Performance Analysis of Ultrathin Whitetopping Intersections on US-169: Elk River, Minnesota

2003 ◽  
Vol 1823 (1) ◽  
pp. 18-27 ◽  
Author(s):  
Julie M. Vandenbossche
Keyword(s):  
Test Section ◽  
Hot Mix Asphalt ◽  
Asphalt Pavements ◽  
Department Of Transportation ◽  
Uniform Thickness ◽  
Research Facility ◽  
Transverse Cracks ◽  
Elk River ◽  
Joint Pattern

The Minnesota Department of Transportation constructed an ultrathin whitetopping (UTW) project at three consecutive intersections on US-169 at Elk River, Minnesota, to gain more experience with both the design and the performance of UTW. Distinct cracking patterns developed within each test section. The UTW test sections with a 1.2- ×1.2-m (4- ×4-ft) joint pattern included corner breaks and transverse cracks. Corner breaks were the primary distress in the test section with a 1.8- ×1.8-m (6- ×6-ft) joint pattern, although very little cracking was exhibited. The Minnesota Road Research Facility UTW test sections on I-94 allow comparisons of the same UTW design on hot-mix asphalt (HMA) pavements with different structural capacities to be made. The strain and deflection measurements emphasize the importance of the support provided by the HMA layer. A reduction in this support occurs when the temperature of the HMA is increased or when the HMA begins to ravel. During evaluations of whether UTW is a viable rehabilitation alternative, cores should be pulled from the pavement to determine if the asphalt is stripping and if the asphalt layer has adequate thickness. UTW can be successfully placed on as little as 76 mm (3 in.) of asphalt, if the quality of the asphalt is good. The cores should also reveal whether the asphalt layer is of uniform thickness and whether stripping and raveling have occurred. If the asphalt layer is of uniform thickness and stripping and raveling have not occurred, UTW is a good option for use in the rehabilitation of asphalt pavements.

Georgia’s Experience With Crumb Rubber in Hot-Mix Asphalt

1997 ◽  
Vol 1583 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Dan R. Brown ◽  
David Jared ◽  
Chris Jones ◽  
Don Watson
Keyword(s):  
Test Section ◽  
Hot Mix Asphalt ◽  
Crumb Rubber ◽  
Vacuum Extraction ◽  
Department Of Transportation ◽  
Reflective Cracking ◽  
Ground Tire Rubber ◽  
Asphalt Cement ◽  
Wet Process ◽  
Henry County

In 1991, the Georgia Department of Transportation (GDOT) began to evaluate the production and placement of crumb rubber hot-mix asphalt. The crumb rubber mix (CRM) used by GDOT was produced by adding ground tire rubber to hot-mix asphalt using the wet process. A test section of CRM was placed on I-75 in Henry County, just south of Atlanta, consisting of a surface mix containing 6 percent crumb rubber by weight of asphalt cement (AC). The test section was evaluated from 1991 to 1995. The test section indicated that the CRM became very brittle over time, as indicated by a large increase in viscosity and decrease in penetration, and by a large amount of transverse reflective cracking. Compared with the control mix, the CRM did not reduce rutting and was more than twice as expensive to place. In addition to the test section, two contract projects were initiated using CRM. These two projects indicated that CRM could be produced and placed using conventional equipment requiring only a few modifications. On-site blending units were used to combine the crumb rubber at a dosage rate of 16 percent by weight of AC. Pump and metering equipment was modified to accurately meter the stiff asphalt material, and correction factors were established for determining the AC content by vacuum extraction, since some of the rubber particles were retained in the aggregate portion of the sample.

Hot In-Place Recycling of Asphalt Pavements: Oregon Experience

1996 ◽  
Vol 1545 (1) ◽  
pp. 113-119 ◽  
Author(s):  
David F. Rogge ◽  
Walter P. Hislop ◽  
Richard L. Dominick
Keyword(s):  
Design Procedure ◽  
Project Selection ◽  
Lessons Learned ◽  
Mix Design ◽  
Asphalt Pavements ◽  
Ride Quality ◽  
Department Of Transportation ◽  
Suitable Candidate

A study was carried out to evaluate the potential of using hot in-place recycling (HIR) as a rehabilitation alternative in Oregon. Data from six Oregon Department of Transportation HIR projects constructed in 1992–1993 were analyzed. The construction equipment, pavement properties, project selection, mix design, and resulting performance are summarized and presented. Only one HIR project was successful in rejuvenating the pavement and restoring ride quality. Of particular interest are the problems encountered in the other projects, which are discussed and show the importance of preliminary engineering and project selection for successful HIR. The lessons learned from the six projects are used as guidelines for selecting suitable candidate pavements for HIR. The results from the HIR projects combined with a literature review and limited laboratory testing led to a recommended HIR mix design procedure. Significant findings include the following: (a) HIR is a developing technology that shows promise for properly selected projects, (b) project selection is the most critical step in the HIR process, and (c) critical mix design inputs come from testing in situ pavement properties and laboratory specimens remolded with rejuvenating agent added.

