Design and construction recommendations for thin overlays in Texas.
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



Publication Date Range:


Document Data


Document Type:






Clear All

Query Builder

Query box

Clear All

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


Design and construction recommendations for thin overlays in Texas.

Filetype[PDF-17.82 MB]

Select the Download button to view the document
This document is over 5mb in size and cannot be previewed
  • English

  • Details:

    • Publication/ Report Number:
    • Resource Type:
    • Geographical Coverage:
    • NTL Classification:
    • Abstract:
      Thin HMA overlays, laid at 1.0 inch or thinner, are cost-effective surface maintenance options. The primary focus of this research was

      to develop specifications for three such mixes: fine dense-graded mix (fine DGM), fine-graded stone matrix asphalt (fine SMA), and

      fine-graded permeable friction course (fine PFC). A number of slurry overlay systems were also evaluated, but to a lesser extent.

      Draft specifications for the three mix types were first developed based on the results of a literature/information search and a

      field investigation of 11 existing projects. The specifications included minimum material quality levels, laboratory performance

      criteria, and construction recommendations. To evaluate the design recommendations, extensive laboratory testing was performed on

      each of the three thin overlay mixes with five different aggregates. Of the 15 mixes attempted, 12 had acceptable designs in terms of

      the specified performance tests. For the most part, the draft specifications appeared to function well with minor alterations

      recommended. Testing also included two supplementary studies on the effects of screening type in fine SMA and the effects of

      recycled materials on both the fine SMA and fine PFC. Compaction of the fine SMAs was highly influenced by packing

      characteristics of the coarse and fine aggregates. Screening quality did not affect fine SMA rutting resistance, but did affect cracking

      resistance. Using recycled aggregates reduced rutting problems but increased cracking susceptibility; however, most mixes performed

      well suggesting that quality, well-engineered mixes can still have good performance when recycled materials are used in limited


      Concerning laboratory testing of slurry overlays, the applicability of the overlay tester/procedures and the three-wheel

      polishing device in testing should be further studied. In particular, a tie-in with actual field performance should be identified, perhaps

      with the Accelerated Pavement Test program.

      Six thin overlay projects, comprising 10 unique mix designs, were constructed and evaluated. Most projects were constructed

      without problems, though some encountered issues with over- and under-compaction. Initial performance has been very good,

      although, since all the sections are less than two years old, the long-term performance is still undetermined.

      The researchers recommend adapting the specifications accompanying this report, which require using high quality materials

      and passing strict laboratory performance tests on both the lab design and trial batch materials. They do not recommend incorporating

      recycled materials in these mixes, though preliminary results are promising. Guidelines for pavement evaluation and mix selection

      were also prepared, which recommend the use of certain thin overlay or slurry overlay options given the pavement, traffic, and climate


    • Format:
    • Main Document Checksum:
    • File Type:

    Supporting Files

    • No Additional Files

    More +

    You May Also Like

    Checkout today's featured content at

    Version 3.26