A concrete mixing truck is seen through a hole in a wall at Lafarge concrete production plant in Pantin, outside Paris, April 7, 2014. Switzerland's Holcim unveiled a deal to buy France's Lafarge on Monday to create the world's biggest cement maker, with $44 billion of annual sales, and spark a raft of asset sales worldwide to steer it through antitrust rules. REUTERS/Christian Hartmann (FRANCE - Tags: BUSINESS CONSTRUCTION)