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Accession Number PB2014-100893
Title Field Performance Evaluations of Illinois Aggregates for Subgrade Replacement and Subbase: Phase II.
Publication Date Apr 2013
Media Count 186p
Personal Author D. Mishra E. Tutumluer
Abstract The project objective was to validate the results from ICT Project R27-1, which characterized in the laboratory the strength, stiffness, and deformation behaviors of three different aggregate types commonly used in Illinois for subgrade replacement and subbase applications, through accelerated loading of full-scale pavement working platform test sections. Six different test cells were constructed at different combinations of aggregate material quality and subgrade strength, and were tested to failure using the University of Illinois Accelerated Transportation Loading Assembly (ATLAS). Each cell was tested along two different wheel paths representing two different aggregate layer moisture contents (Cells 1-5), or geotextile reinforcement conditions (Cell 6). Performances under loading were monitored through surface profile measurements as well as transverse scanning with ground-penetrating radar (GPR). Field and laboratory test results highlighted the importance of considering aggregate quality in the thickness design of aggregate layers for construction platforms. Thick layers of uncrushed gravel placed over a weak subgrade mainly underwent internal shear failure due to excessive movement of the aggregate particles. Crushed aggregate layers constructed with high relative compaction, on the other hand, showed significantly higher resistance to internal shear deformation and permanent deformation accumulations. Prolonged exposure to moisture and freeze-thaw effects was found to be beneficial for a crushed dolomite material with high amounts of nonplastic fines probably due to carbonate cementation within the fine fraction. Failure of test sections under flooded conditions was primarily caused by excessive deformation in the subgrade layer. Recommendations were made based on the study findings for improved material selection and thickness designs of aggregate working platforms.
Keywords Aggregates
Base courses
Deformation
Freezing
Illinois
Laboratory tests
Material properties
Moisture
Pavements
Performance evaluation
Replacing
Rock properties
Stiffness
Strength
Subgrades
Thickness


 
Source Agency Federal Highway Administration
NTIS Subject Category 50D - Soil & Rock Mechanics
50C - Construction Equipment, Materials, & Supplies
50A - Highway Engineering
Corporate Author Illinois Univ. at Chicago Circle. Urban Transportation Center.
Document Type Technical report
Title Note N/A
NTIS Issue Number 1403
Contract Number N/A

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