Method for fitting tensioners to shuttering for pre=stressed concrete structures with bolts inserted into double shell shuttering via locating sleeves

摘要

A method for a secure fitting of tensioners into shuttering for pre-stressed concrete structures has an inner shuttering shell (2) which shapes the concrete and an outer shell (3) to press onto the inner shell. The tensioners are inserted via the outer shells and are guided by metal sleeves (10) under the outer shell and elastomer sleeves (12) between the shells. The conical heads (7) of the tensioners have a lipped rear edge (11) which is trapped by the metal sleeves if the tensioning rods (5) snap during fitting, thereby preventing the tensioners from flying out of the shuttering. The elastomer sleeves prevent concrete 'milk' from seeping out of the mould and guide the tensioners onto the ends of the tensioning rods, to which they are connected by a screw action.