A Drainage System for Mitigating Moisture Damage to Bridge Deck Pavements

Abstract

This study presents the development of a new drainage system that can quickly drain water that has penetrated into bridge deck pavements. The new drainage system is expected to significantly reduce potholes that typically lead to premature failure of pavements. This system can be established by applying a thin drainage layer between the waterproofing layer and top wearing course. The most important factors for this system are to meet satisfactory performance of the waterproofing layer and to develop appropriate construction technique for the thin drainage layer. The drainage layer was formulated with porous asphalt mixtures designed for the max aggregate size of 10 mm, and was validated through various physical and mechanical laboratory tests to confirm its performance characteristics. For the waterproofing layer, methyl methacrylate (MMA) – type material was introduced, and a series of mechanical tests were performed to estimate the applicability of the MMA material for waterproofing. It was observed from the tests that the MMA material satisfied all specification requirements. In addition, to evaluate the field performance of the new drainage system, a field study was conducted on a real bridge. Field performance observations on both the waterproofing and pavement materials indicated that the new drainage system performs much better than traditional methods in draining water that has penetrated into pavement layers.