Control and repair of bridge deck cracking
Abstract
Bridge deck cracking has been identified as a significant problem that can shorten the lifespan of a bridge. Deck cracking allows water and deicing salts to penetrate the deck, often leading to corrosion of the reinforcement and deck deterioration. Previous research has indicated that these cracks are mainly caused by restrained shrinkage that takes place when the concrete deck is not allowed to shrink freely and develops tensile stresses that exceed its strength. There are two primary objectives of this research program. First, to evaluate crack repair products that can enhance the durability of existing bridge decks. Second, to evaluate design parameters that can effectively control crack widths and mitigate cracking in future construction. To address these objectives, the research program was conducted in two phases. In the first phase, a macrocell corrosion test was conducted on cracked specimens representative of a bridge deck to evaluate the performance of a variety of crack sealers. From the test results, recommendations on both material type and specific repair products are provided. In the second phase, six full-scale concrete deck specimens composite with steel girders were constructed. A crack was pre-formed at midspan to allow evaluation of various reinforcement layouts in controlling crack widths. Test variables included the amount of reinforcement, bar spacing, and bar size. The test results indicate that the steel reinforcement strain is primarily controlled by the reinforcement ratio. Recommendations are provided regarding the amount of reinforcement required to optimally control crack widths and improve the durability of bridge decks.
Degree
M.S.C.E.
Advisors
Frosch, Purdue University.
Subject Area
Civil engineering
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