7.7 Repair and Maintenance

Building materials, mainly the conventional ones like concrete, timber, or metals need service repair and maintenance during their life. Concrete, in spite of being the most extensively used construction material, has not proved to be as durable and maintenance free as one would have liked. An increasing number of buildings develop signs of distress within a few years after their construction, mainly when built in locations subject to an aggressive environment. Factors such as design inadequacies, poor workmanship, use of low quality materials, and poor maintenance practices, besides corrosion of reinforcement are the major causes for the rapid deterioration of many structures [279]. Once cracking or other manifestations of deterioration are visible, the concrete is more susceptible to further damage, which may eventually render it unsuitable for further use. Although it is obvious that economic and political considerations will be important in decisions on maintenance and repair, from a technical point of view early maintenance is desirable for maintaining its integrity. Preventive maintenance consisting of regular inspection and restoration of sealed joints, drainage systems, etc., will play an important role in the durability of concrete [280].

The important matter in repair is to establish the nature and severity of the service environment, to properly assess how much degradation has occurred, and to reasonably estimate the intended service life. From these and known relationships of environmental influences on building materials, techniques can be developed to give a repair that will have a reasonable probability of success.

Economic...