Grassy Wharf: a case study in concrete deterioration

The Port of Grassy on King Island (Tasmania) is the Island's main shipping port. It is served by the 6,000-ton Searoad Massey of 94 m length. The marginal wharf at Grassy was built in the early 1970s of conventional reinforced concrete construction on steel piles. By the 1980s, the wharf soffit and substructure showed severe cracking and rust staining with delamination of the slab soffit concrete. This paper outlines an investigation conducted into the problem, the diagnosis of its causes, and the remedial actions considered. It also describes the design of a cathodic protection system, installation of which has commenced. This is believed to be the first full scale cathodic protection system of a reinforced concrete marine structure of its kind in Australia