Repair/Rehabilitation of Structure

Mr. Aman Khullar, Advanced Technology & Engineering Services, a division of Aimil Ltd.

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A structure, when it is constructed, has generally got a service life. The service life is dependent on the quality, workmanship of the construction and various other factors including materials, components, etc. A building or a structure can exhibit early deterioration signs due to reasons like bad workmanship, lower degree of adherence to the specification of materials and the general guidelines of construction procedures. Other reasons could be harsh service environment to which a structure is exposed due to change in surrounding environment, and physical damage due to fire, explosion or earthquake. These reasons reduce the service life of a building or RCC structure.

Any repair/rehabilitation work can be carried out successfully if the reasons for distresses are known and well established. The reasons for distresses can be determined by Non-Destructive Testing [NDT] and through a detailed visual condition survey of the affected structure.

Visual examination provides valuable information with regard to workmanship, structural serviceability, and material deterioration mechanism. Simple tools and instruments like camera, magnifying glass, binoculars, and gauge for crack width measurement are usually needed.

Crack identification and mapping is taken up for visual condition survey. A crack less than 0.2 mm is not seen by the naked eye and the presence of such invisible cracks does not indicate any distress in the structure. Cracks wider than 0.2 mm are to be located and suitably represented in the drawings.