Abstract
The most important failure form in buried joint is transverse cracking. Long term serviceability deeply depends on the cracking resistance of joint layer. To decrease effects of bridge deck movement, the grid panel type has not only debonding part between asphalt layer and concrete slab but also honeycomb grid panel in the binder course. The layer reinforcement is indispensable in this kind of buried joint, since stress is easy to relax in a low stiffness state of asphalt mixture. In this paper, it was quantitatively evaluated that layer stiffness increases by embedding the grid panel into asphalt layer. Based on the field measurement, actual rate of strain induced in the buried joint was investigated. Direct tensile tests were carried out to plain mixture specimens and mixture-grid panel composite specimens. From the test results, relaxation modulus of low stiffness condition was estimated by applying the time-temperature superposition principle, and reinforcement effect of grid panel was evaluated.
