Fatigue performance of AASHTO and Ontario design for non-composite reinforced concrete bridge decks.

摘要

Tests were conducted under a concentrated static, stationary pulsating and moving constant wheel-load on 1/3-scale (P-Series) and 1/6.6-scale (B-Series) physical models of concrete bridge decks of a simply supported non-composite 50-ft long bridge with an 8.5-in. thick concrete deck supported on four steel girders spaced at 7 and 10 ft. Three deck designs are studied: (a) AASHTO "orthotropic" steel reinforcement, (b) Ontario "isotropic" steel reinforcement, and (c) "isotropic" minimum steel reinforcement.;The presence of membrane compressive forces (arching action) in the deck enhances its static ultimate strength. Static ultimate strength values for the decks, P;The type of applied fatigue loading has a profound influence on the fatigue behavior of the decks. Under a moving constant wheel-load, the initial two-way deck slab action changes to a one-way slab action as failure is approached. The bridge decks subjected to a stationary pulsating load exhibited a flexural radial cracking, while those under a moving constant wheel-load exhibited a flexural grid-like pattern similar to the grid of the bottom steel layer.;For a given applied fatigue load level, the decks subjected to a stationary pulsating loading regime exhibited higher fatigue life than those subjected to a moving load. Based on an exponential curve fit of the fatigue data in this study (log P/P