Evaluation of Materials From Northeast Texas Using Superpave Mix Design Technology

1997 ◽  
Vol 1583 (1) ◽  
pp. 98-105 ◽  
Author(s):  
Robert B. McGennis
Keyword(s):  
Task Force ◽  
Moisture Damage ◽  
Mix Design ◽  
Department Of Transportation ◽  
Moisture Sensitivity ◽  
Moisture Susceptibility ◽  
Asphalt Overlay ◽  
South Central ◽  
Sensitivity Evaluation ◽  
Texas Department

During 1994 and 1995, asphalt overlay performance problems in the form of disintegration, rutting, and raveling were experienced in the Atlanta District of the Texas Department of Transportation (TxDOT). An investigation of the damage by TxDOT engineers in Atlanta identified the cause as extreme moisture susceptibility of asphalt mixtures containing locally available crushed gravel. A task force was assembled to identify tests and specifications to allow use of local gravel aggregates while, at the same time, precluding future moisture damage problems. The resources of the South Central Superpave Center were mobilized to assess whether Superpave mix design tests and criteria would have identified the mixtures as troublesome in ways other than moisture sensitivity. Because TxDOT already uses a moisture damage test very similar to the Superpave moisture sensitivity evaluation, no Superpave moisture damage tests were conducted. The Superpave mix design evaluation indicated that one or more Superpave aggregate tests, gradation requirements, and volumetric and compaction properties would have precluded use of the materials.

Case Study of Overlay Performance on Rigid Pavement in Bowie County, Texas

1996 ◽  
Vol 1525 (1) ◽  
pp. 107-114 ◽  
Author(s):  
B. Frank Mccullough ◽  
Terry Dossey ◽  
Yoon-Ho Cho
Keyword(s):  
Ride Quality ◽  
Department Of Transportation ◽  
Rigid Pavement ◽  
Asphalt Overlay ◽  
Texas Department ◽  
Before And After ◽  
Design Division ◽  
Roughness Measurements

A case study of flexible overlay performance on an old rigid pavement is presented. This special study was devised in cooperation with the Pavement Section of the Design Division of the Texas Department of Transportation to take advantage of a unique opportunity to study overlay effectiveness. Condition survey, roughness measurements, and deflection basins were taken before and after the removal of an old flexible overlay and after the construction of a new asphalt overlay. Subsequent analysis of the data shows that although the overlay restores the ride quality of a rigid pavement and eliminates dynamic loading caused by swelling subgrades, it can only slow, not reverse, fatigue in the underlying pavement structure.

scholarly journals Titus Phase Archeology at the S. Stockade Site (41TT865) on Tankersley Creek, Titus County, Texas

2003 ◽  
Author(s):  
Timothy K. Perttula ◽  
Bo Nelson ◽  
LeeAnna Schniebs
Keyword(s):  
Department Of Transportation ◽  
The West ◽  
Standing Water ◽  
Texas Department ◽  
Small Rise ◽  
Dense Concentration

The S. Stockade site was discovered on a small rise (330 feet amsl) in the Tankersley Creek floodplain during a recent archeological survey for the Texas Department of Transportation. Tankersley Creek is a southward-flowing tributary to Big Cypress Creek, and enters that creek’s floodplain a few miles below the Lake Bob Sandlin dam. There is a dense concentration of prehistoric archeological sites throughout the Tankersley Creek valley, particularly post-A.D. 800 Caddo Indian sites. This paper discusses the archeology of the S. Stockade site, a Late Caddoan Titus phase settlement. The rise at the S. Stockade site is grass-covered (with a surface visibility of less than 10%), except along the eroded slopes, where the clay B-horizon subsoil is exposed. The old creek channel immediately to the west of the rise has recently been channelized, and between the rise and the channelized creek are several low-lying marshy areas with standing water.

