Publikationsserver der RWTH Aachen University
Zur Dauerhaftigkeit polymergetränkter AR-Glas Bewehrungen in Textilbeton
Abstract
dc:descriptionIf concrete is used as a building material the tensile strength of the reinforcement is one of the most important material properties. Traditionally concrete is reinforced with steel rebars. Textile reinforced concrete (TRC) represents a new and innovative building material, in which the reinforced is made out of technical textiles. Technical textiles are made out of AR-glass or carbon. Even the glass is considered to be alkali-resistant, the AR-glass reinforcement shows a certain loss of tensile strength over the live time of a building member. This strength loss can be up to 40% during an exposure time of 50 years. This loss of strength is mainly caused by an alkaline attack of the glass network due to the high alkalinity of the pore solution of concrete. Due to the requirements of the load-bearing capacity as well as the handling during the production of TRC building members, the reinforcement structures used meanwhile are impregnated with polymers. As polymers there are two different kinds used – water-based dispersions, e.g. SBR-dispersions, or reactive coatings, e.g. epoxy resins. The polymer-impregnation cannot only increase the load-bearing capacity but can also decrease the loss of strength of AR-glass. In order to quantify the long term loss of strength of such polymer-impregnated AR-glass reinforcement structures within the presented thesis a prediction model, called the "hull-model", was developed. The model is based on intensive laboratory research, which covers investigations of the single components of TRC (concrete, AR-glass reinforcement and polymers) as well as the compound material. Based on these laboratory investigations the deterioration mechanisms, which lead to a reduction of the tensile strength, could be identified. The physical as well as chemical processes, which lead to an decrease of the tensile strength, represent the basics of the model. The parameters of the model can all be determined by (comparatively simple) laboratory investigations. One of the main parameters, which affect the long-term loss of strength, is the diffusion coefficient of the polymer used to impregnated the AR-glass. In general the polymer-impregnation with epoxy resin leads to a reduction of the long-term loss of strength by the factor of 2. The model also allows identifying the main parameters, which affect the long-term loss of strength of polymer-impregnated AR-glass. The diffusion coefficient of the polymer as well as the shape of the reinforcement both affects the long-term loss of strength dramatically. Low diffusion coefficients (such as typical for prepreg-epoxy systems) as well as compact reinforcement cross-sections minimize the strength loss.
Degree
thesis:*- Grantor dc:publisher
- Publikationsserver der RWTH Aachen University
- Year dc:date
- 2012
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Büttner, Till
- Contributors dc:contributor
-
- Raupach, Michael
Subjects
dc:subject × 11Rights
dc:rights- Statement dc:rights
-
- info:eu-repo/semantics/openAccess
- Language dc:language
- ger