ABSTRACT
Abstract This work attempts to study the behaviour of the bitumens when forming bituminous mixtures at high temperatures of ser v i c e i n highway pavements. The used proceeding has been the Marshall method ASTM D 1559-82, modifiying the breakage temperature of the sample t e s t . These temperatures o s c i l l a t e from 45QC up to 80QC, from 5 to 5 degrees. In order to f a c i l i t a t e the study of the obtained r e s u l t s i n r e l a t i o n to the thermic s u s c e p t i b i l i t y of the te s t e d mixtures, the ASTM Standard Test Method f o r Viscosity-Temperature Chart for Asphalts, ASTM D 2493, that r e l a t e s the temperature and the absolute v i s c o s i t y , has been adopted. The anal y s i s of the obtained experimental r e s u l t s shows that bitumens with very s i m i l a r penetration but d i f f e r e n t source, composition and nature present d i f f e r e n t r h e o l o g i c a l behaviour i n the range of servic e temperatures. A marked change of r h e o l o g i c a l behaviour i n a l l t e s t e d mixtures, about 55QC, has been detected. This change i s q u a n t i f i e d by the slopes value c a l c u l a t e d from the l i n e a l regression equations. Keywords ; Bituminous Mixtures, Marshall Method, Thermic S u s c e p t i b i l i t y , Viscosity-Temperature Chart, Rheologic a l Behaviour.
