Cracking and failure modes of textile reinforced concrete: Fid-Bau Portal

Cracking and failure modes of textile reinforced concrete

Hegger, J. / Will, N. / Molter, M. / Littwin, R.

The load bearing behaviour of textile-reinforced concrete components is influenced not only by type, quantity and orientation of the textile reinforcement but also by the fine concrete matrix. In particular the bond behaviour of the fibre bundles (rovings) the textile reinforcement is made of, is of great importance. Since the fibres (filaments) within the rovings do not form a homogeneous cross section, a direct analogy to the bond behaviour of steel in reinforced concrete is not possible. In this paper own investigations are presented regarding reinforced tensile test specimens reinforced with glass fibre textiles. In the tests the reinforcement geometry, the slashing product on the fibres, the coating, the fine concrete matrices as well as the fibre orientation were varied. The test series showed that the cross-sectional shape of the rovings, the coating as well as the fibre orientation have a significant influence on the load carrying capacity. In addition to the experimental investigations a numeric model was developed. Comparative calculations showed good agreements with the test results. The performed tests proved that the cross-sectional geometry of textile reinforcement has a significant influence on the load bearing capacity of textile-reinforced concrete. A substantial increase of the fibre effectiveness could also be achieved by a coating / laminating of the textiles. Further investigations with different test series are necessary in order to transfer the obtained results to any textile reinforcement structures. Thereby the development of coatings and laminating systems should be pushed forward, in order to be able to adjust the bond characteristics of textiles. Additionally the use of hybrid yarns is suited for the optimisation of the bond characteristics. Tests with further variations of the ratios of cross-section area to perimeter of the rovings are necessary in order to determine the gradient of the resulting effectiveness of the fibres.