Influence of slab void on cement concrete pavement deformation under dynamic loading

In order to illuminate the effect of slab void on deformation under dynamic loading, this paper established a three-dimensional finite element model through the employment of moving loading and hiding element to simulate the dynamic loading of vehicle action and the void, respectively. The deformation and stress-strain of slabs were compared before and after the void. The result shows that even though the joins' loading transfer capability works well, deformations of slab on joins grow greatly with the increasing void. The deformation and stress on corners of two-side slab void are aggrandized remarkably, and the maximum equivalent stress gets to 0.87 Mpa, which is 2.35 times of those on un-void slab. This worsens the mechanical state of slabs and accelerates the fatigue failure. The deformation difference is unconspicuous because of the deformations on two adjacent slabs growing together due to the good loading transfer capability, thus two-sides slab voids are more difficult to be found by observing deformation difference. Therefore it is necessary to put forward a method to detect the position of void exactly, and then pour slurry on slabs in time to improve the slab's stress state and prolong the service life of concrete road.