Thermosetting, thermally-expandable molded body with long fibers or fibrous structures

Thermosetting, thermally-expandable molded body comprising: a) at least one reactive resin, b) at least one hardener and / or accelerator) fibers or fiber structures, where d1) be c at least one blowing agent, d) the fibers as individual fibers having a length in the have the range of 6.5 to 25 mm, or d2) the fibers as a two-dimensional sheet with an extent in the range of (2 to 25 mm) x (2 to 25 mm), preferably in the range of (6.5 to 25mm) x (6.5 to 25 mm), or d3) as a three-dimensional spatial structure present.