ABSTRACT
After all, concrete will need repair, locally if maintained well and generally if users do not attend to that. Repair and rehabilitation of deteriorated concrete is an art as well as science. The repair engineer must have the imagination to select and adapt any of several repair techniques to fix the existing defect (Soudki, 2001). Concrete repair requires a range of materials with different physical and chemical properties and application techniques. Compatibility with the original construction material (called the substrate), structural considerations and ease of use in a wide variety of situations are all crucial. Despite these accepted principles, many architects and engineers design rehabilitation projects without sufficient knowledge of the materials they specify. They often do not appreciate the meaning and importance of compatibility between repair materials and the substrate. It is unclear whether most standard tests are representative of field conditions, yet they are often used to determine durability criteria for field use. The development of performance standards has not kept pace with the development of materials, primarily because of a lack of supporting
1 INTRODUCTION
Modern concrete is a very durable construction material and, if properly proportioned and placed will give very long service under normal conditions. Many reclamation concrete structures, however, were constructed using early concrete technology, and they have already provided well over 50 years of service under harsh conditions. Such concrete must be inspected regularly to ensure that it is receiving the maintenance necessary to retain serviceability. Managers and foremen of operation and maintenance crews must understand that, with respect to concrete, there is no such thing as economical deferred maintenance. Failure to promptly provide the proper necessary maintenance will simply result in very expensive repairs or replacement of otherwise useful structures (Glenn Smoak, 2002).
