In previous versions of IMPACT for Revit, there was a bit of confusion related to the prestressed strands family name when drawing a Prestressed Beam - the prestressed strands family was using the Hollow core strands. 

We are happy to announce that we have changed the default strands family name when drawing a Prestressed beam - it is now using Prestressed beam strand. 

Figure 1 - Prestressed beam strand in a prestressed beam