MultiCool is a user-friendly application that calculates the rate of cooling in an HMA mat during construction and was developed to help accurately predict asphalt pavement cooling time. It requires that the user input such items as the time of day (entered automatically according to the computer's clock), latitude, air temperature, wind speed, mix information and lift thickness for each HMA lift, type of material being paved over, its temperature and whether or not the soil or base are frozen.
The program then computes how quickly each lift of HMA will cool and when the next lift may be placed. This cooling rate prediction can help contractors better plan rolling operations to more efficiently achieve target mat density. This allows field personnel to make decisions concerning cold weather paving and the scheduling of HMA deliveries to the paving site.
While it is no substitute for good judgement and on-the-job observations, MultiCool can help in the planning process and in field decision making.
The app has been recently updated to make time-to-compaction calculations in the field easier. Depending upon mix temperature and air temperature, the time a roller operator has to achieve the desired density can vary significantly from day to day or job to job.
MultiCool V2.0 was developed by Dr. David Timm and Ben Peters of Auburn University with funding from the National Asphalt Pavement Association (NAPA). It can be downloaded for Android devices through the Google Play app store or visit goaspha.lt/multicoolv2 to access the desktop or mobile web version.
MultiCool has been validated in cold (Minnesota) and warm (California and Alabama) climates for typical Superpave mixtures, stone matrix asphalt (SMA) mixes, warm mix asphalt (WMA), reclaimed asphalt pavement (RAP), recycled asphalt shingle (RAS), and ground tire rubber (GTR) mixtures.