00731154

Component

https://doi.org/10.3141/1547-14

http://scholar.google.com...czak&publication_year=1996

The major objective of the research was to conduct a study into the feasibility of using shredded rubber as a partial replacement for aggregate within conventional base and subbase materials in a flexible pavement system. A graded aggregate base and sand subbase meeting specifications for the Maryland State Highway Administration were used. The rubber used in the study consisted of a shredded product with 60 to 70% retained on a 9.5-mm (3/8-in.) sieve. This size was selected because of the relatively inexpensive cost to produce it and because of its adaptability to an aggregate blend. Modified and standard Proctor, California bearing ratio (CBR), and resilient modulus tests were conducted on the base/subbase-rubber blends with up to 15% rubber content by weight. The aggregate base blend resulted in significant decreases in both CBR and nonlinear resilient modulus at 15% rubber. These significant reductions led the authors to conclude that the use of shredded rubber in a dense-graded aggregate base course is not feasible. In contrast, the sand-subbase blends resulted in insignificant changes to the CBR, friction angle, permeability, and resilient modulus at higher rubber percentages. It was concluded that the sand-rubber subbase exhibits little change compared with the virgin sand-subbase material. As a result the use of shredded rubber may be a technically feasible alternative in the construction process. Finally, two constitutive models were used in the resilient modulus analysis: the conventional K sub 1, K sub 2 model and a universal model incorporating the octahedral stress term (k sub 1, k sub 2, k sub 3 model). Direct comparisons revealed greatly improved predictability and accuracy with the universal model for assessing the nonlinear behaviors of both aggregate types evaluated.

This paper appears in Transportation Research Record No. 1547, Aggregate and Material Tests and Properties Related to Performance.

English

p. 96-106

1996

Transportation Research Record

0309059151

Figures (12) ; References (8) ; Tables (4)

Base course (Pavements); California bearing ratio; Dense graded aggregates; Feasibility analysis; Flexible pavements; Friction; Mathematical models; Modulus of resilience; Nonlinear systems; Permeability; Rubber; Sand; Shredding; Soil compaction test; Solid wastes; Subbase materials; Testing; Tires

Friction angle; Nonlinear behavior; Proctor compaction test; Scrap tires

Geotechnology; Highways; Materials; Vehicles and Equipment; I33: Other Materials used in Pavement Layers

TRIS, TRB

Feb 3 1997 12:00AM

• AGGREGATE CHARACTERISTICS GOVERNING PERFORMANCE OF SEAL COAT HIGHWAY OVERLAYS
• ANALYSIS OF RESILIENT MODULUS OF DENSE- AND OPEN-GRADED AGGREGATES
• COARSE AGGREGATE EFFECTS ON ELASTIC MODULI OF CONCRETE
• EFFECTS OF AGING ON FRESHLY DEPOSITED OR DENSIFIED CALCAREOUS SANDS
• EVALUATION OF FROST RESISTANCE TESTS FOR CARBONATE AGGREGATES
• EVALUATION OF LABORATORY PROCEDURES FOR AGGREGATE POLISH TEST
• EVALUATION OF PAVEMENT BEARING CHARACTERISTICS USING FLORIDA LIMEROCK BEARING RATIO TEST
• INFLUENCE OF AGGREGATE PROPERTIES ON PERFORMANCE OF HEAVY-DUTY HOT-MIX ASPHALT PAVEMENTS
• INFLUENCES ON PERMANENT DEFORMATION BEHAVIOR OF UNBOUND GRANULAR MATERIALS
• LINCOLN AVENUE RECLAIMED ASPHALT PAVEMENT BASE PROJECT
• SHAKEDOWN OF SUBGRADE SOIL UNDER REPEATED LOADING
• STEADY-STATE STRENGTH, RELATIVE DENSITY, AND FINES CONTENT RELATIONSHIP FOR SANDS
• TESTING METHODOLOGY FOR RESILIENT MODULUS OF BASE MATERIALS