EVALUATION OF PAVEMENT BASE AND SUBGRADE MATERIAL PROPERTIES AND TEST PROCEDURES. INTERIM REPORT
The objective of this research was to develop simpler and less expensive procedures for characterizing the resilient properties (K sub 1 to K sub 3) and the strength parameters [cohesion (C) and angle of internal friction (phi)] of base and subgrade materials. Researchers accomplished this by developing prediction equations which use easy to obtain soil properties and by evaluating a modified Texas triaxial test procedure which can be used to determine both the strength and resilient properties of pavement materials. Researchers tested five subgrade soils, i.e., sand, lean clay, fat clay, silt, and sandy gravel, and four base materials, i.e., crushed limestone, caliche, shellbase, and iron ore gravel, according to Texas specifications to obtain a database of material properties for developing the prediciton equations. In developing this database, the strength parameters, C and phi, of the Mohr-Coulomb yield criterion, were obtained from standard Texas triaxial tests. For the resilient properties, compressive creep and recovery tests were run using AASHTO T-274 as a guide, to obtain the resilient moduli and Poisson's ratios of the materials tested at different stress states and moisture contents. The standard Texas triaxial test procedure, TEX-117-E, was modified to include a creep and recovery cycle before the test sample is loaded monotonically to failure. This loading sequence produced test data that allowed the estimation of the K sub 1 to K sub 3 resilient properties in addition to the strength parameters, C and phi. The strength and resilient parameters obtained from the modified Texas triaxial test were compared to those obtained from the standard Texas triaxial test and the compressive creep and recovery test. Researchers document the results of these comparisons, as well as the development of the equations for predicting the strength and resilient parameters of base and subgrade materials, in this report.
- Research study title: Movement of Superheavy Loads Over the State Highway System.
Arlington, TX United States 76011
Austin, TX United States 78763-5051
Washington, DC United States 20590
- Titus-Glover, L
- Fernando, E G
- Publication Date: 1995-11
- Features: Appendices; Figures; Photos; References; Tables;
- Pagination: 126 p.
- TRT Terms: Base course (Pavements); Clay; Coefficient of internal friction; Cohesion; Conglomerates; Crushed limestone; Equations; Forecasting; Iron ores; Modulus of resilience; Poisson distributions; Poisson ratio; Sand; Sandy gravels; Silts; Subgrade materials; Triaxial shear tests
- Uncontrolled Terms: Caliche; Triaxial tests
- Old TRIS Terms: Compressive creep and recovery tests; Mohr-coulomb criterion; Shellbase
- Subject Areas: Geotechnology; Highways; I42: Soil Mechanics;
- Accession Number: 00720308
- Record Type: Publication
- Report/Paper Numbers: FHWA/TX-96/1335-2, Res Rept 1335-2, TTI: 0-1335
- Contract Numbers: Study 0-1335
- Files: TRIS, USDOT, STATEDOT
- Created Date: Apr 29 1996 12:00AM