Performance of Virginia’s Early Foamed Warm Mix Asphalt Mixtures

2018 ◽  
Vol 2672 (28) ◽  
pp. 178-189 ◽  
Author(s):  
Stacey D. Diefenderfer
Keyword(s):  
Dynamic Modulus ◽  
Permanent Deformation ◽  
Warm Mix Asphalt ◽  
Department Of Transportation ◽  
High Dynamic ◽  
Repeated Load ◽  
And Performance ◽  
Virginia Department ◽  
Performance Grading ◽  
Air Void

The Virginia Department of Transportation began allowing the use of warm mix asphalt (WMA) in 2008. Although several WMA technologies were investigated prior to implementation, foamed WMA was not. This study evaluated the properties and performance of foamed WMA placed during the initial implementation of the technology to determine whether the technology had performed as expected. Six mixtures produced using plant foaming technologies and placed between 2008 and 2010 were identified and subjected to field coring and laboratory testing. Coring was performed in 2014, resulting in pavement ages from 4 to 6 years. Three comparable hot mix asphalt (HMA) mixtures were cored at 5 years for comparison. Cores were evaluated for air-void contents and permeability and were subjected to dynamic modulus, repeated load permanent deformation, and overlay testing. In addition, binder was extracted and recovered for performance grading. Similar properties were found for the WMA and HMA mixtures. One WMA mixture had high dynamic modulus and binder stiffness, but overlay testing did not indicate any tendency for premature cracking. All binders had aged between two and three performance grades above that specified at construction. WMA binders and one HMA binder aged two grades higher, and the remaining two HMA binders aged three grades higher, indicating a likely influence on aging of the reduced temperatures at which the early foamed mixtures were typically produced. Overall results indicated that foamed WMA and HMA mixtures should be expected to perform similarly.

Rheological Evaluation of Asphalt Cement Derived from Alberta Oil-sand Bitumen at Different Distillation Temperatures

2020 ◽  
Author(s):  
Nura Bala ◽  
Amirhossein Ghasemirad ◽  
Leila Hashemian
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Oil Sands ◽  
Permanent Deformation ◽  
Asphalt Binders ◽  
Oil Sand ◽  
Asphalt Cement ◽  
And Performance ◽  
Oil Sands Bitumen ◽  
Performance Grading

In this study, high, intermediate and low temperature properties of two crude oil asphalts and three asphalts derived from Alberta oil sands bitumen distilled at temperatures of 400 °C, 430 °C and 460 °C were evaluated. High and intermediate temperature properties of the asphalt binders at different distillation temperatures were studied using a dynamic shear rheometer (DSR) through the performance grading (PG) tests. Low-temperature properties and performance grading were evaluated using a bending beam rheometer (BBR). The DSR high-temperature analysis indicated that oil sand bitumens distilled at high temperatures have significantly higher stiffness and more resistant to permanent deformation. BBR test results showed that irrespective of the asphalt source, oil sand bitumens distilled at lower temperatures are more resistant to cracking at low temperatures. The overall results indicate that oil sand bitumens are thus suitable to be used for both asphalt pavements requiring low and high-temperature resistance.

Permeability Specifications for High-Performance Concrete Decks

1998 ◽  
Vol 1610 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Celik Ozyildirim
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Field Application ◽  
Low Permeability ◽  
Department Of Transportation ◽  
Freezing And Thawing ◽  
Void System ◽  
Virginia Department ◽  
Air Void

Durable concrete exposed to the environment requires a proper air-void system for protection against cycles of freezing and thawing. Durable concretes also must have low permeability to resist the infiltration of harmful solutions into concrete. Work was conducted by the Virginia Department of Transportation (VDOT) on the permeability of concretes. Information is provided on permeability, recent VDOT efforts with a low-permeability specification, and the field application of the low-permeability specification.

scholarly journals Flexible Pavement Recycling Techniques: A Summary of Activities

2021 ◽  
Author(s):  
Marshall Thompson ◽  
◽  
Ramez Hajj ◽  
Keyword(s):  
Department Of Transportation ◽  
Asphalt Emulsion ◽  
Pavement Condition ◽  
Testing Procedures ◽  
Full Depth Reclamation ◽  
Foamed Asphalt ◽  
And Performance ◽  
Virginia Department ◽  
Falling Weight ◽  
Special Provision

Cold in-place recycling (CIR) involves the recycling of the asphalt portions (including hot-mix asphalt and chip, slurry, and cape seals, as well as others) of a flexible or composite pavement with asphalt emulsion or foamed asphalt as the binding agent. Full-depth reclamation (FDR) includes the recycling of the entire depth of the pavement and, in some cases, a portion of the subgrade with asphalt, cement, or lime products as binding agents. Both processes are extensively utilized in Illinois. This project reviewed CIR and FDR projects identified by the Illinois Department of Transportation (IDOT) from the Transportation Bulletin and provided comments on pavement designs and special provisions. The researchers evaluated the performance of existing CIR/FDR projects through pavement condition surveys and analysis of falling weight deflectometer data collected by IDOT. They also reviewed CIR/FDR literature and updated/modified (as appropriate) previously provided inputs concerning mix design, testing procedures, thickness design, construction, and performance as well as cold central plant recycling (CCPR) literature related to design and construction. The team monitored the performance of test sections at the National Center for Asphalt Technology and Virginia Department of Transportation. The researchers assisted IDOT in the development of a CCPR special provision as well as responded to IDOT inquiries and questions concerning issues related to CIR, FDR, and CCPR. They attended meetings of IDOT’s FDR with the Cement Working Group and provided input in the development of a special provision for FDR with cement. The project’s activities confirmed that CIR, FDR, and CCPR techniques are successfully utilized in Illinois. Recommendations for improving the above-discussed techniques are provided.

