Details:

Creators:
Cosentino, Paul J. ; Bleakley, Albert M. ; Armstrong, Alexander T. ; Misilo, Thaddeus J. ; Sajjadi, Amir M.
Cosentino, Paul J. ; Bleakley, Albert M. ; Armstrong, Alexander T. ; Misilo, Thaddeus J. ; Sajjadi, Amir M. Less -
Corporate Creators:
Florida Institute of Technology. Civil Engineering Dept.
Subject/TRT Terms:
[+]
Base Course (Pavements) Crumb Rubber Geotechnical Engineering Reclaimed Rubber Soil Stabilization Subgrade Materials
Publication/ Report Number:
BDK81 977-03
Resource Type:
Tech Report
Geographical Coverage:
Florida
Corporate Publisher:
Florida. Dept. of Transportation. Research Center
Abstract:
Over 250 million scrap tires are generated annually in the U.S. Historically, a significant portion of these tires

have been processed into finely ground tire rubber (GTR), or crumb rubber, for use as an additive in hot mix asphalt

(HMA) pavements to improve pavement performance. Recently, improved synthetic polymer additives have been

developed that more economically provide the same performance improvements as GTR. This development has

decreased the demand for GTR in HMA, potentially freeing supplies of GTR for other applications.

Over the past two decades, the Florida Department of Transportation (FDOT) has conducted a significant amount

of research on ways to re-use waste materials such as energy generation ash, tires, glass, reclaimed asphalt pavement,

and reclaimed concrete in roadway construction. FDOT initiated this study to investigate whether blending GTR with

subgrade soils would be a beneficial practice.

The objective of this research was to determine the effect of GTR on subgrade soil engineering properties. Three

representative sizes of GTR, 1 inch (25.4 mm), 3/8 inch (9.51 mm), and #40 (0.422 mm) were blended in varying

percentages with three subgrade soils. Subgrade soils were selected with low, medium, and high limerock bearing ratio

(LBR) strength. Blends were evaluated with 4, 8, 16, 24, and 32% GTR by volume. Blends were evaluated for grain

size, moisture-density, LBR, permeability, consolidation, resilient modulus (Mr), and creep.

Ground tire rubber does not make a good stabilizing agent for subgrade soils. Blending GTR with subgrade soils

reduced both LBR and Mr significantly. Blending has minimal impact on consolidation or permeability. Blending

increases creep in the tested soils, however the creep remained within acceptable limits.

Blending GTR with soil did reduce the density of the blend. Additional research should be conducted to evaluate

whether soil/GTR blends would be suitable for low-density fill applications where the benefits from reduction in

vertical and horizontal soil pressures would offset the reduction in strength.


Format:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:b782d5f7a51cc87ef851428e615cf3830d785ef96b40dc208c9aebda4a941212
Download URL:
https://rosap.ntl.bts.gov/view/dot/27311/dot_27311_DS1.pdf
File Type:

Supporting Files

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