RESEARCH INTO THE STRESSING OF PAVEMENT STRUCTURES. PART 2: DETERMINATION OF THE INFLUENCE OF THE BINDER CONTENT ON THE ALLOWABLE STRESS IN BITUMINOUSLY BOUND ROAD BASES UNDER REPEATED LOADING

BEITRAEGE ZUR ERFORSCHUNG DER BEANSPRUCHUNG VON FAHRBAHNKONSTRUKTIONEN. TEIL 2: ERMITTLUNG DES EINFLUSSES DES BINDEMITTELGEHALTS AUF DIE ZULAESSIGE BEANSPRUCHUNG BITUMINOES GEBUNDENER TRAGSCHICHTEN UNTER WIEDERHOLTEN BELASTUNGEN

THE AIM OF THIS WORK IS TO DETERMINE THE INFLUENCE OF THE BINDER CONTENT OF BITUMINOUS ROAD BASES ON THE DYNAMIC SHEAR MODULUS AND THE TIME-SHEAR STRENGTH. FOR THE EXPERIMENTAL PART OF THE WORK, A SHEAR TESTING MACHINE WHICH WAS DEVELOPED IN THE TESTING INSTITUTE FOR ROAD TRANSPORT OF THE TECHNICAL UNIVERSITY OF MUNICH WAS EMPLOYED. THIS SUBJECTED THE TEST SPECIMENS TO AN ECCENTRIC PULSATING HARMONIC SHEAR STRESS USING A CROSS HEAD. THE TESTS WERE CARRIED OUT AT A FREQUENCY OF 8.33 HZ AND FIRSTLY DEMONSTRATED A NEW STRONG INFLUENCE OF TEMPERATURE ON THE PARAMETERS STUDIED. CHANGES IN THE BINDER CONTENT PARTICULARLY INFLUENCES THE DYNAMIC SHEAR MODULUS AND TO A LESSER DEGREE THE TIME-SHEAR STRENGTH. RELATIVELY LOW BINDER CONTENTS GIVE RISE TO CONSIDERABLY HIGHER DYNAMIC SHEAR MODULI AND MARGINALLY INCREASED TIME-SHEAR STRENGTH. HIGHER BITUMEN CONTENTS HAVE THE OPPOSITE EFFECT. IN CONSIDERATION OF THE LIFESPAN OF BITUMINOUS ROADBASES, ONE MUST CONSIDER THAT WITH LOWER BITUMEN CONTENT LARGER STIFFNESSES GIVE RISE TO HIGHER STRESSES, WHICH BECAUSE OF THE SMALL INCREASE IN THE TIME-SHEAR STRENGTH CANNOT BE EVENED OUT. THE HIGHER STIFFNESS OF BITUMINOUS ROAD BASES WHICH IS DESIRABLE AS A RESISTANCE TO PLASTIC DEFORMATION, IS BETTER ACHIEVED THROUGH THE USE OF HARDER BINDERS THAN BY THE REDUCTION IN THE BINDER QUANTITIES. DYNAMIC SHEAR MODULUS AND TIME-SHEAR STRENGTH WILL ALSO BE SMALLER WITH INCREASING VOID CONTENT, AND THIS HAS A FAVOURABLE EFFECT ON THE LIFE SPAN. A LOWER LIMIT FOR THE VOID CONTENT OF BITUMINOUS ROADBASES RESULTS FROM THE DEMAND FOR SUFFICIENT STABILITY.

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  • German

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  • Accession Number: 01293134
  • Record Type: Publication
  • Source Agency: Forschungsgesellschaft für Straßen- und Verkehrswesen (FGSV)
  • Files: ITRD
  • Created Date: Nov 21 2010 3:52AM