Indigenous development and testing of rotational viscometer for bituminous binders

The measurement of consistency of construction materials has been the keen interest of many researchers in the recent past. It can be observed that the empirical methods are being used for measuring consistencies of Bitumen, Cement Paste, Soil Mass and Fresh Concrete in many countries. The need of the hour is to develop instrumentation for measuring the consistencies based on Mechanistic Approaches which essentially depend on the assessment of deformation behavior in response to application of loads. This paper presents a method by which a Rotational Type Viscometer can be devised. The instrument is validated with glycerin at a specified temperature and further used to measure the viscosity of bitumen for temperatures ranging upwards from the softening point. Two terms; Static effective & Dynamic Effective Viscosity have been introduced for bitumen and a methodology has been suggested to assess these parameters.