A gas turbine duct casing, in particular for an aircraft engine, is disclosed. The duct casing has a first wall segment and a second wall segment which is connected to the first wall segment by a clamp arrangement. The clamp arrangement has at least one clamp and one bolt which passes through a hole in the clamp and is screwed to a nut on a side of the clamp facing away from the wall segments. The nut braces at least one first leg of the clamp against the first wall segment, in particular by an intermediate element, and braces at least one second leg of the clamp against the second wall segment. The bolt has a head which is guided in a form-fitting manner in a groove on the outside of the first wall segment facing away from the gas duct.