Here's why:
* Verb: "Barricade" means to block something with a barrier.
* Past Participle: The past participle form is used to form perfect tenses (e.g., "They have barricaded the street") and passive voice (e.g., "The street was barricaded").
So, while "barricade" is a verb, "barricaded" acts as an adjective when describing something that has been blocked, or as part of a verb phrase.