MECHANICAL PROPERTIES OF BINDER-FREE ROAD COURSES
MECHANISCHE KENNWERTE BINDEMITTELFREIER STRASSENBEFESTIGUNGSSCHICHTEN
A ROAD BASE HAS IN ADDITION TO ITS TRAFFIC-CARRYING FUNCTION, A MECHANICAL FUNCTION. ROAD SUBSOILS ARE GENERALLY PRONE TO LARGE DEFORMATIONS AND HAVE STRENGTHS WHICH ARE TOO LOW. THE BUILD UP OF THE TWO PROPERTIES REQUIRED STIFFNESS AND STRENGTH IS BROUGHT ABOUT BY PLACING AND COMPACTING CONSECUTIVE LAYERS OF RESISTANT AND EASILY DEFORMABLE MATERIALS. IN CERTAIN COURSES NON-BOUND MINERAL AGGREGATE MIXES ARE USED FOR THIS PURPOSE. THE DETERMINATION OF THE STIFFNESS AND STRENGTH PARAMETERS OF THESE COURSES IS CARRIED OUT BY PLATE BEARING TESTS. WITH THOSE THE DEFORMATION MODULUS E(V) OF ALL COURSES BENEATH THE TEST LEVEL IS DETERMINED. THE SEPARATE COURSE STIFFNESS CAN BE CALCULATED BY THE INCREASE IN THE E(V) VALUES FOR INCREASING COURSE SEQUENCE. HOWEVER WHEN USING CONSECUTIVE MEASUREMENTS FOR EXAMPLE IN ROAD CONSTRUCTION SUBSEQUENT INCREASE IN STIFFNESS OF THE LOWER COURSE IS NOT OBTAINED. THE RESULT FOR THE MOST RECENTLY LAID COURSE IS RENDERED FALSE BY THIS. THE AUTHOR INVESTIGATES IN DETAIL THE INFLUENCE OF LOADING AND COMPOSITION ON BINDER-FREE AGGREGATES - MATERIALS WITH LOW TENSILE STRENGTH. IN PARTICULAR THE INFLUENCES ARE STUDIED OF GRAIN SHAPE AND SURFACE AREA ON THE DEFORMATION CURVE ACCORDING TO ELASTIC THEORY AND THE COMPLICATED RELATIONSHIPS ARE SHOWN IN GENERAL TERMS. THE VALUES OBTAINED BY THE PLATE BEARING METHOD CANNOT BE USED TO DETERMINE THE RELATIONSHIPS. HOWEVER THERE APPEARS TO BE NO WAY MATHEMATICALLY OF OBTAINING CORRECTION FACTORS FROM THE DEFORMATION CURVES. FOR THE COURSE STIFFNESS OF AN AGGREGATE MIXTURE THE ABILITY TO WITHSTAND STRESS IS A FURTHER IMPORTANT QUALITY CHARACTERISTIC, SINCE WITH ITS AID CERTAIN TENSILE STRESSES CAN BE COMPENSATED.
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/issn/00281034
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Authors:
- Affeldt, K
- Publication Date: 1978-7
Language
- German
Media Info
- Pagination: 11-5
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Serial:
- NATURSTEIN-IND
- Volume: 14
- Issue Number: 4
- ISSN: 0028-1034
Subject/Index Terms
- TRT Terms: Base course (Pavements); Continuously graded aggregates; Deformation; Elasticity (Mechanics); Interlocking aggregates; Loads; Mix design; Particles; Shape; Stiffness; Surfaces; Tension; Theory; Thickness
- ITRD Terms: 4598: Continuously graded aggregate; 5595: Deformation; 5912: Elasticity; 4567: Interlocking (aggregate); 5567: Load; 4714: Mix design; 4511: Particle; 2961: Roadbase; 9073: Shape; 5931: Stiffness; 6438: Surface; 5502: Tension; 9078: Theory; 5933: Thickness
- Subject Areas: I36: Aggregates;
Filing Info
- Accession Number: 01288974
- Record Type: Publication
- Source Agency: Forschungsgesellschaft für Straßen- und Verkehrswesen (FGSV)
- Files: ITRD
- Created Date: Nov 21 2010 1:34AM