Remaining Fatigue Life Assessment of Damaged RC Decks -Data Assimilation of Multi-scale Model and Site Inspection

Yasushi Tanaka, Yuya Takahashi, Koichi Maekawa

Journal of Advanced Concrete Technology, 15, 328-3457, 2017

For estimating remaining fatigue life of RC bridge decks subjected to traveling wheel-type loads, presented is the data assimilation procedure, i.e., coupled life-span simulation with inspection data at site. Multi-scale analysis with hygro-mechanistic models is used for the platform of data assimilation on which the visual inspection of cracking on the members’ surfaces and the acoustic emission (AE) tomography are numerically integrated. For verification, the wheel running load experiments of slabs were conducted with continuous data acquisition of both crack patterns and the acoustic emission data over the life till failure. Visually inspected cracks are converted to space-averaged strains, based on which the internal strains and damage fields are re-produced by numerical predictor-corrector cycles. The 3D field of elastic wave identified by AE tomography is also converted to the fracture parameter of concrete. Although no information on cracking is available, the proposed assimilation method successfully reproduces most probable internal cracks over the volume of analysis domains, and the remaining life of the deck slabs inspected was successfully estimated.

Conventional design of reinforced concrete structures is not conservative and hence service life is too short in many cases. The approach described in this contribution may help to reach longer service life in the future.?(Prof. F. H. Wittmann)