Designing concrete with short service life utilising thaumasite

Abstract Concrete anchors for detectors used in electromagnetic surveys of subsea oil resources should be made with a short service life so that they will disintegrate to sludge and gravel after a few months at sea. This is partly because they should not become obstacles for later trawling after fish, but also to refloat the expensive detectors at a later stage if the release mechanism should fail. The immediate solution was to make a concrete recipe consisting of CEM I, anhydrite and limestone that would convert the cementitious binder to non-hydraulic thaumasite when wet. It is demonstrated how sufficient compressive strength was obtained for such mixes for the first few months, after which they disintegrated completely within 6 months in sea water.