What is used to evaluate the rheology of asphalt?

When evaluating the rheology of coal tar pitch, the following methods are usually adopted:

1. Viscosity measurement: Viscosity is one of the important indexes to measure fluid flow performance. By measuring the viscosity of coal tar pitch at different temperatures, its fluidity can be evaluated. Generally speaking, with the increase of temperature, the viscosity of coal tar pitch will decrease and the fluidity will improve. However, if the temperature is too high, coal tar pitch may undergo thermal decomposition or oxidation, resulting in increased viscosity and poor fluidity. Therefore, it is the key to choose the appropriate temperature for measurement.

2. Flow curve test: By measuring the flow curve of coal tar pitch at different temperatures, we can understand its rheology more comprehensively. The flow curve can reflect the fluidity, plasticity and stability of coal tar pitch at different temperatures. Generally speaking, the ideal flow curve should be smooth without abrupt change or fluctuation. If the flow curve is not smooth or has abnormal fluctuation, it indicates that there is a problem with the rheology of coal tar pitch.

3. Softening point test: Softening point refers to the temperature at which coal tar pitch begins to flow under certain conditions. By measuring the softening point of coal tar pitch, its fluidity at a certain temperature can be evaluated. Softening point is one of the important indexes to measure the high temperature resistance of coal tar pitch, and it is also one of the important technical indexes in road construction. Generally speaking, the higher the softening point, the better the high temperature resistance and fluidity of coal tar pitch.

4. Aging test: Because coal tar pitch will be affected by environmental factors during its use, its rheology will also change. Aging test can evaluate the rheological properties of coal tar pitch under different environmental conditions. Aging test usually includes thermal aging, oxidative aging, ultraviolet aging and so on. If the rheology of coal tar pitch changes after aging test, it indicates that its quality is unstable or defective.