Union members at the US Giant Cement plant in South Carolina, shut down equipment, walked off the job Friday night and began picketing the site. Union members have been working without a contract since April 2003 after rejecting a deal the company called its final offer. The union met with management Friday afternoon but voted to strike, said Richard K. Thomas, international representative for the United Steel Workers. Thomas has said key issues are the company wants employees to contribute to health insurance premiums for the first time and the union wants a change in how pensions are distributed for new employees.