Meso-mechanical Effect of Track Slab Rebar Corrosion

To explore the effect of rebar corrosion on double-block ballastless track slab concretes, a meso-scale mechanical model of track slab concretes was built to study the mechanical properties and damage modes of the slabs with different rebar diameters, spacing and cover thicknesses, the effect of train and temperature loads on the mechanical property of reinforced concrete track slabs with corrosion was analyzed. The results show that the cracking mode of track slabs induced by rebar corrosion mainly depends on the thickness of rebar cover but rarely relies on the diameter or spacing of rebar. In the event the internal cracks of the slabs connect together, the expansion displacement of rebar increases with the increase of the rebar spacing. When the cover thickness is 60 mm and the rebar spacing is 120 mm, the rebar corrosion displacement of 61.2 μm would result in the internal coalescence cracks. The train load has little effect on the slabs with corrosion crack, and may make the stress on the slabs tend to be uniform. The temperature cooling of 30 °C and the negative temperature gradient may cause the further significant increase of the tension damages of slabs with corrosion, at the same time it may cause the coalescence cracks through along the horizontal and vertical directions of slabs. The temperature rise of 30 °C and the positive temperature gradient barely have effect on the damages of the track slabs with corrosion.