BAR SUPPORTS SHALL BE PRECAST MORTAR BLOCK, PLASTIC OR METAL SUPPORTS. MORTAR BLOCKS SHALL BE CONSTRUCTED AND CURED. THE MINIMUM COMPRESSIVE STRENGTH OF MORTAR USED FOR BLOCKS SHALL EQUAL TO THE MINIMUM COMPRESSIVE STRENGTH OF CONCRETE FOR THE STRUCTURE THAT ARE USED IN. MORTAR BLOCK SUPPORTS SHALL BE ATTACHED TO THE SUPPORTED BAR BY MEANS OF 16-GAUGE WIRE CAST IN THE CENTER OF EACH BLOCK