Astec Industries Inc. founder J. Don Brock has stepped down as president of the Chattanooga, US-based company, and Norman Smith, who co-founded the company with Brock, will replace the 73-year-old CEO as president and chief operating officer. The new "decentralised company structure facilitates the development of a strong internal management team," Brock said. Smith, 72, has served as head of the company's asphalt division since 1998. He was president of both Astec Inc. and Heattec Inc, and has been a direc