The Superpave Gradation Restricted Zone and Performance Testing With the Georgia Loaded Wheel Tester

1997 ◽  
Vol 1583 (1) ◽  
pp. 106-111 ◽  
Author(s):  
Donald E. Watson ◽  
Andrew Johnson ◽  
David Jared
Keyword(s):  
High Performance ◽  
Performance Testing ◽  
Mix Design ◽  
Design System ◽  
Department Of Transportation ◽  
Natural Sand ◽  
Aggregate Gradation ◽  
Actual Field ◽  
And Performance ◽  
Highway Research

Guidelines for the new hot-mix asphalt design system, Superpave, were developed under the Strategic Highway Research Program. One of the most controversial components of this system is the aggregate gradation restricted zone. This restricted zone was adopted as a gradation specification primarily to deter the use of high levels of natural sand in high-performance mixes. By designing mixes with gradations that avoid the restricted zone (i.e., limit natural sand), the internal strength provided by internal friction could be improved. Some agencies question the validity of the restricted zone. The specified gradations of many current mixes contain bands that enter the restricted zone, but the mixes have performed well for years in actual field conditions. The Georgia Department of Transportation (GDOT) currently specifies several standard mixes with gradations that enter the restricted zone and still perform well. These high-performance mixes contain good quality, 100 percent manufactured aggregates and no natural sand. GDOT recommends that the Georgia loaded wheel tester or some other proof tester be incorporated into the mix design process to screen mixes before rejecting them solely because their combined gradation enters the restricted zone. If mixes having combined gradations that enter the restricted zone are categorically rejected, mixes that are economical for the purpose intended may be rejected in the process.

Comparison of the moisture damage of bituminous binder coupled with glass and limestone substrate using pull-off test

2019 ◽  
Vol 46 (3) ◽  
pp. 188-194 ◽  
Author(s):  
Éric Lachance-Tremblay ◽  
Michel Vaillancourt ◽  
Daniel Perraton ◽  
Hervé Di Benedetto
Keyword(s):  
Tensile Testing ◽  
Moisture Damage ◽  
Hot Water ◽  
Test Results ◽  
Substrate Type ◽  
Testing Instrument ◽  
Moisture Susceptibility ◽  
Water Conditioning ◽  
Binder Type ◽  
Bituminous Binders

In this paper, the moisture susceptibility of different bituminous binders with two substrates (glass and limestone) was investigated. To that end, the tensile strength of different combinations of bituminous binder–substrate bond was measured using a pull-off test. This test was adapted from the pneumatic adhesion tensile testing instrument (PATTI) test to improve repeatability. Samples were tested in dry condition and after a 7-day conditioning in hot water bath (60 °C). An analysis of variance (ANOVA) was performed on the test results. Overall, the results show that in dry condition, the pull-off strength is a function of the bituminous binder type rather than of the substrate type. After water conditioning, an increase in the pull-off strength was observed for the bituminous binder without polymers and coupled with glass substrate. This was associated with an increase in binder stiffness. For the limestone substrate, the effect of water conditioning was significant only for one type of binder.

Effectiveness of Loaded Wheel Tracking Test to Ascertain Moisture Susceptibility of Asphalt Mixtures

2021 ◽  
pp. 036119812110363
Author(s):  
Moses Akentuna ◽  
Louay N. Mohammad ◽  
Sanchit Sachdeva ◽  
Samuel B. Cooper ◽  
Samuel B. Cooper
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Moisture Damage ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Creep Recovery ◽  
Moisture Susceptibility ◽  
Freeze Thaw ◽  
Wheel Tracking ◽  
Mixture Samples

