This report focuses on the importance of the conditioning time preceding the measurement of rheological quantities for bitumens which have undergone preliminary cooling. It was obtained that, for the studied bitumens and the used equipment, the conditioning time carries out a change of the temperature dependency law of mechanical properties, with an alteration of shift factors which is significant especially at low temperatures. The range of the investigated temperatures (2÷35°C) has meant understanding the evolution of the phenomenon and assuming a mathematical modelling by an asymptotic exponential law. To the extent of the presented results, it is possible to conceive that bitumen rheological behaviour is governed by the loading time and temperature as well as the conditioning time. Notwithstanding this complex dependence on more than one variable it has been however ascertained that, for the studied materials and testing conditions, the rheological properties could be expressed as a function of the loading time only, in virtue of a loading time – temperature – conditioning time superposition principle, which is suggested here below.
Influence of the Conditioning Time on the Rheological Properties of Bitumens at Intermediate Temperatures: Loading Time – Temperature – Conditioning Time Superposition Principle
CERNI, Gianluca
2001
Abstract
This report focuses on the importance of the conditioning time preceding the measurement of rheological quantities for bitumens which have undergone preliminary cooling. It was obtained that, for the studied bitumens and the used equipment, the conditioning time carries out a change of the temperature dependency law of mechanical properties, with an alteration of shift factors which is significant especially at low temperatures. The range of the investigated temperatures (2÷35°C) has meant understanding the evolution of the phenomenon and assuming a mathematical modelling by an asymptotic exponential law. To the extent of the presented results, it is possible to conceive that bitumen rheological behaviour is governed by the loading time and temperature as well as the conditioning time. Notwithstanding this complex dependence on more than one variable it has been however ascertained that, for the studied materials and testing conditions, the rheological properties could be expressed as a function of the loading time only, in virtue of a loading time – temperature – conditioning time superposition principle, which is suggested here below.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
