Just wondering if anyone know if the damage is being blocked before damage reduction or together.
For example if i have -70% received physical damage + physical Damage blocked 40%, when i block an attack would i not receive damage or would i still receive 18% of the damage?

Essentially it's like + Block 40%. but only against physical attacks

Block is like an 'anti-crit' that occasionally occurs when you wear a sheild. It is affected by your STR, and other effects that include it's mention. It affects both physical and magic attacks.

In your case, it increases block against physical by 40pct and would be calculated after the block rate determined from STR.