Title: Waterproofing of Concrete Structures--10 Years of Experience With Spray-Allied PU Elastomers
Author(s): K. Recker
Publication: Symposium Paper
Appears on pages(s): 135-146
Keywords: bridge decks; concretes; humidity; plastics, polymers and resins; roofs; sprayed coatings; temperature; waterproofing; Structural Research
The importance of solvent- and plasticizer-free sprayable PU elastomers in the field of waterproofing of concrete structures has increased considerably over the last 10 years. Due to their excellent mechanical properties, their resistance to hydrolytic and microbial attack and chemical resistance, waterproofing membranes produced from spray-applied PU elastomers have proved to be very successful in many application areas in the building industry. Report deals with the chemical development of the PU system, the optimization of the processing technique, including the methods of preparing the concrete's surface to get good adhesion values and a seamless, watertight elastomeric membrane, the spray process itself, and the recommended machinery. Special attention is given to the influence of environmental conditions, such as temperature and relative humidity, on the mechanical properties and the performance of the waterproofing membrane in service. As the most important field application for spray-applied PU elastomers in Europe, bridge deck waterproofing membranes are discussed with special reference to the requirements set out in the regulations of the German "Bundesministerium fur Verkehr" and the "Bundesanstalt fur Materialprufung." The performance of spray-applied PU elastomers as waterproofing membranes for roofs, terraces, terracing in sports arenas, and car parks is discussed.