The formation of preplanetary bodies is studied in laboratory experiments, especially the growth of decimeter bodies. As these macroscopic bodies are the building blocks for many growth models, it is very important to investigate possible formation processes and the mechanical properties of large dust agglomerates. Here, experimental results on the properties of decimeter-sized dust agglomerates and results of impact experiments at large collision velocities are presented. Fragmentation is a key process to growth at high velocities as energy is dissipated. Growth is observed for velocities up to 56 m/s and impact angles of up to 45°.