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

? Cracks・About cracksCracks tend to appear oncorners and around wallopenings due to aging of thematerial, earthquakes, or groundsubsidence. Also, there arevarious types of cracks fromthose that appear on joints orthose forming in places that haveno relation to the joints and runin straight lines as though to splitthe bricks.Cracks can be largely groupedinto those that appear on thesurface, on the wall surface oronly to the depth of a brick unit,and those that penetrate the wallfrom the outside to the inside.・Surface cracksTiled bricks applied as wall finishes tend to form surface cracks, which in turninduce the tile surface to become detached from the substrate or to pop off from thesurface.・Penetrating cracksWhen penetrating cracks form, the masonry structure will lose its integrity andits durability will decrease greatly. Penetrating cracks most likely will appear attimes of earthquakes and when such cracks form, this will lead to further damagethrough aftershocks causing leaning walls and widening of cracks (photo 2-14).Some structures that have experienced penetrating cracks are Chateau Kamiya OldWinery Facilities (Ibaraki Prefecture), Former Nomura Sugar Store Brick Storehouse(Ibaraki Prefecture), and Former Kumamoto Higher Technical School MachineryExperimenting Facilities (Kumamoto Prefecture).photo 2-14 Penetrating cracks caused by the Great East Japan earthquake (March 11, 2011)（black lines：cracks）? Slippagephoto 2-16Brick wall slipped due to penetrating cracksphoto 2-15Slippage of the wall structure・About slippageAt times, slippage of the wall structure occurs in places where penetrating crackshave formed. Slippage tends to appear when the structure is heavily shaken by anearthquake (photos 2-15, 2-16). Cracks form in various places, from around thefoundation up to the pediment or chimney, where large loads are applied by theearthquake tremor. Slippage may times cause failures in fittings and appliances.86Chapter 6A Collection of Case Studies of Preservation and Restoration of Brick Masonry Structures