Moisture damage of asphalt mixtures is a major distress affecting the durability of asphalt pavements. The loaded wheel tracking (LWT) test is gaining popularity in determining moisture damage because of its ability to relate laboratory performance to field performance. However, the accuracy of LWT’s “pass/fail” criteria for screening mixtures is limited. The objective of this study was to evaluate the capability of the LWT test to identify moisture susceptibility of asphalt mixtures with different moisture conditioning protocols. Seven 12.5 mm asphalt mixtures with two asphalt binder types (unmodified PG 67-22 and modified PG 70-22), and three aggregate types (limestone, crushed gravel, and a semi-crushed gravel) were utilized. Asphalt binder and mixture samples were subjected to five conditioning levels, namely, a control; single freeze–thaw-; triple freeze–thaw-; MiST 3500 cycles; and MiST 7000 cycles. Frequency sweep at multiple temperatures and frequencies, and multiple stress creep recovery tests were performed to evaluate asphalt binders. LWT test was used to evaluate the asphalt mixture samples. Freeze–thaw and MiST conditioning resulted in an increase in stiffness in the asphalt binders as compared with the control. Further, freeze–thaw and MiST conditioning resulted in an increase in rut depth compared with the control asphalt mixture. The conditioning protocols evaluated were effective in exposing moisture-sensitive mixtures, which initially showed compliance with Louisiana asphalt mixture design specifications.

Data Mining Statewide Department of Transportation Volumetrically Designed Asphalt Mixture Records

2021 ◽  
pp. 036119812110613
Author(s):  
Ben C. Cox ◽  
Jonathan Easterling ◽  
W. Griffin Sullivan ◽  
Alex Middleton ◽  
Isaac L. Howard
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Mechanical Tests ◽  
Unintended Consequences ◽  
Mix Design ◽  
Department Of Transportation ◽  
Database Analysis ◽  
Societal Pressure ◽  
Asphalt Content ◽  
Asphalt Paving

In recent years, the asphalt paving industry has been strained by numerous factors including increased asphalt binder costs, funding that has not kept up with material costs, increased societal pressure to recycle, and deteriorating pavement networks. Mix design should account for the market in which it is used, which is very different now than when today’s volumetric mix design practices were developed (many of the aforementioned factors were less present). Given this reality, a statewide database of all 1,452 approved mix designs in Mississippi from 2005 to 2018 was compiled and analyzed, and the objective of this paper is to present findings, trends, and unintended consequences of exclusive reliance on volumetrics. With volumetrics-only mix design, asphalt content is primarily controlled by voids in mineral aggregate (VMA), which is influenced by aggregate bulk specific gravity (Gsb). Minor Gsb deviations (i.e., within AASHTO d2 s limits), can significantly affect VMA, so much so that 99% of Mississippi’s mixes could be failing VMA while reported VMA passes. This allows mix manipulation and economization, with 0.8% asphalt content reductions possible while still meeting volumetric requirements. Recycled materials can exacerbate this issue, and common approaches to increase asphalt content (decreasing design gyration level or using finer gradations) are ineffective with fixed VMA requirements. Overall, the mix design database analysis agrees with numerous smaller studies but does so with an entire state’s actual practice. This presents a compelling case that volumetrics-only mix design has limitations, and supports ongoing efforts to reintegrate mechanical tests.

Twenty-Five Years of Pavement Smoothness Specifications in Georgia

1996 ◽  
Vol 1545 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Ronald Collins ◽  
Wouter Gulden ◽  
Dan R. Brown
Keyword(s):  
South Dakota ◽  
Mix Design ◽  
Response Type ◽  
Department Of Transportation ◽  
The Public ◽  
Measurement Systems ◽  
Construction Specifications ◽  
Pavement Construction

The traveling public generally recognizes the smoothness of a pavement as a major indicator of quality. A newly constructed pavement can have excellent materials, mix design, compaction, and so forth, but if the public considers the ride rough, the quality is considered poor. While continually striving to improve the quality of paving materials in mix designs, the Georgia Department of Transportation (GDOT) began an effort in 1968 to attain the ability to accurately measure the smoothness of a pavement so that this indicator of quality could be measured and specified during construction. GDOT has been using response-type smoothness-measurement systems in its construction specifications for acceptance of projects since 1972 and since 1979 for both rejection and acceptance. The evolution of the pavement smoothness-measuring program in Georgia, the program operating procedures, and the current smoothness specifications are described. The long-term benefits of smoothness specification for pavement construction are also discussed, as is GDOT's effort to replace the Mays Meter trailer systems currently used with South Dakota–type, laser-based road profilers.

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