For over 20 years, the Saunders station has been experiencing operational problems attributable to excessive concrete distortions, which required expensive maintenance work and extended outages. If left unchecked, such problems can cause fracture of the turbine propellers, as shown in the Moxoto, Brazil, photo. Until 1990, the root cause of these problems was inexplicable, in spite of numerous studies, field investigations and laboratory testing.

In 1991, as a leader of an extensive multi-disciplinary investigation in Ontario Hydro, Dr. Danay was successful in diagnosing the root cause of these problems as alkali-aggregate reactivity (AAR), which caused gradual concrete swelling and interference with the operation of the turbine-generator assemblies.

A new diagnosis methodology, which integrated computer simulations with field and laboratory testing and instrumentation monitoring, was developed and published in 1993 in ACI Concrete International and in 1994 in ACI Materials Journal.

Danay Engineering Ltd.