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

3. Present issues and preventivemeasures3.1. IntroductionIn Section 3, general preventive methods taken today willbe given for cases of deterioration and damage explained inSection 2, together with residing issues.3.2. Preventive measures? Prevention of water infiltrationOne method for environmental improvement forcontrolling water ingress was employed at Former TemiyaRailway Facilities / Engine Shed where a waterproofingbarrier was installed; this will be introduced in Section 5.However, in many brick masonry structures, brickreplacement or relaying of bricks is performed withouteffective methods taken for water ingress which wouldhave damaging effects on masonry structures. After awhile, the same form of deterioration will be repeated.? On use of water repellantAlthough water repellant is most times applied as apart of the restoration process, some substances in theagent may remain in the wall fn 7 . Therefore, there arepossibilities of repeated application inducing a differenttype of damage than that due to water penetration.For example, the applied water repellant agent maybe found to be not appropriate for the brick material,leading to whitening of the wall surface (photo 3-1).Also, there are cases where salt damage and freeze-thawdamage occurred around the boundary on walls that wereimpregnated with water repellant and those that weren’t,resulting in deteriorating surfaces (photos 3-2, 3-3) fn 8 .? Methods for repairing deteriorated brickVarious methods have been taken for repairingdeteriorated brick, according to the condition and areaof damage. Representative methods are as follows.photo 3-1 Whitening of wall surface due to application of water repellant（inside white lines）photo 3-2 Repeated damage on the interface on which water repellant hasbeen appliedphoto 3-3 Water repellant has been applied on the material aroundventilation opening, whose interface has seen repeated powdering problems.1 ReplacementDeteriorated bricks are replaced individually fn 9 .2 Brickwork reconstructionAn area of brickwork affected by deteriorationand damage is disassembled for reconstruction.3 PatchingThere are two methods for attaching bricks: entirebricks can be attached or bricks can be patched only inthe damaged areas.4 Infill with synthetic resinThis is a method of filling in spaces of lost parts of bricksurfaces or whole bricks with synthetic resin mixed withpowdered brick to replicate the original composition.From the surveys undertaken, it became clearthat there were no standards for judgment of whichmethod to take or areas to be restored, resulting invariances in how each restoration project is handled.? Issues in brick repair1 Problems regarding brick replacement and reconstructionThere are cases of bricks being replaced for cosmeticreasons, where there is little fear of their falling.Because whole brick units are replaced, new bricks willbe necessary. However, even if these bricks were to bespecially made, it is not easy to precisely match the colorand texture of the fired surface and dimensions of theoriginal bricks. Such changes make it very difficult tomaintain the significance of masonry technology as hasbeen described in Chapter 2 of this report (photo 3-4).88Chapter 6A Collection of Case Studies of Preservation and Restoration of Brick Masonry Structures