we too have a Dorema awning.Hard standings are a pain when it comes to putting up the awning. We bought heavy duty storm pegs,almost 8mm in diameter and have a external thread on it's length. Not cheap about 80p each but very effective. Also I don,t know if you have the same model awning as we have(Cardinal) but you may have loops on the front face of the material just below the windows, I suggest you buy some guy line and make use of these as we used them at the CC site at Wirral country Park in October when a heavy wind set in from the Dee and the use of these extra points helped to keep the awning solid to the floor by using the heavy duty storm pegs.
Hope this Helps