Alkali-Aggregate Reaction and Structural Damage to Concrete. Questo articolo non è disponibile.Alkali-Aggregate Reaction and Structural Damage to Concrete

Since AAR was first identified in 1940, it has been a subject dominated by studies of the mineralogy of AAR-susceptible aggregates, the chemistry of the AAR and related reactions and laboratory tests used to diagnose AAR and predict potential future swelling. Civil and structural engineers have found the literature bewildering and difficult to apply to their immediate requirements of assessing the present and future effects of AAR on the strength, safety and serviceability of plain and reinforced concrete structures.
The book discusses methods that can be used for laboratory destructive and in situ non-destructive testing to assess the effects of AAR, and in-service measurements and load-testing to assess the present and future safety of reinforced concrete structures. Methods of repair and rehabilitation and their long-term success are discussed, as are methods of halting or slowing the progress of AAR. At the same time, the fundamentals of AAR are explained in terms intelligible to the civil and structural engineer who is primarily trained in structural mechanics and design, but also needs to have a basic understanding of the AAR process and its effects on concrete.

Geoffrey Blight completed his Bachelor’s and Master’s degrees in Civil Engineering at the University of the Witwatersrand, Johannesburg, and his PhD in Geotechnical Engineering at the Imperial College of Science and Technology, London, in 1961. The early years of his career were spent at the South African National Building Research Institute, Pretoria, where he was engaged in research on design, operation and safety of mine waste storage facilities, including waste rock dumps and hydraulic fill tailings storage facilities. In 1969 Geoff Blight was appointed to the Chair of Construction Materials in the Department of Civil Engineering at Witwatersrand University. The field of study encompassed geotechnical engineering and concrete technology. In 1978 he was commissioned to study and diagnose the cause of cracking occurring in a series of 15- to 17-year-old reinforced concrete structures supporting the Johannesburg motorway system, and diagnosed the cause as AAR. Since then, he has researched and investigated several cases of deterioration by AAR, and has published widely on the subject. He and his co-author, Mark Alexander, spent a number of years in joint research on AAR and other aspects of the durability of concrete. He was a corresponding member of the committee that produced the British Institution of Structural Engineers’ guides on the structural effects of AAR published in 1989 and 1992 and, since 2002, has been a corresponding member of the RILEM* Technical Committees TC 106 and TC 191 – ARP which have been investigating various aspects of AAR.

Mark Alexander completed his Bachelor’s, Master’s and PhD degrees in Civil Engineering at the University of the Witwatersrand, Johannesburg and lectured in Construction Materials at Witwatersrand University for several years. In 1992 he was appointed to the Chair of Civil Engineering at the University of Cape Town where he has further developed his interests in concrete durability, including repair and rehabilitation of deteriorated concrete structures. He has published extensively and is active in international scientific circles. He co-authored the book, Aggregates in Concrete published by Taylor and Francis in 2005. He is currently Vice President of RILEM* and is scheduled to assume the RILEM Presidency in 2012.

* Reunion Internationale des Laboratoires et Experts des Materiaux.