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

fn 205-2. Standard for judging replacement of bricks【Case 1：Nirayama Reverberatory Furnaces】Name：Nirayama Reverberatory FurnacesConstruction year：Ansei 4（1857）Structure：Brick masonryArea 3,016m2Location：268 Naka, Izunokini City, ShizuokaProprietor：Japanese government（Ministry ofEducation, Culture, Sports, Scienceand Technology）Administrator：Izunokini CityDesignation/Registration（date）：Historic Site（1922.03.08）Investigation period2013, 2015, 2017? Restoration planningThe bricks used at the Nirayama Reverberatory Furnaces were manufactured at the endof Edo period and is highly valuable as an example embodying the historic transition ofbricks in Japan (photo 5-9). This reverberatory furnace has in the past undergone threelarge-scale restorations (in 1909 [Meiji 42], 1957 [Showa 32], 1985 to 1988 [Showa 60-63]) and damaged original members have been replaced each time fn 21。However, in recent years, further deterioration in the brickwork was discovered (photo5-8) and in order to make repairs with the minimum replacement of bricks, detailed surveyswere executed on the structure’s degree of damage.? Outline of preventive measuresFor each of the more than 20 thousand bricks in the structure, individual digital clinicalrecords were created (figure 5-2). The items recorded are as follows fn 22 : 1 location of brick,2 period, 3 impression mark, 4 writings at the time of construction or restoration, 5degree of surface deterioration (light, moderate, severe, none), 6 presence of minor cracks,7 presence of large cracks, 8 joint thinning, 9 soiling, and 10 presence of plaster finish.fn 23? Degree of deteriorationThe degree of deterioration of each brick was judged according to the following standards.deterioration (light)：loss of section is only on the surfacedeterioration (moderate)：loss of section is less than 1/2deterioration (severe).：loss of section is more than 1/2minor crackslarge cracks：cracks are seen on the brick surface：brick is split by larger cracksthinning of joints：pointing has been washed out creating gaps between brickssoiling：soiling on the brick surface mainly due to rainwaterplaster remaining：substantial plaster finish remains on the brick surfaceplaster-like trace remaining：traces that appear to be plaster finish remain on the brick surfaceno remaining plaster? Overview：no plaster finish remains on the brick surfaceDetailed observation of changes to the brickwork becomes possible through themanagement of individual bricks. Also, the progress of deterioration can be reflected on therestoration to minimize brick replacement.photo 5-8 Condition of deterioratedbrick wall surfacephoto 5-9 Current condition of the original brick（Circlular marks impressedon the original bricks are shown within the red lines.)figure 5-2 Digital clinical record of bricks of Nirayama ReverberatoryFurnaces（figure provided by：World Heritage Section, Izunokuni CIty）96Chapter 6A Collection of Case Studies of Preservation and Restoration of Brick Masonry Structures