pound up

To strike or hammer something repeatedly and forcefully to break it apart into many pieces. A noun or pronoun can be used between "pound" and "up." He pounded up the pills in the mortar until they were a fine white powder. Protesters tore down the controversial statue and began pounding it up with sledgehammers.

pound something up

to break something up by pounding. Pound the crackers up into crumbs and use them to coat the chicken before you fry it. Pound up the crackers and put the crumbs in a jar.