SEDL / STP / STP858-EB / STP34214S

The Willow Island Collapse: A Maturity Case Study

Halvorsen, GT
Associate professor of civil engineering, West Virginia University, Morgantown, WV

Farahmandnia, A
Graduate student, University of Arizona, Tucson, AZ

Pages: 9    Published: Jan 1985

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Abstract

The Willow Island cooling tower collapse of April 1978 is reviewed with respect to the development of concrete maturity during construction. The tower shell was constructed during the fall and spring prior to the collapse. Fall and spring weather conditions were similar with regard to the potential for concrete strength development. However, an increased pace of construction in the spring effectively decreased the maturity of the concrete at the time it was subjected to construction loads. More than half of the concrete lifts placed during the spring construction of the cooling tower shell were supported by concrete with a maturity similar to that of the concrete in Lift 28, which failed during the placement of Lift 29. The collapse might have occurred sooner if several days of rainy weather had not apparently delayed the construction.