Improvement of textile reinforced concrete by polymer additives: Fid-Bau Portal

Improvement of textile reinforced concrete by polymer additives

Dilthey, U. / Mund, F. / Raupach, M. / Schleser, M. / Walk-Lauffer, B.

The building material concrete is characterised by good workability, robustness, high compressive strength and low costs. The flexural strength amounts approximately only a tenth in comparison to the compressive strength. The forces arising by tensile load can be taken up by an adequate reinforcement. In practice steel works satisfactorily. Alternatively textiles from polymere, carbon or alkali-resistant (AR-) glass fibers can be used as reinforcement. The main advantage is, that they do not require alkaline protection against corrosion resulting in the possibility of low concrete covers. A large research project SFB 532 (financed by the German research foundation DFG) is concerned with the investigation of the innovative composite material textile-reinforced concrete. The presented paper deals with the possibility to improve technical characteristics of textile reinforced concrete by polymeric impregnation of the rovings and by addition of polymers to the fresh concrete. The impregnation of the rovings improved tensile strength and strain at failure due to the improved load transmission between the single filaments. The mechanical properties are adjustable by the type of polymer and the polymeric content. Polymer modified concrete led as well to higher load-bearing capacities of textile reinforced components. The influence of polymer modification of rovings and concrete of textile reinforced concrete had been investigated. The results lead to the following conclusions: Impregnation of rovings with polymers enhances their tensile strength and strain at failure. The bond behaviour of the roving can be adapted to specific tasks by choosing type and presetting the content of polymer. Surface modification of impregnated rovings improves bond between roving and concrete. Tensile strength and strain at failure of concrete is enhanced by polymer modification. Modification of roving and concrete can be combined and the optimal polymer content is specified by the compromise between economic and technical efficiency.