Evaluation of Cracking Performance of Bridge Decks With And Without Overlays and With and Without Fibers

Abstract

Ninety-three spans on 19 bridges, constructed between 2013 and 2020, were surveyed for cracks. The decks were constructed on either steel or prestressed concrete girders. The spans were constructed with or without overlays, some of which used silica fume as a partial replacement for portland cement, with or without nonmetallic fibers, or with monolithic decks with or without nonmetallic fibers. Of the six bridges with conventional overlays (without silica fume), four contained fibers. All nine of the bridges with silica fume overlays had fibers. Of the four monolithic decks, two had spans with fibers, one did not have fibers, and one had two surveyed units (each with three spans) with fibers and four surveyed units without fibers. The bridge superstructures had from two to seven spans with lengths ranging from 147 to 808 ft (44.9 to 246. m), and roadways with widths ranging from 32 to 70.5 ft (9.8 to 21.5 m). The surveys revealed that decks with concrete overlays crack more than monolithic decks for decks on both steel and prestressed concrete superstructures. Decks with cement paste contents less than 27% of the concrete volume cracked less than decks with a higher volumes of cement paste. More generally, good construction practices are needed for low-cracking decks, and with poor construction practices, even decks with a low paste content, with or without fibers, can exhibit high cracking.