Innovative concrete mixtures are currently under development, entitled "Extending Construction Season, for Concreting Applications under Cold Weather Conditions." This is a pool fund project and consists of three phases: Phase I demonstrated the practicality of antifreeze admixtures for concrete and delivered the tools to design, mix, place, and cure concrete in below-freezing weather (supported by 10 northern States, completed in October 2003). Phase II defined the effect of phase I antifreeze formation on the freeze-thaw durability of concrete (supported by 10 northern States, completed May 1, 2006). Phase III will be conducted in fiscal year 2008; the objective is to develop guidance for designing admixture dosages for concrete to allow one to design a full range of admixture dosages to fit the typically varying weather conditions experienced by any job location. The primary objective of this proposed effort is to develop a new version of high-performance paving software that uses calorimetry information and reports the temperature development and concrete strength gain for use in cold weather concrete paving applications. It would also include a feature to download weather data from the National Weather Service Web site automatically. The modified version of high-performance paving will be tested under laboratory-controlled conditions to properly validate the high-performance paving predictions in cold weather against field data. Modifying high-performance paving to report the temperature development in the concrete would allow users to evaluate the temperature curing regime for these concrete mixtures under cold weather conditions and thus evaluate strength gain. It is anticipated that in addition to calorimetry testing, additional thermal properties of the concrete materials will be required for an accurate concrete temperature prediction (such as thermal conductivity and specific heat, which are currently hard coded in high-performance paving for ease of use). It is proposed to include these thermal properties as advanced inputs in the research grade version of the high-performance paving software.