Use of Shrinkage Reducing Admixtures and Lightweight Concrete in Virginia Bridge Decks - 2014

Abstract

Crack surveys were performed on nine bridge decks in Virginia. Five decks were constructed with a shrinkage reducing admixture (SRA), three were constructed with lightweight concrete, and one is used as a control. Seven of the decks surveyed are supported by steel girders and two are supported by prestressed concrete. Of the seven decks supported by steel girders, four contain an SRA, two were constructed with lightweight concrete, and one was constructed with conventional concrete and serves as the control. One SRA and one lightweight deck were supported by prestressed concrete; the SRA deck is supported by a prestressed concrete box beam and the lightweight deck is supported by a prestressed concrete slab. The decks were 5 to 31 months old when the crack surveys were performed. The Virginia bridge decks are compared against low-cracking high performance concrete (LC-HPC) and conventional Kansas Department of Transportation (KDOT) decks in Kansas. The surveys performed in this trip provide a good baseline for future surveys and allow for conclusions about the early performance of the bridge decks. The decks constructed with an SRA are performing better than the decks built with lightweight concrete. Initial surveys suggest that the SRA decks are not performing as well as the LC-HPC decks and that the lightweight decks are not performing as well as either the LC-HPC or control decks in Kansas. Decks with lower paste contents are performing better than decks with higher paste contents.