Experimental study on fatigue durability and strengthning effect of bottom thickness increasing method for RC slabs

The bottom thickness increasing method is a rehabilitation work for RC slabs of highway bridges that places reinforcing bar under the existing slabs and sprayed mortar. Expressway bridges can be kept opening even during this rehabilitation work, so that this method has been applied for the bridge slab under heavy traffic condition. This rehabilitation method improves mainly the flexural strength and the shear strength of existing slabs. In order to assess the strengthening effects of this rehabilitation method for RC slabs, this study carried out the fatigue tests of RC beam specimens and the wheel running fatigue tests of real scale slab specimens with this rehabilitation work. As the results of the tests, it was clarified that the fatigue test of RC beam specimen was useful for the assessment of strengthening effects of the rehabilitation method as well as the wheel running fatigue test. As the result of these fatigue tests, it was found that the fatigue durability of RC slab was improved by the bottom thickness increasing work.