Yuta WADA

Study on the Effectiveness and Optimal Specification of Emulsion Penetration Method for Reusing Residual Cutting Layer of Bridge Surface Pavement

Osamu TAKAHASHI

In Japan, road bridges are generally constructed with an asphalt pavement over concrete slabs. Because water penetration into slabs accelerates deterioration, a waterproof layer is installed at the boundary between the slab and the bridge pavement to prevent water penetration into the slab. This waterproof layer is reinstalled when the pavement is replaced, but if the life of the waterproof layer is longer than that of the pavement, it may be removed before reaching the end of its service life, which is a problem. In bridge face pavement replacement work, the bridge face pavement is first cut with about 20 mm of the bridge face pavement remaining. If this remaining layer can be reinforced to improve impermeability, it can be reused as an impermeable intermediate layer, and in addition to avoiding damage to the waterproofing layer and slab, it can contribute to reducing the construction cost and time required for construction. 
Previous studies have confirmed that asphalt emulsion can be used as an impermeable interlayer by infiltrating the remaining layer. Based on these results, this study examined effective and efficient specifications for the emulsion penetration method. We focused on the physical properties of emulsion, the amount, and the method of application, and discussed the differences in performance that can be achieved by those method. In this study, three types of highly concentrated modified bitumen emulsions with different properties were used, and the effects of the emulsion penetration method on the impermeability of the remaining layer and mechanical properties such as plastic deformation resistance and fracture resistance were evaluated.
The above study was concluded that the emulsion penetration method is most effective and efficient when a standard amount of a high permeability, hard emulsion that is capable of immediate degradation is applied.