The Effect of Pre-heating Duration and Temperature Conditioning on Rheological and Rotational Viscosity of Asphalt Bitumen Modified with Nano Clay, Nano Hydrated Lime, and Nano Olive Husk Binders
Abstract
Overheating asphalt bitumen is well recognized to result in oxidation and the hardening of the material. Heating bitumen is a crucial step in preparing samples, and it is vital to determine the specific time and temperature settings for the oven used in laboratory testing. The current AASHTO guidelines do not include specific instructions for the precise oven settings required for preparing bitumen samples before conducting laboratory tests. This research aims to assess the impact of varying oven heating time and pouring temperature on the rheological characteristics of control and modified binders, namely nano clay (NC), nano hydrated lime (NHL), and nano olive husk (NOH), during sample preparation. Rheological qualities are assessed by using a rotational viscometer and a dynamic shear rheometer at temperatures relevant to the grade being tested. Three different temperatures (150, 165, and 180°C) were used to test a control bitumen and two modified binders with percentages of 3% and 5%. The binders were evaluated in their original, un-aged conditions for a duration of 2 hours. The research suggests a heating temperature of 150°C and a duration of 2 hours is a suitable method for adequate preparation before conducting routine laboratory tests.