STRENGTH AND SERVICEABILITY OF DAMAGED AND REPAIRED CONCRETE STRUCTURES

Abstract

Durability of concrete structures is of great concern at present not only to engineers but to members of the public who use public and office building and own apartments and demand assurances that the buildings are not likely to deteriorate or collapse. Much research has been carried out into the causes of damage to concrete structures particularly corrosion from chlorides. Detailed repair procedures have been developed covering all types of damage and repairing reinforced concrete has become wide spread. However, there is a lack of experimental data regarding effectiveness of repairs and strength of repaired elements. Better methods are also sought to assess the strength and serviceability of damaged and repaired structures. These problems can only be properly assessed through comprehensive test programes: This research programe was set up to study aspects of deterioration and damage of concrete structures in relation to assessment of strength. The programe consists of the following parts: (a) To study causes of deterioration and methods of repair of concrete structures (b) To make some case studies of damage that has occurred and the repairs made to specific structures in Singapore. (c) To test beams, columns and model frames damaged in a variety of ways e.g. specimens with cracks, cover spalled off, area of honeycomb or specimens constructed with weak concrete or under designed. Several specimens with each type of damage are made and repaired using different methods. Test results are compared against sound control specimens. (d) To investigate analytical methods for assessing strength of damaged concrete structures.