The use of synthetic resins on concrete bridge decks

The study of road pavements on concrete bridge decks is of interest especially for the renovation of existing bridges. This work investigates the physical-mechanical behaviour of synthetic epoxy resins that can be used as an impermeable wearing course on concrete viaducts and bridges. The aim of the study is to obtain a mix with better performances than those currently used, in terms of resistance to permanent deformations and fatigue. The experiments were therefore focussed on tests that could simulate these damage mechanisms, also comparing the performances of the epoxy resin-based mixes with those of a traditional asphalt. After conducting a mix design study for the resin-aggregate mixes, the surface texture (with the skid tester and sand patch method), permanent deformations (rutting tests) and fatigue resistance (tests of cyclical loadings at set frequency) were measured. The synthetic mortar adherence to the concrete support was also studied. The aggregates used were non-conventional materials, chosen on the basis of their mechanical characteristics. In all the tests the bridge deck was simulated by concrete slabs or beams (depending on the type of test) reinforced with steel fibres dispersed in the cement matrix. To verify the adhesion of the resin-aggregate mix to the support, wet, pre-cracked and dry specimens were prepared, as well as traditional specimens for comparison. The results indicate that the mix of resin and aggregates has good resistance to permanent deformation and some types of mixes have surface texture values that, in terms of skid tester and sand patch, are optimal compared to traditional asphalt. As regards fatigue resistance, the material (subjected to 150,000 cycles at 10 Hz frequency and 150 strain deformation) maintained a good performance, being resistant to cracking and maintaining adherence to the support, even if this was wet or pre-cracked.