ABSTRACT
A b s t r a c t Within the framework of a research p r o j e c t , supported by the J o i n t Study Group of I n d u s t r i a l Research A s s o c i a t i o n s (AIF), comparative i n v e s t i g a t i o n s were c a r r i e d out i n r e spect to the mechanical behavior of bituminous base course l a y e r s w i t h and without re c y c l e d asphalt. A t e s t t r a c k was paved, c o n s i s t i n g of two subsections, a l t e r n a t i v e l y u t i l i z i n g base course m a t e r i a l s with 30% r e c y c l e d asphalt and with 100% unused m a t e r i a l s . From both s e c t i o n s samples were taken and were prepared as specimen to perform c o o l i n g - o f f t e s t s (executed i n TU Braunschweig), dynamic f l e x u r a l - t e n s i l e t e s t s and dynamic creep t e s t s . The d i s c u s s i o n of the t e s t r e s u l t s i n d i c a t e s t h a t the per formed t e s t s are s u i t a b l e f o r the a n a l y s i s and the evalu a t i o n of bituminous base course m a t e r i a l s mixed wi t h r e cyc l e d asphalt. Keywords : Behavior of bituminous base course m a t e r i a l s with r e c y c l e d asphalt, c o o l i n g - o f f t e s t s , dynamic f l e x u r a l - t e n s i l e t e s t s , dynamic creep t e s t s
1 Introduction
The use of re c y c l e d asphalt i n bituminous base course ma t e r i a l s i s being s a t i s f a c t o r i l y p r a c t i c e d s i n c e s e v e r a l years. The t e c h n i c a l as w e l l as the c o n t r a c t u a l r e q u i r e ments are already formulated f o r the employment. However, i t i s up t o date not yet adequately c l a r i f i e d , whether the reuse of asphalt m a t e r i a l s would i n f l u e n c e the homogeneity of the r e s u l t i n g mix and i t s mechanical behavior. This problem which i n the meantime represents one of the main f i e l d s of research i n the asphalt technology was the objec t i v e of a research p r o j e c t , c a r r i e d out at the I n s t i t u t e f o r Highway and R a i l r o a d Engineering of U n i v e r s i t y of Karlsruhe and supported by the Study Group of I n d u s t r i a l Research A s s o c i a t i o n s (AIF). This paper presents the meth odology u t i l i z e d w i t h i n the scope of the research p r o j e c t and the r e s u l t s of the laboratory t e s t s , d e s c r i b i n g the mechanical behavior of bituminous base course m a t e r i a l s .
