Abstract
dc:descriptionThe use of fabrics as reinforcement in concrete structures opens up many new applications for composite members. The advantages of this new composite material are a good corrosion resistance with a thin concrete cover and a high effectiveness of the reinforcement by using textiles instead of short cut fibres. Until now, neither the load-bearing performance nor the deformation behaviour has been investigated in detail. Cracks will appear systematically in textile-reinforced concrete because of the low tensile strength of the concrete. The understanding of this cracking process is of crucial importance in calculating the load-bearing capacity, the deformation behaviour and the limiting values in designing for the serviceability. Cracking is determined not only by the stress but also to a considerable extent by the bonding action between the textile reinforcement and the concrete matrix. Modelling the load-bearing behaviour should differentiate between the microscopic bonding behaviour which describes the physical interaction between the raw materials used (fabrics and concrete) and the macroscopic bonding behaviour in order to describe the influence on the load-bearing performance of whole members. The bond behaviour of fabrics embedded in concrete and consisting of multi filament yarns (rovings) differs from that of homogenous materials such as steel. Test results published in the literature as well as own investigations revealed that, for textile reinforced concrete, it has to be distinguished between external and internal bond of the fibres (filaments). The outer filaments that have direct contact to the cement matrix show a good bonding performance. In contrast to this, the inner filaments (core filaments) of a roving transfer forces only by friction, resulting in a less bonding to the surrounding matrix. After cracking, the tensile stress within the cracked cross-section is resisted entirely by the filaments. The distribution in the strain differs because of the difference in bonding behaviour between sleeve and core filaments. The sleeve filaments with the higher bond stiffness need a shorter development length in comparison with core filaments in order to reach the same strain at the crack. In order to examine the load-bearing behaviour of textile-reinforce concrete more in detail, in this theses a lot of tests were performed. The aim of the tests on tensile test specimen and beams was the development of mechanical laws for tension, shear and bending for different concrete types and textile fabrics. The tests showed that using fabrics as reinforcement can increase the load bearing capacity of concrete elements. A high degree of reinforcement causes a high load bearing-capacity. The biggest influence on the load bearing-capacity has the tensile strength of the fabrics itself. Shear tests showed that also the geometry of the cracks, the deflection of the crack edges and the direction of the reinforcement have a significant influence on the shear-capacity. This can be explained with local tension peaks of the textile reinforcement at the crack edges and the destruction of single filaments. Based on known mechanical models in this theses new methods were developed in order to calculate the load bearing-capacity and the deformation behaviour of textile reinforced concrete elements. With theses methods it is possible to determine the load bearing-capacity and the deflection for tension, shear and bending, if the quantity and the mechanical properties of the textile reinforcement is known.
Degree
thesis:*- Grantor dc:publisher
- Lehrstuhl und Inst. für Massivbau [u.a.]
- Year dc:date
- 2005
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Molter, Matthias
- Contributors dc:contributor
-
- Hegger, Josef
Subjects
dc:subject × 10Rights
dc:rights- Statement dc:rights
-
- info:eu-repo/semantics/openAccess
- Language dc:language
- ger
Identifiers
dc:identifier.*- OAI identifier oai:identifier
- oai:publications.rwth-aachen.de:58905