In this Home & Garden video tutorial you will learn how to make a concrete obstacle. Materials required are cement, 1 big receptacle, 1 small plastic receptacle, a cup for measuring, a spatula, 1 mold, WD40, paper towels and protection mask. Wear the mask, spray WD40 on the small receptacle and the mold, and wipe off with paper towel. Pour two cups of cement in the big receptacle, add one cup of water and mix slowly with the spatula. You can add more cement, water and make it to a watery consistency as shown in the video. Then vibrate the receptacle so that the cement mix well. Leave it to dry up for two days. Then, pull the walls of the plastic receptacle to loosen the cement block, remove it and sand it with abrasive stone to make to make it smooth.