Laboratory Investigation on the Use of Geocomposites as Waterproofing Systems for Concrete Bridge Decks

Water seepage in cement concrete structures is one of the main sources of degradation, especially for concrete bridge decks. Therefore, the protection of these strategic structures is a crucial task for civil engineers nowadays. In this context, this study focuses on the use of geocomposites as waterproofing systems for concrete bridge decks. Four geocomposites with different characteristics were compared based on a dedicated testing protocol. The influence of the concrete surface condition (dry or wet) as well as the type and dosage of the primer was also studied. Multilayered slabs, composed of cement concrete, primer, geocomposite, and asphalt concrete, were prepared in the laboratory. The proposed testing protocol includes four types of tests, i.e., shear bond tests (SBT) with the Leutner device, pull-off tests, binder bond strength (BBS) tests, and watertightness tests. Most configurations exhibited good shear resistance and adhesion properties. In general, the geocomposite type and the primer dosage had a significant influence on the behavior of the system, whereas the concrete condition and the primer type had no statistically significant effect. In most cases, the weak point of the system was the interface between cement concrete and primer or between primer and geocomposite. Finally, all geocomposites successfully passed the watertightness test. The proposed testing protocol can be useful for producers to design and optimize their products as well as for road agencies to prequalify the product in the laboratory on the basis of clear performance-based technical specifications.