Measuring all these factors in a controlled laboratory environment has been exceedingly difficult, unless use Crack Sealing Machine; therefore theoretical calculations of thermal stress have often utilized simplifying assumptions in place of many of the aforementioned factors. Furthermore, current methods have not consider thermal cycling in the analysis as it is assumed that thermal cracking occurs in a single cold temperature event.
This method is currently used for the estimation of critical cracking temperature by researchers and designers in many Crack Sealing Machine procedures. However, this method does not take into account the glass transition behavior and physical hardening observed in asphalt binders, instead utilizing a constant coefficient of thermal expansion/contraction.
The increase in brittleness as well as the time dependent behavior of the material in this temperature range can have a detrimental effect on actual performance of Crack Sealing Machine. Furthermore, change in relaxation properties has been noted in asphalt and many polymers during physical hardening.
