Field verification of asphalt aging in hot mix plants.
Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.

Search our Collections & Repository

All these words:

For very narrow results

This exact word or phrase:

When looking for a specific result

Any of these words:

Best used for discovery & interchangable words

None of these words:

Recommended to be used in conjunction with other fields

Language:

Dates

Publication Date Range:

to

Document Data

Title:

Document Type:

Library

Collection:

Series:

People

Author:

Help
Clear All

Query Builder

Query box

Help
Clear All

For additional assistance using the Custom Query please check out our Help Page

i

Field verification of asphalt aging in hot mix plants.

Filetype[PDF-1.17 MB]


  • English
    • Details You May Also Like

    Details:

    • Creators:
    • Subject/TRT Terms:
    • Resource Type:
      Tech Report
    • Geographical Coverage:
      Oregon
    • Abstract:
      As a measure of the aging of asphalt concrete mixes in the mixing and placement process, a formula was developed to determine the percentage of expected change in asphalt viscosity at the time of paving (Lund and Wilson, 1984). A value of 30 or higher was used in 1983-84 for acceptance on paving projects. At the conclusion of the 1981-83 study, a follow-up survey was made of all projects. Two major areas of interest were covered in the follow-up questionnaire: 1) the characteristics of the asphalt mix and pavement at the time of placement, and 2) the characteristics of the pavement at the time of receiving the questionnaire (March, 1984).

      The responses to the questionnaire, even though they are subjective, appear to identify and confirm relationships between the "C" value and asphalt mix problems. The strongest correlation appears to be more with problems at the time of construction than with long term pavement performance problems. Using statistical tests, the significant problems that were identified during construction were tenderness, shoving and rutting, segregation and mix being too cold. The long term significant problems developing after construction were stripping and cracking.

      When the individual characteristics were evaluated, the great majority had the significance level peak at the less than 40 "C" value. That is, a greater percentage of the samples that were below 40 had some problems in the field.

      In early 1985, the Oregon Highway Department raised the minimum acceptable "C" value to 40. Mix with a value less than 40 is to be removed, or at the discretion of the Engineer. It may be left in place and a reduction in a Composite Pay Factor calculated.

      In 1985, "C" values were again analyzed to see if any changes had occurred since the 1981-1983 study. Forty-nine projects constructed or under construction from August 1983 to July 1985 were reviewed, from which 193 individual "C" values were obtained. Comparing the results with the 1981-1983 data, indicated that individual variables such as longer fuel type, dust collection system, and plant type no longer are associated with changes in "C" values. Instead, the entire operation (adjustment) of the asphalt plant is the major influence on the "C" value. due to plant adjustments, several contractors, have poor results in the past, have been able to raise their average "C" value.

    • Format:
      PDF
    • Collection(s):
    • Main Document Checksum:
    • Download URL:
    • File Type:

    Supporting Files

    • No Additional Files

    More +

    You May Also Like

    Checkout today's featured content at rosap.ntl.bts.gov

    Version 3.26