Effectiveness of Lime in Hot-Mix Asphalt Pavements

2003 ◽  
Vol 1832 (1) ◽  
pp. 34-41 ◽  
Author(s):  
Peter E. Sebaaly ◽  
Edgard Hitti ◽  
Dean Weitzel
Keyword(s):  
Hot Mix Asphalt ◽  
Moisture Damage ◽  
Performance Data ◽  
Asphalt Pavements ◽  
Pavement Performance ◽  
Department Of Transportation ◽  
Lime Treatment ◽  
Field Samples ◽  
Maintenance And Rehabilitation ◽  
The Impact

The pavement community has recognized that moisture damage of hot-mix asphalt (HMA) has been a serious problem since the early 1960s. Numerous additives have been evaluated with the objective of reducing the potential of moisture damage in HMA mixtures; lime has been one of the most common ones. The Nevada Department of Transportation has been using lime in HMA mixtures since the mid-1980s. The objective of this research was to quantify the improvements in pavement performance that have been realized through the addition of lime to HMA mixtures. The program evaluated field samples and pavement performance data from untreated and lime-treated pavements. The properties of untreated and lime-treated mixtures from field projects in the southern and northwestern parts of Nevada indicate that lime treatment of Nevada's aggregates significantly improves the moisture resistance of HMA mixtures. The study showed that lime-treated HMA mixtures become significantly more resistant to multiple freeze–thaw cycles than do the untreated mixtures. Long-term pavement performance data indicate that under similar environmental and traffic conditions, the lime-treated mixtures provide better-performing pavements with fewer requirements for maintenance and rehabilitation activities. The analysis of the impact of lime on pavement life indicates that lime treatment extends the performance life of HMA pavements by an average of 3 years. This extension represents an average increase of 38% in the expected pavement life.

Initial Ride Quality of Hot-Mix Asphalt Pavements

2005 ◽  
Vol 1907 (1) ◽  
pp. 104-112
Author(s):  
M. Stroup-Gardiner ◽  
Alan Carter ◽  
Thomas Das ◽  
Brian Bowman
Keyword(s):  
Hot Mix Asphalt ◽  
Asphalt Pavements ◽  
Ride Quality ◽  
Acceptance Testing ◽  
International Roughness Index ◽  
Wide Range ◽  
Key Issues ◽  
Lane County ◽  
Local Anomalies

Ride quality assessed with an inertial profiler on flexible pavement was used to provide initial information on the following key issues: repeatability associated with international roughness index (IRI) values for a wide range of hot-mix asphalt (HMA) material variables, timing of acceptance testing for initial ride quality, IRI changes with type of roadway, influence of stops and starts in the paving operation on ride quality, identification of “bump,” and effect of grinding on IRI. IRI was calculated for 25-ft intervals instead of the standard 0.1 mi (528 ft) for all testing to highlight local anomalies such as bumps due to paving stoppages. Results indicate that the standard deviation of three replicate passes with an inertial profiler is 5 in./mi (includes 46 HMA mixes on the Auburn University National Center for Asphalt Technology test track). IRI measurements with time suggest that initial acceptance testing can be conducted within 7 days, which allows more flexibility in scheduling by the agency. Limited traffic also slightly reduces the IRI values, which is to the contractor's advantage. IRI values are suggested for two-lane county roads and medium- to high-traffic facilities. Separate IRI ranges are indicated for each of these categories on the basis of the type of HMA construction: new, repair and overlay, and mill and overlay. These ranges are set for best and good practices (continuous paving, no stoppages; consistent supply of trucks, very short stops). IRI values greater than 125 in./mi in any given 25-ft interval indicate a bump; bumps can be ground so that these areas have IRI values of less than 100 in./mi.

