An ice composite body (10) has an inner ice core (11) and a protective outer armour shell (12). The outer armour shell (12) consists of a base section (13), side sections (14) and a separate top section (15), which is free to move vertically between the side sections (14). The inner ice core (11) is maintained in a frozen condition in use by refrigeration pipes (21), which are located at various levels therethrough. The inner ice core (11) is built up from thin layers of ice which are frozen one after the other. Following the freezing of each layer of ice the layer is rolled using a roller apparatus which provides a roller pressure in the range of 3.5 to 8 Newtons / mm<2>. The ice composite body (10) can be used in warm or cool waters for applications such as bridges, breakwaters, causeways, pontoons, artificial islands, dams, tidal barrages, wave power barrages, harbour walls, wind power farms or aircraft runways.