is a significant difference between Control mix and NPA mix in terms of rutting in which rut depth after 8000 passes for Control mix was 5.94 mm while for NPA mix was 2.98 mm. The results of this investigation indicated that the Rutting test result of NPA demonstrates 3% better resistance to rutting than those prepared using Control mix. This is due to the addition of NPA to the bitumen has certainly improved the bitumen properties significantly and hence increase the resistant to rutting of the asphalt mixture. Therefore, it can be concluded that NPA polymer is feasible to be used as asphalt modifier and has potential for improvement in the field of pavement material and construction in future.

scholarly journals Shape Characterizing of Aggregates Produced through Different Crushing Techniques

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1199
Author(s):  
Ghulam Yaseen ◽  
Wesam Salah Alaloul ◽  
Imran Hafeez ◽  
Abdul Hannan Qureshi
Keyword(s):  
Form Factor ◽  
Aspect Ratio ◽  
Shape Factor ◽  
Asphalt Mixtures ◽  
Volumetric Properties ◽  
Shape Parameters ◽  
Jaw Crusher ◽  
Factor Form ◽  
Marshall Stability ◽  
Aggregate Shape

The aggregate shape properties produced from the different crushing techniques influence the performance properties of the asphalt mixtures. The objective of this study was to classify the aggregates into spherical, flat, elongated and flat, and elongated shapes, collected from impact crusher and jaw crusher of two sources, and to calculate the shape parameters, such as aspect ratio, shape factor, form factor, sphericity, roundness, and angularity index. In addition, this study also investigated the effects of this classification on the Marshall stability and volumetric properties of asphalt mixtures prepared from the respective shape of aggregates. The results showed that the aggregate of different fractions (passing 37.5 mm and retained on 4.75 mm) produced from the jaw crusher of Margalla quarry showed better shape parameters. The spherical aggregates collected from all crushers showed 20–30% higher Marshall stability of the blends by improving the mechanical and volumetric properties of the asphalt mixtures.

Evaluation of Permeability of Superpav® Asphalt Mixtures

2003 ◽  
Vol 1832 (1) ◽  
pp. 50-58 ◽  
Author(s):  
Louay N. Mohammad ◽  
Ananda Herath ◽  
Baoshan Huang
Keyword(s):  
Heavy Traffic ◽  
Model Development ◽  
Asphalt Mixtures ◽  
Volumetric Properties ◽  
Void Content ◽  
Permeability Test ◽  
Statistical Regression ◽  
Data Set ◽  
Pavement Structures ◽  
Transportation Research

The presence of water in a pavement system is detrimental to its life. Permeable asphalt concrete pavement structures are vulnerable to stripping, which causes premature damage under heavy traffic. To assess the permeability of asphalt mixtures, a research study was conducted at the Louisiana Transportation Research Center (LTRC). Laboratory permeability tests were performed on field cores taken from 17 Superpave® projects in Louisiana. An LTRC-modified version of Karol-Warner's falling-head permeameter was used to conduct the permeability test. A sensitivity analysis was performed to relate the permeability test results to mixture volumetric properties such as air void content, compaction effort, mixture gradation, and lift thickness. A statistical regression model was developed to predict the permeability of Superpave mixtures from the mixture volumetric properties. The model successfully predicted the coefficient of permeability of asphalt mixtures from a separate data set that was not included in the model development.

Effects of Reheating Procedure and Oven Type on Performance Testing Results of Asphalt Mixtures

2018 ◽  
Vol 2672 (26) ◽  
pp. 124-133 ◽  
Author(s):  
Zachary Lemke ◽  
Husam Sadek ◽  
Daniel Swiertz ◽  
Signe Reichelt ◽  
Hussain U. Bahia
Keyword(s):  
Performance Testing ◽  
Substantial Effect ◽  
Asphalt Mixtures ◽  
Volumetric Properties ◽  
Performance Tests ◽  
Laboratory Equipment ◽  
Standard Procedures ◽  
And Performance ◽  
Time Required ◽  
Wheel Tracking

Reheating and oven-aging procedures of plant-produced asphalt mixtures in laboratories are important topics to consider as performance testing of mixtures becomes more popular among agencies. Differences between laboratory equipment and procedure could significantly affect performance properties. The objective of this study is to investigate the influence of sample size, oven type, and variation in reheating/aging temperatures on the results of two performance tests on plant-produced mixtures. A selected mixture was tested for volumetric properties and performance using Hamburg wheel-tracking (HWT) and semi-circular bending (SCB-IFIT) tests. Results show that reheating mixtures uncovered and in smaller containers could significantly reduce the time to achieve aging temperature, and could make the process more efficient and consistent. In addition, aging using three different oven types showed that temperature within ovens can vary significantly depending on the location of the sample inside the oven, which affects the time required to reach the target temperature, and thus may also influence the aging of the sample. The mixture volumetric properties show that the effect of various heating conditions is marginal. Using the developed reheating/aging procedure of this study, the results of the HWT and SCB-IFIT tests showed no substantial effect of oven type on rutting and cracking resistance. The overall results indicate that there is a need to standardize the conditions of reheating, sample geometry, and to verify uniformity of temperature in ovens. Such standardization can further reduce variability and thus should be part of the AASHTO/ASTM standard procedures for quality control, or of laboratory equipment calibration procedures.

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