Developing QC/QA Specifications for Hot Mix Asphalt Concrete in Illinois

1997 ◽  
Vol 1575 (1) ◽  
pp. 66-74 ◽  
Author(s):  
Arti Patel ◽  
Marshall Thompson ◽  
Eric Harm ◽  
William Sheftick
Keyword(s):  
Quality Management ◽  
Asphalt Concrete ◽  
Hot Mix Asphalt ◽  
Management Program ◽  
Department Of Transportation ◽  
Certification Program ◽  
Aggregate Gradation ◽  
Percent Increase ◽  
And Performance

The Illinois Department of Transportation (IDOT) has recently undertaken a quality management program to improve the quality of construction, allow more innovation, and reduce IDOTs management of industry construction programs. The Asphalt Concrete (AC) Quality Control/Quality Assurance (QC/QA) program is a significant part of this quality management program. IDOT accredits the success of the AC QC/QA program to gradual implementation and contractor and industry involvement. In 1991, four projects were constructed under a newly developed QC/QA specification. After reviewing and evaluating feedback from the contractors and IDOT personnel, the specification was revised for use on 1992 projects. In 1992, IDOT let 30 QC/QA projects, and in 1993, 65 QC/QA projects. In 1994 and 1995, most AC projects containing over 225 metric tons (250 tons) of hot-mix asphalt (HMA) were designated as QC/QA projects. In conjunction with this effort on AC quality, an aggregate certification program was implemented. The program ensures that aggregate gradation is highly controlled and is acceptable for incorporation into the mixture. Training programs for contractor QC and aggregate certification were also implemented. Analysis of the data indicates an increase in uniformity of the HMA, potentially leading to a 15 percent increase in fatigue life. IDOT is now examining the implications of developing end-result and performance-related specifications (ERS/PRS) for the AC QC/QA program. In the summer of 1996, one QC/QA project was shadowed and evaluated based on newly developed ERS/PRS.

INVESTIGATION OF TRANSVERSE CRACKS IN ANNULAR WELDED JOINTS OF MAIN GAS PIPELINES LINEAR PART

2021 ◽  
pp. 34-41
Author(s):  
V. A. Zaznobin ◽  
A. V. Nekrasov ◽  
A. V. Pankratov
Keyword(s):  
Welded Joints ◽  
Linear Part ◽  
Correct Identification ◽  
Gas Pipelines ◽  
Destructive Testing ◽  
Transverse Cracks ◽  
Additional Control ◽  
Non Destructive

Statistics of accidents and incidents on main gas pipelines in recent years indicate that almost half of the technogenic events occur due to depressurization in the area of annular welded joints, mainly joints containing defects made during construction and installation work during the construction of gas pipelines. The assessment of the degree of danger and the timing of external inspection and repair or replacement of defective annular welded joints largely depends on the quality of non-destructive testing, the correct identification of the types of defects and the objective determination of their geometric dimensions. To increase the reliability of the assessment of the degree of danger of the detected defects, it is necessary to use additional control methods, in particular, destructive ones. The paper presents the results of surveys and tests of metal fragments of annular welded joints of main gas pipelines containing transverse cracks of annular welded joints in order to determine the causes of the formation of these defects and to assess the degree of danger of the detected transverse cracks of the installation welds of main gas pipelines.

Detecting and Correcting Localized Roughness Features

2015 ◽  
Vol 2525 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Gary J. Higgins
Keyword(s):  
Asphalt Pavements ◽  
Minimum Length ◽  
Accurate Data ◽  
Department Of Transportation ◽  
Profile Data ◽  
Diamond Grinding ◽  
Significant Difference ◽  
Roughness Index ◽  
Colorado Department

Data collected by inertial profilers on new asphalt pavements in Colorado in 2012 were used to analyze the effectiveness of the localized roughness specification in Colorado. For the analyzed projects, data were collected before any corrections were made as well as after diamond grinding had been performed to remove areas of localized roughness. The data indicated that localized roughness features having a half-car roughness index (HRI) lower than 175 in./mi were rarely addressed during correction. However, about half the localized roughness features that had an HRI of 175 to 200 in./mi were successfully addressed during correction. Localized roughness features having an HRI greater than 200 in./mi appeared to be successfully addressed during correction. The analysis indicated a significant difference in the localized roughness locations identified by AASHTO R 54 and the Colorado Department of Transportation (DOT) method of detecting localized roughness. The Colorado DOT procedure specifies a minimum length for a roughness feature that is to be corrected, but AASHTO R 54 does not. This paper shows that collecting accurate profile data and analyzing the data to determine localized roughness locations are not enough. The identified locations must be correctly marked on the pavement in the field so that the feature does not cause localized roughness. This paper presents a procedure not only for collecting accurate data but also for accurately marking the roughness features in the field. It is shown that it is possible to locate and correct localized roughness accurately to the current thresholds as set by AASHTO R 54.

Effect of Performance Warranties on Cost and Quality of Asphalt Pavements

2007 ◽  
Vol 2040 (1) ◽  
pp. 100-106 ◽  
Author(s):  
Scott Shuler ◽  
Tim Aschenbrener ◽  
Robert DeDios
Keyword(s):  
Asphalt Pavements
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