So, what’s the difference between terrazzo and polished concrete? The difference between terrazzo and polished concrete is the cement-to-aggregate ratio. That’s probably the biggest difference anyway.
Cementitious terrazzo is minimum 70 percent marble-chip material and 30 percent cement matrix (with a Portland cement binder). This is pretty much the opposite of regular concrete, which is around 70 percent cement (including fly ash or slag) and 30 percent aggregate (sand and rock).
When placed, terrazzo is poured and troweled about 1/2-inch thick over a low-strength concrete bed. It is then ground flat, honed, and sealed with a penetrating solvent-based sealer.