Sliding Plate Microviscometer for Rapid Measurement of Asphalt Viscosity in Absolute Units

Abstract

A sliding plate microviscometer for determining the viscosity of asphalt in absolute units is described which utilizes the same constant temperature water baths normally found in control and materials testing laboratories. The instrument is sufficiently accurate and simple to permit bringing the measurement of viscosity in fundamental units into the control laboratory and eventually into asphalt specifications. The sliding plate microviscometer is suitable for routine measurement of viscosity-temperature relationships and viscosity-shear rate dependence. It is compact, rugged, and simple to operate and has a working range of 100 to 100 billion poises. This range permits overlapping with a capillary viscometer in the low viscosity region and allows measurement of the viscosity of the hardest paving grade asphalt at 32 F. Methods for expressing the viscosity-temperature relationship of asphalt are reviewed. Two equations which give straight-line relationships between asphalt viscosity and temperature are discussed. Data obtained with the microviscometer are presented to illustrate these relationships.

Analiza mogućnosti primjene proizvoda pirolize kao veziva u asfaltnim mješavinama

“…This is contrary to our expectations because Airey et al discovered in their research that synthetic binder has a flatter slope, compared to the curve for bitumen derived from crude oil [26]. A steeper slope means smaller temperature range of applicability, but at the same time the binder is more susceptible to the change of viscosity with temperature [27].…”

A review of asphalt and asphalt mixture aging

“…Treatments have focused on accelerating aging via temperature, oxidation and photo degradation. Myriad treatments have been used to age asphalt binders (Bahia et al, 1998;Dow, 1903;Edler et al, 1985;Griffin et al, 1955;Halstead and Zenewitz, 1961;Hveem et al, 1963;Zube and Skog, 1963;Kemp and Predoehl, 1981;Lee, 1973;Lewis and Welborn, 1940;Parmeggiani, 2000;Petersen, 1989;Qi and Wang, 2003;De la Roche et al, 2009;Traxler, 1963) and asphalt mixtures (Bell, 1989;Hugo and T. Kennedy, 1985;Kemp and Predoehl, 1981;Khalid and Walsh, 2000;Korsgaard et al, 1996;Pauls and Welborn, 1952;Von Quintus et al, 1991;Scholz, 1995). The thickness of asphalt cement film, which coats the aggregates, and asphalt mixtures' air void content have been considered regarding aging.…”

“…One of the first mathematical expressions for asphalt hardening was the Aging Index (AI) (Griffin et al, 1955). It represented the asphalt viscosity ratio of a 5 micron asphalt sample before and after being subjected to a 2-hour aging treatment at 107°C:…”

“…Models have studied asphalt before and after aging; they have analysed the chemical, mechanical and rheological pattern of asphalt subjected to aging, but they cannot be reproduced in the field as they are based on isolated analysis of variables. For example, the Aging Index (Griffin et al, 1955) evaluated a sample's rheological changes after several temperature variations. Daniel's mechanical model evaluated the strain changes of a sample subjected to different loads.…”

Oxidation of Asphalt Films Measured by Light Scattering

“…A new technique developed later (Griffin et al, 1955) evaluated the increase in viscosity at 25°C. caused by heating 5-micron films of asphalt in a dark, air oven for 2 hours at 107.2°C.…”