TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 425: Waterproofing Membranes for Concrete Bridge Decks documents information on materials, specification requirements, design details, application methods, system performance, and costs of waterproofing membranes used on new and existing bridge decks since 1995.

This synthesis will be of interest to research, specifications, materials, design, and construction engineers; contract and specification administrators; agency project managers and staff; and concrete bridge deck construction contractors. This synthesis describes the state of the practice with respect to the development and present status of waterproofing membranes for concrete bridge decks. This report of the Transportation Research Board describes the use of waterproofing systems applied to new bridge decks and the rehabilitation of deteriorated concrete bridge decks. In addition, this synthesis describes current practice with regard to methods for assessing the effectiveness of membranes, criteria for use, installation practices, and factors that affect the performance of waterproofing systems in new construction and rehabilitation. Suggestions for future research are also included.

This report documents and presents the results of a comprehensive assessment of the protective capabilities of all bridge deck waterproofing membranes known to be available when the project started (1970). An extensive program of laboratory testing supplemented by a limited program of field study led to the selection from an original group of 147 systems, five that appeared most promising for more intensive field evaluation. Materials and construction specifications were prepared for the five systems, in addition to an experimental plan for the field evaluation. The new work is being under taken as a second phase of the study.

Architects, specifiers, contractors, and manufacturers in the waterproof industry cover the basics (including cathodic protection terminology, systems, and history), problem-solving in the field and in the lab, and perceived problem areas and proposed solutions. From the symposium of the same name h