During the last 15 years, the thaumasite form of sulfate attack (TSA) has been found in over 80 UK field structures and buildings and is particularly prevalent in buried concrete. This form of sulfate attack completely destroys the cementitious binding ability of the concrete by transforming it into a mush. In 1998, the occurrence of several high profile cases in the foundations of UK motorway bridges initiated a rapid pan-industry response, culminating in a report by the UK Government’s Thaumasite Expert Group. A brief account of the Group’s findings, the diagnosis and risk factors needed for TSA and some postulated reasons for its apparent increase in recent years are discussed in this paper.
The Building Research Establishment has carried out extensive research since the early 1990s on the occurrence of TSA in the field and in laboratory concretes and mortars. Prior to this, a few other UK workers had been involved in more fundamental studies of the mineral thaumasite including its structural characterisation and its laboratory synthesis. Once the profile of TSA was raised in 1998, the number of government and industry funded research programmes increased significantly in the UK and the findings from many of these will be presented in this journal. Information gleaned from UK laboratory research is incorporated in the present paper along with the author’s thoughts on a possible reaction mechanism for TSA. 相似文献
