Materialeigenschaften und Anwendungen von Konstruktionsbetonen modifiziert durch waessrige Kunststoffsysteme

Till to now, the relative practical importance of plastic modified concrete is restricted to its use as a building material for redevelopment and restoration. Polymer modified structural concretes were without significance. The author puts the practical assessment of plastic modified concretes by an extensive investigation of materials on a new basis. The main aspects of investigation are: (a) advantages of plastic modified concretes with respect to tightness and resistance in comparison to conventional concretes; (b) Looking for further properties with respect to the assessment; (c) increase of plant safety or increase of the lifetime of a construction by modification of plastic concrete; (d) economical solution of plastic modified concretes. The author investigates two systems, a styrene-acrylate dispersion and an epoxy resin, consisting of an epoxy resin component and a special hardener. During the experiments, the composition and the amount of plastic was varied in comparison to a reference concrete without addition of plastics. The properties of green concrete and solid concrete can carefully be directed by addition of polymers. Both polymer modified concretes have a softer consistence which increases with increasing amount of plastics. The styrene-acrylate dispersion causes a higher liquefying effect than the epoxy resin. This effect increases with increasing amount of plastics in the concrete. A decrease of the relation water/cement at constant processibility is possible.Polymer addition reduces the concrete strength. No decisive variations of strength could be observed in the range of tensile strength. Only the styrene-acrylate modified concrete shows some increase in strength. Both types of concrete have a sufficient resistance against frost and deicing salt. Plastic modified concretes are more chemical resistant in comparison to non-plastic modified concrete. The chemical resistance depends on the polymer substance, contamination liquid and the amount of plastics added. Due to the addition of plastics, the penetration depths of liquids into the concrete can be reduced. Plastic modified concrete can be used in the range of construction according to environmental production because these substances are a good alternative to steel or concretes with coatings. With addition of plastics, safe and economical concentrations are possible.SIGLEAvailable from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman