Rory Miller (Meditations on Violence) talks about concrete:
If footwork is critical to your style (and I have yet to see one where it isn’t) then footing, the ability to trust your connection to the ground and to efficiently move your body when you press the earth is pretty damn important.Most martial artists practice with good footing as a given. Not always — some take care to play outdoors and on uneven terrain. Some who frequently practice outdoors in all weather learn about slick wet grass and sometimes gripping mud. Knee deep snow. Broken rock. And good footing isn’t always good footing. Almost every judoka I know has broken or dislocated his little toes on soft mats.
Finished concrete with a light layer of dust is slippery. Very slippery if you are wearing good boots.
Finished concrete is also a good reflector. There is an element of hunting or ambush to a lot of fights. Practice in paying attention to shadows and reflections can give you the edge no matter which side of the dynamic you play.
Falling — You learn to fall on stuff that is much softer than concrete. I’m cool with that. With diligent practice ukemi work just fine on concrete. I’ve taken a full flip on asphalt at about 30 mph without a scratch and a full power throw on concrete with a 260 pound man landing on top without a bruise. The skills translate, but mistakes or poor skill has a much higher price when the surface is harder.
Impact tool and pain compliance — the earth is an impact weapon. In my opinion, it’s usually stupid to hit people in the head with your fist. I find it stupid and inefficient to do so if there is a substance much harder than your fist right next to the threat’s head. Wall or floor, driving a head into it probably works better than hitting with your hand. For one thing, you can get the body weight of both people into the strike. For another you can sometimes entrain the threat’s flinch reaction into the force. Someone flinching into a door jamb demonstrates amazing short power.
Rough concrete also hurts quite a lot. There is a huge difference between kneeling on an opponent’s jaw on a mat and kneeling on the same jaw when it is backed by gravel over concrete.
You can see that he has a different perspective from most martial artists:
I trained with a man, one of the best in the world at what he does, who insisted that the ground and pound was the “worst possible scenario.” Probably everyone knows, but just in case- you are on the ground, on your back. The opponent is straddling you and raining down blows to your face. This ‘worst possible’ scenario wouldn’t even make my top ten. Five or six guys kicking would make it worse. A knife would make it worse. Being face down would make it worse. Being on top could be worse if I think I’m in some kind of wrestling match and the threat has decided it’s a knife fight… on and on.
What does this last bit have to do with concrete?
When the backstop is concrete anything that misses has a price to pay. Fully committed, full power, threat can cause his own crippling injury. You just have to make the threat miss. Shifting your pinned hips is usually enough.