During the 2000s, the concept of cathodic protection (CP) shielding was first raised in open literature and remains debated between coatings professionals. The mechanism of CP shielding, and its understanding continue to be studied for different coatings with different approaches and using various techniques. From the CP shielding factors to the assessment methods, the published literature merits a deep analysis to capture the established knowledge and identify the research gaps to further tackle the issue for reliable coated buried structures. A holistic approach to this topic seems necessary where coatings ageing, cathodic protection, electrochemistry, and transport processes should be considered. In the first part of the present review, the recent works related to the understanding of CP shielding, coatings properties were considered before discussing the mechanisms involved underneath coatings. Transport phenomena and their relationship with cathodic protection performance in the presence of chemical and microbiological processes are discussed in the second part. Finally, CP shielding assessment methods and modeling works are presented and discussed from different perspectives. 

The objective of the project was to develop recommendations for how sprinkler systems in churches and other culturally valuable buildings can be made with technical solutions that are long-term sustainable and that involve reasonable operating and maintenance needs. The starting point is that the latest edition of accepted standards (SS-EN 12845) and rules for sprinkler systems (SBF 120) as well as for fire alarm systems (SBF 110) should be used. But here it should be recognized that buildings and other conditions are unique, and the individual case may require decisions and technical solutions that are difficult to generalize or predict.

The need for sprinkler systems needs to be based on a methodical evaluation of the fire protection to assess the building's protection value, followed by a detailed examination of the existing fire protection measures and an analysis of possible ignition sources and fire scenarios, how quickly a fire can be detected and what possibilities exist to limit or extinguish the fire at an early stage (by staff or local residents) and the rescue service's response options. For each scenario, an assessment of potential personal and property damage is then made. This analysis should result in an assessment of whether the damage can be considered acceptable or whether additional protective measures, for example an automatic sprinkler system, is desired.

If the sprinkler system is installed as a particular ambition to improve property protection, the property owner is the claimant. The property owner can choose to set higher or lower requirements than the recommendations given in SS-EN 12845 and SBF 120. If the sprinkler system is installed to meet authority requirements (often personal safety requirements), then the relevant legislation also constitutes a requirement. Legislation often specifies SS-EN 12845 or SBF 120 as an acceptable level and any deviations from these need to be verified by the property owner as part of an analytical design or reasonableness assessment. The property owner should also always ensure that the building is insurable and negotiate relevant insurance terms linked to the purpose of the sprinkler system.

The first step in planning a sprinkler system is to establish a design basis, where the purpose and overall functions of the system are established. It then forms the basis for the detailed sprinkler system design and the final delivery inspection. It is normally necessary to have a collaboration between the fire protection consultant, antiquarian expert, conservator, building designer and sprinkler designer already at this stage, who jointly draw up the principal specification.

Based on this specification, the detailed design should be done by a certified sprinkler engineer with extensive experience in designing sprinkler systems for similar facilities. Contact should be made with claimants, building antiques and the county administration at an early stage. Before planning, contact should also be made with the relevant municipality's waterworks department and an analysis of the water quality in the public water supply network should be carried out.

The concrete technical recommendations from the project that should be followed are, among other things, that a full capacity tank is built if connection to the public water supply network is not possible, wet-pipe systems should use stainless steel and/or copper pipes alternatively steel pipes with proper wall thickness, that antifreeze should not be used, that visible pipes with discreet placing and painting are preferable to concealed arrangement of pipes and that sprinklers with fusible links or cylindrical thermal elements should be used instead of sprinklers with glass bulbs. If there is a risk of freezing, the sprinkler system should be designed as either a dry-pipe system or possibly a pre-action system or a wet-pipe system with insulated pipes and electrical trace heating. For spaces where an unintentional sprinkler activation or freezing of any remaining water can cause water damage, a pre-action system of Type A ("double interlock") should be used. Joining of pipes should be done using proven techniques such as welding (undertaken outside the building), threading or with flange joints where an unwanted outflow of water can have major consequences. Installation of sprinklers in unfurnished attic spaces should be carried out according to the recommendations in NFPA 13, alternatively using special approved attic sprinklers. Building engineering measures to prevent water damage due to intentional or unintentional sprinkler activations should be considered.

Results from the international cooperative programme on effects on materials including historic and cultural monuments are presented from the period 1987-2014 and include pollution data (SO2, NO2, O3, HNO3 and PM10), corrosion data (carbon steel, weathering steel, zinc, copper, aluminium and limestone) and data on the soiling of modern glass for nineteen industrial, urban and rural test sites in Europe. Both one-year and four-year corrosion data are presented. Corrosion and pollution have decreased significantly and a shift in the magnitude is generally observed around 1997: from a sharp decrease to a more modest decrease or to a constant level without any decrease. SO2 levels, carbon steel and copper corrosion have decreased even after 1997, which is more pronounced in urban areas, while corrosion of the other materials shows no decrease after 1997, when looking at one-year values. When looking at four-year values, however, there is a significant decrease after 1997 for zinc, which is not evident when looking at the one-year values. This paper also presents results on corrosion kinetics by comparison of one- and four-year values. For carbon steel and copper, kinetics is relatively independent of sites while other materials, especially zinc, show substantial variation in kinetics for the first four years, which needs to be considered when producing new and possibly improved models for corrosion. © 2017 by the authors.

MiniCan is a field test designed to highlight certain aspects of corrosion in a KBS-3 type repository for spent nuclear fuel. Five experimental packages containing miniature copper-cast iron canisters were installed in the Äspö Hard Rock Laboratory in 2006. Three packages have been retrieved, MiniCan 3 in 2011 and MiniCan 4 and 5 in 2015. The packages were examined regarding surface chemistry, microbiology and corrosion of copper and iron. The main difference in design between the retrieved packages was the presence and density of bentonite clay. Black deposits of sulphides were visually noted during dismantling of both MiniCan 3 (low density clay) and MiniCan 5 (no clay), but not in MiniCan 4 (high density clay). Extensive corrosion of cast iron specimens was observed in all three packages, with local attacks corresponding to the loss of hundreds of µm/y. Sulphate reducing bacteria (SRB) were found to be present in ground water, in bentonite clay and on surfaces of various specimens of iron and copper, and it is suggested that the SRB activity had a pronounced influence on the corrosion observed. Copper surfaces display a roughness at the µm level and the integrated corrosion rate of copper mass-loss specimens was generally low. This paper is part of a supplement on the 6th International Workshop on Long-Term Prediction of Corrosion Damage in Nuclear Waste Systems. © 2017 The Author(s).