Title: Case Studies of Internal Curing of Bridge Decks in the Greater Cleveland Area
Author(s): Norbert Delatte and Dale Crowl
Publication: Symposium Paper
Appears on pages(s): 1-12
Keywords: Bridge decks, cracking, expansive cement concrete, internal curing, lightweight aggregate, lightweight concrete
This paper discusses three different approaches to internal curing of concrete bridge decks. The first approach is the use of moderate to high absorption aggregate, based on field observations of excessive cracking of bridges with low absorption aggregate. The use of lightweight aggregate (LWA) is the second approach to internal curing. The third approach combined LWA with a shrinkage compensating cement (e.g. Type K). Laboratory testing was carried out on the first two approaches to investigate the cracking tendency of different Ohio Department of Transportation (ODOT) concrete mixtures with different levels of aggregate moisture absorption, and with and without the addition of lightweight aggregate (LWA) for internal curing. In May of 2007 in Euclid, Ohio, east of Cleveland, two bridge decks were cast, one using a standard Ohio Department of Transportation deck mixture and one incorporating internal curing. The City of Cleveland also has a major bridge across the Cuyahoga River, the Main Avenue Bridge, with a deck constructed of lightweight aggregate concrete and Type K cement (third approach). This bridge has been in service since 1939 and the new Type K/LWA deck was built during renovations between 1994 and 1997. The deck is still showing excellent performance.