Comparison of flow number, dynamic modulus, and repeated load tests for evaluation of HMA permanent deformation

2013 ◽  
Vol 44 ◽  
pp. 391-398 ◽  
Author(s):  
Jun Zhang ◽  
Allex E. Alvarez ◽  
Sang Ick Lee ◽  
Angela Torres ◽  
Lubinda F. Walubita
Keyword(s):  
Dynamic Modulus ◽  
Permanent Deformation ◽  
Flow Number ◽  
Load Tests ◽  
Repeated Load

Preliminary Field Validation of Simple Performance Tests for Permanent Deformation: Case Study

2003 ◽  
Vol 1832 (1) ◽  
pp. 209-216 ◽  
Author(s):  
Fujie Zhou ◽  
Tom Scullion
Keyword(s):  
Dynamic Modulus ◽  
Permanent Deformation ◽  
Mixture Design ◽  
Asphalt Mixtures ◽  
Load Test ◽  
Performance Tests ◽  
Field Validation ◽  
Dynamic Modulus Test ◽  
Repeated Load

Simple performance tests (SPTs) to be used with the Superpave® volumetric mixture design procedure were recently recommended by NCHRP Project 9-19 (Simple Performance Test for Superpave Mix Design). Field validation of the SPTs is critical to their final acceptance and implementation in Superpave mixture design practice. Special Pavement Studies-1 (SPS-1) prematurely rutted sections on US-281 in Texas were used to validate the SPTs for permanent deformation, including the dynamic modulus test and repeated-load test and associated rutting indicators E*/sin δ and flow number ( F n), respectively. The results of this case study clearly show that both the dynamic modulus test and E*/sin δ and the repeated-load test and F n can effectively distinguish the good mixtures from the bad. Compared with E*/sin δ, F n can better differentiate the performance of asphalt mixtures. These results preliminarily validated both SPTs for permanent deformation. In addition, the location of the tertiary point in the plot of permanent strain versus number of load repetitions is clarified; a simple linear model needs to be added in order to determine the F n. Furthermore, the possibility of using the number of load repetitions ( Nps) corresponding to the initial point of the secondary stage to characterize the rutting resistance of asphalt mixtures is discussed. The new indicator proposed is supported by the limited data presented in this paper and can be easily determined and can reduce test duration significantly.

Permanent Deformation of Steel under Slowly Repeated Load

1954 ◽  
Vol 3 (15) ◽  
pp. 314-317
Author(s):  
Minoru KAWAMOTO ◽  
Tadakazu SAKURAI ◽  
Morio SEKI
Keyword(s):  
Permanent Deformation ◽  
Repeated Load

Effect of aggregate gradation on permanent deformation behavior of a warm mix asphalt

2016 ◽  
Vol 58 (7-8) ◽  
pp. 678-688 ◽  
Author(s):  
Ebrahim Sangsefidi ◽  
Ali Mansourkhaki ◽  
Hasan Ziari
Keyword(s):  
Deformation Behavior ◽  
Permanent Deformation ◽  
Warm Mix Asphalt ◽  
Aggregate Gradation

Effects of Asphalt Foaming on Damage Characteristics of Foamed Warm Mix Asphalt

2021 ◽  
pp. 036119812199782
Author(s):  
Biswajit K. Bairgi ◽  
Md Amanul Hasan ◽  
Rafiqul A. Tarefder
Keyword(s):  
Permanent Deformation ◽  
Warm Mix Asphalt ◽  
Creep Recovery ◽  
Deformation Model ◽  
Contact Method ◽  
Moisture Susceptibility ◽  
Viscoelastic Continuum Damage ◽  
Foamed Asphalt ◽  
Flexural Beam ◽  
Wheel Tracking

In the asphalt foaming process, the foaming water content (FWC) controls the formation and characteristics of water bubbles. These water bubbles are expected to be expelled from the foamed warm mix asphalt (WMA) during mixing and compaction. However, foaming water may not be completely expelled, rather some of the microbubbles may be trapped in the foamed WMA even after compaction. These microbubbles, or undissipated water, can diffuse over time and cause damage to the foamed WMA. To this end, this study has determined the effects of foaming on the fatigue, moisture damage, and permanent deformation characteristics of foamed WMA. Foamed asphalt and mixtures were designed with varying FWCs and they were tested using linear amplitude sweep, multiple stress creep recovery, four-point flexural beam, and Hamburg wheel tracking tests. Primarily, asphalt foaming dynamics were assessed with a laser-based non-contact method. A simplified viscoelastic continuum damage concept and a three-phase permanent deformation model were used for damage evaluation. The study reveals that foaming softens the binder, which results in slightly higher rutting and moisture susceptibility, though an equivalent or slightly improved fatigue characteristic compared with the regular hot mix asphalt.

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