An Evaluation of Lower Mixing Temperatures for Bituminous Paving Mixes

摘要

The primary objective of this project is to investigate the economic potential and the engineering properties of hot plant mixed bituminous mixes produced at lower than normal mixing temperatures. This was accomplished by monitoring plant and field operations of a hot bituminous paving project in which approximately 52 % of the base and binder courses were mixed at 225 degrees F (+25 degrees F) instead of the normal 300 degrees F (+25 degrees F). No significant changes were noted in the engineering properties between the normal and lower temperature mixes. Plant and field conditions were not adversely affected. An energy analysis pointed out a 20.6% reduction in energy consumption, largely due to savings of dryer fuel. The state realized no direct financial benefit from the procedure since the regular and lower temperature mixes were bid at the same price.