EXPERIMENTAL STUDY ON THE EFFECT OF AN EPOXY ASPHALT CONCRETE PAVEMENT ON AN ORTHOTROPIC STEEL DECK

The steel orthotropic deck was used in the steel box girder of a suspension bridge. Four types of fatigue cracks were discovered at some connections of the orthotropic deck during service. Subsequently the pavement on the deck was replaced with epoxy asphalt concrete. To analyze the effect of the new pavement on the fatigue sensitive regions, a finite element model was established and field bridge tests were conducted at three states, namely, original pavement, surfacing, and new pavement. The test lasted for 6 years under the new pavement state. The stress and deformation of the fatigue sensitive regions were measured. The fatigue life improvement was analyzed considering the temperature based on the measured data. The results show that the epoxy asphalt concrete pavement was in a stable working state during the test period, that the stress improvement effects in the fatigue sensitive regions 1 to 4 were 80%, 14%, 32%, 46% in a low temperature environment, respectively. The stresses of the four fatigue sensitive regions were linearly correlated with the temperature, and the linear ratios are −4.00, 0.64, 1.89, 1.91, respectively. After normalizing the measured stress by the average annual temperature, the fatigue life was improved by 2.95 times in region 1, and by 1.64 times in region 4. The fatigue lives in regions 2 and 3 were not improved obviously, and the cracking probabilities of regions 2 and 3 were still high in a high temperature environment.