Worker David Hoyle, 32, pleaded guilty to a charge of theft from his hydraulic jacking specialist employer Bill Boley Ltd at Newcastle Crown Court.
Hoyle from Washington in Tyne & Wear admitted he loaded the eight bridge supports onto a JCB telehandler and then drove them from a building site in Felling where he was working to a scrapyard.
The court granted bail and will sentence Hoyle in early August.