The whole idea with reinforced concrete is that concrete has thermal expansion very similar to that of steel, thus both steel rebars and the concrete that enclo

The whole idea with reinforced concrete is that concrete has thermal expansion very similar to that of steel, thus both steel rebars and the concrete that encloses them move in the same manner. A rule of the thumb with bridges is that the movements (thermal expansion/contraction + elongation or contraction due to loads + in case of pre-stressed concrete fluage/creep) is in the range of 6-9 mm every 10 m. Expansion joints on (long) continuous beam bridges can thus need to have very large displacement, up to 1,200-1,400 mm are relatively common.