Use of Phase Change Materials to Prevent Overnight Freezing of Bridge Decks

摘要

This project evaluated a class of polymeric materials that stored and releasedheat energy as a result of phase change in freezing temperatures for use in concrete to prevent overnight freezing of bridge decks. The phase change materials, encapsulated in polyethylene pellets, were either mixed with or installed around the concrete to provide heat energy. Test results showed that the phase change materials decreased the conductivity of concrete slabs which slowed down its warming rate adversely affecting the performance of the phase change materials. Placing the material at the bottom of the concrete slab delayed the cooling of the slab top surface; however, it also slowed down its warming rate which was not desirable.