How do you get the barbell down/off the floor when doing really heavy deadlifts?

So my gym is quite small and has a small weight section. We only have 2 barbells, one in a squat rack and one for the bench press. When I do my deadlifts I just use the bar from the bench press and put it on the floor.

I can dead 70kg now but I find it really quite hard to put back on the rack, last time I didn't even think I was going to be able to put it back on! So I am just wondering how people do this when they get to really heavy deadlifts, because it will be impossible to pick up like that. My deads will start to plateau early because it will become just too heavy for me to rack with my arms.