Details:

Alternative Title:
Rubber modified asphalt Concrete (METRO RUMAC) evaluation : Lakeview Junction - Matney Road Section (OR #50) , Pacific Highway - 42nd Street Section (OR #227).
Creators:
Miller, Bo
Corporate Creators:
Oregon. Department of Transportation. Engineering Services Section
Subject/TRT Terms:
[+]
Admixtures Asphalt Concrete Asphalt Pavements Base Course (Pavements) Costs Crumb Rubber Field Tests Ground Tires Mix Design Overlays (Pavements) Pavement Asphalt Rubber
Publication/ Report Number:
OR-RD-96-03
Resource Type:
Tech Report
Geographical Coverage:
Oregon
Corporate Publisher:
Oregon. Department of Transportation. Engineering Services Section
Abstract:
This report covers the construction in 1992 of test sections on two projects using asphalt concrete modified with tire rubber. One project's test sections are part of a single lift overlay on a lightly traveled two-lane road south of Klamath Falls, Oregon. The other project's test sections are part of the base course of a three-lift overlay on a heavily traveled four-lane divided highway between Eugene and Springfield.

All test sections use a dense-graded rubber modified asphalt concrete developed for the METRO agency of the Portland, Oregon urban area (METRO RUMAC). Control sections were paved with conventional asphalt concrete adjacent to the test sections. The test sections are compared to these control sessions.

The METRO RUMAC was successfully blended for both projects by adding unopened bags of the rubber to the pugmill of the mix supplier's batch plants. The rubberized mixes could be placed and compacted by conventional equipment. One project's test sections could not be rolled to the desired density. An improper mix gradation may have prevented compaction. The other project's test sections could be compacted to the desired density. Immediately after compaction, construction traffic traveled on one project's hot METRO RUMAC pavement, and the vehicle's tires adhered to and damaged the surface.

Experience on these projects indicate that the specification limits for crumb rubber need to be revised, and in some cases, the percentage of rubber required in the METRO RUMAC needs to be lowered to obtain satisfactory mix properties. In addition, solvent extractions were successfully used on one project to determine the overall gradation of the METRO RUMAC.

Sampling and testing methods were developed to see if the crumb rubber added to these pavement met the METRO RUMAC specifications.

After construction, both project's METRO RUMAC and conventional pavement sections had similar appearance and surface friction values. One one project, the test and control section's ride quality was compared, and the METRO RUMAC and conventional mixes had similar characteristics.

The METRO RUMAC mixes cost 1.3 to 2.0 times as much as their conventional counterparts. Much of this cost was due to addition of the rubber, and the extra asphalt required by the rubberized mixes.


Format:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:fb42f89d1041658cdc64ecb7cf214041be95a773d681e517853e7ef008707ef0
Download URL:
https://rosap.ntl.bts.gov/view/dot/22890/dot_22890_DS1.pdf
File Type:

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