Buried joints on steel/concrete composite structures carrying heavy traffic can be prone to premature failure. This is due principally to the inability of the surfacing over the joint to accommodate the relatively large movements due to traffic and thermal variations. Trials were instigated using rubberised, high penetration index and normal asphalt surfacings, with two versions of a buried joint system to bridge the expansion gap. Measurement of the horizontal, vertical and rotational movements were made at all the joints and at selected bearings. The experimental flexible materials were less prone to cracking and spalling than normal asphalt when laid under favourable conditions but when laid in adverse weather and at low temperatures premature cracking and spalling resulted. Restraint at the bearings tends to lower the centre of rotation of the deck ends which increases the horizontal opening at the surface of the expansion joint. (Author/publisher)
Abstract