[Gameplay] Warmog's Armor Passive Not Activating

Was playing Volibear on ARAM and my build ended up equaling 3000 Hp exact. Warmog's armor passive did not active. I spent 2 hours now trying to record it, but Open Broadcast is not being user friendly at the moment, Sorry.

My items were as follows: Warmong's Armor Randuin's Omen Ruby Crystal

Volibear at Level 13

Runes: 9 Attack Speed Marks 9 Armor Seals 5 Magic Resist Glyphs 4 Scaling Magic Resist Glyphs 3 Attack Damage Quintessence

Masteries: 9 Offense: 4 Fury - 3 Brute Force - 1 Martial Mastery - 1 Expose Weakness 21 Defense: 2 Block - 1 Unyielding - 2 Recovery - 3 Veteran's Scars - 1 Juggernaut - 2 Hardiness - 1 Resistance - 3 Perseverance - 1 Adaptive Armor - 4 Enchanted Armor - 1 Legendary Guardian