ブックタイトル「煉瓦造建造物の保存と修復」英語版

概要

「煉瓦造建造物の保存と修復」英語版

spalling of brick surfaces occurred mostly during periodswhen the temperature rises and extant salts dissolve (in therain season, from June to mid July), rather than when saltaccumulation reaches its peak in the winter months; damageto brick surfaces from spalling is concentrated in the monthsfrom winter to early spring. Based on these observations, anindirect preventive approach of environmental control wasproposed where black curtains were installed at the entranceto keep the temperature inside stable as much as possible(photo 18, 19) (Kuchitsu 2005, p11).５．A Conclusion on Restoration of BrickMasonry Cultural Property StructuresIn reinforcement and restoration of brick masonry culturalproperties, it is necessary to assure safety following thecurrent laws and codes. At the same time, for maintainingauthenticity, minimum intervention with consideration toreversibility is essential. Looking back at the history of howthis issue has been handled, in the early days, reinforcementwas limited to the use of reinforced concrete. In 1981 (Showa56) for the first time at Doshisha University Shoeikan,steel-frame reinforcement was adopted, which inducedtechnological development in a variety of reinforcementmethods. Among these procedures, the use of reinforcedconcrete seems to have not been highly evaluated inthe following stages of technical development, but theconservators then had based their decisions on rationalideas. In later years, in 1990 at the Former KanazawaArmory Warehouses, reinforcement with stainless steelpins was employed fn 8 , while at Former Yamagata PrefectureAssembly Hall restored in the same year, reinforcementwith exterior buttresses was adopted for preserving theinterior finishes. In the latter was seen the first use of resinanchoring for structural reinforcement. Resin anchorscame to be used more widely as boring techniques wereadvanced and the same boring procedures were applied toreinforcement with pre-stressed steel bars. Other methodssuch as reinforcement with aramid rods (2013 FormerShimonoseki British Consulate and 2015 Chateau KamiyaOld Winery Facility) or seismic isolation (2004 Tokyo StationMarunouchi Main Building, Keio University Library presentlybeing restored, and Former Nagasaki British Consulate) havebeen adopted for restoration of cultural properties.It is the development of construction technologyincluding techniques for boring holes in brick walls orseismic isolation systems that supports these reinforcementmethods. However, on the other hand, problems regardingtreatment of patented technology and rising costshave emerged. Also, although there have actually beendevelopment in reinforcement techniques, when we focuson the aspect of reversibility or minimum intervention, thereare merits and demerits in each of these methods. Therefore,even though there are now a number of options availablefor reinforcement, a definite solution has not yet beendiscovered.Regarding repairs, a case in which past restoration workwas reviewed at Chateau Kamiya Old Winery Facility wasintroduced. Here, traces of earlier crack repairs with resinwere surveyed to understand the issues of the current stateand it was decided to repair with grout and aramid.In issues concerning physical properties of brick suchas damage related to salts and freeze-thaw, in order tocontrol water penetration due to rainfall on exterior wallsor moisture absorption from the foundation, there werecases where a coating was applied to the exterior wall or amoisture-proofing barrier was installed (as at 2009 FormerTemiya Railway Facilities Shed No. 3). On the other hand, Ata tunnel of Former Usui Pass Railway Facilities, the processof deterioration was carefully observed and a simple buteffective method of hanging a black curtain to preventsudden changes in temperature was devised.In the future, there probably will be technologicalinnovations for reinforcement and repairing of masonryphoto 18 Tunnel of the Former Usui Pass Railway Facilities photo 19Experiment for improved environmental control in the tunnel30Chapter 3Restoration of Brick Masonry Cultural Property Structures