Asphalt foam collapse test methods and related apparatus

A method for determining foamed asphalt quality, the method comprising:

• (a) providing a foamed asphalt comprising an asphalt medium and a plurality of bubbles dispersed throughout the asphalt medium;
• (b) allowing the foamed asphalt to decay and measuring the height of the foamed asphalt along a measurement axis and as a function of time during decay to provide a height time series for the decaying foamed asphalt, wherein the measurement axis is substantially parallel to a decay direction defined by the decaying foamed asphalt;
• (c) determining from the height time series at least one foam quality parameter;
• and
• (d) comparing the foam quality parameter with at least one corresponding foam quality set point.

An apparatus for measuring foamed asphalt quality, the apparatus comprising:

• (a) a vessel for containing a foamed asphalt sample, the vessel defining a foam decay direction;
• and
• (b) a means for measuring the height of a foamed asphalt sample in the vessel as a height time series in real time,
• wherein:
• (i) the height measuring means defines a measurement axis, and
• (ii) the height measuring means is positioned remotely from the vessel and such that the measurement axis is substantially parallel to the foam decay direction.