Dimensioning and construction recommendation for statically effective mounting parts in textile reinforced prefabricated concrete elements
Table of contents
Project data
| Titel | Title
Bemessungs- und Konstruktionsempfehlungen für statisch wirksame Einbauteile in Textilbetonfertigteilen | Dimensioning and construction recommendation for statically effective mounting parts in textile reinforced prefabricated concrete elements |
Report in the yearbook 2015
Mounting parts for thin TRC elements
Pull-out test of a flat anchor with a concrete cover of 16 mm
The usage of textile reinforced concrete (TRC) in building practice shows, that besides the strengthening of existing structures, thin prefabricated elements of TRC can be an economical alternative to conventional building practice. An increasing number of applied and proposed building approvals, e.g. for façade elements, sandwich constructions and small garages, indicate the high potential of the composite material for new structures. Due to the facility of the material to adapt to various shapes, it is possible to build thin pre-cast, accurately sized and easily transportable elements in different shapes.
The connection of a textile reinforced concrete element to a building, as well as the handling of the element during stripping and delivery, requires diverse mounting parts, which in turn shall transfer the occurring forces in a safe and permanent manner. Using existing products that are designed for the purpose of connecting items impede the economical usage of TRC for prefabricated elements since they have to be adapted to each single project. For that reason, actual existing mounting parts have been analysed, selected and adapted to the newly developed design and construction recommendations, which are suitable for typical TRC elements and manufacturing technologies.
Besides the capacity to withstand mechanical and thermal stresses, manufacturing technologies have been studied within the project. A heavy-tow carbon textile and a workable concrete were chosen to meet typical requirements of TRC usage. Using these materials in the production of a test specimen, the cost effectiveness of this pre-cast concrete technology in connection with the accurate placement of the connection elements was studied in detail.
The load bearing behaviour was tested under different directions of stress, concrete strengths and concrete coverings for diverse mounting elements, which could be placed either on the face side or throughout the surface of prefabricated elements. As a result it was possible to develop design recommendations in connection with construction requirements.
Report in the yearbook 2014
Connecting elements
Textile reinforcement with threaded sleeve prepared for concreting
Due to the growing experience with textile reinforced concrete (TRC), the usage of the composite material in building practice is increasing. Up to now, especially pilot and demonstration projects have been completed. Among them are the strengthening of structural elements, construction of lightweight bridges, smaller buildings and diverse façade elements. It was proven that TRC is particularly suitable for reinforcing existing structures and for prefabricated elements. Thanks to the good formability of the textile reinforcement, elements are thin, accurately sized, easily transportable, and cast in different shapes.
These textile reinforced prefabricated concrete elements need statically effective mounting parts for casting and formwork removal, transport and for the connection to other structural elements. The mounting parts have to transfer forces permanently and safely in the TRC. In addition, an accurate placement of these parts must be ensured throughout the fabrication process. To date, purpose-built items or existing products for reinforced concrete or fibre cement have been used, which have been adapted and tested according to the requirements. This practice is costly in terms of time and money and prevents the usage of TRC for prefabricated elements. Therefore, design and construction recommendations suitable for typical TRC elements and manufacturing technologies need to be developed if we want to produce TRC elements economically and effectively.
For an economic and effective fabrication of TRC elements, design and construction recommendation must be developed which are suitable for typical TRC elements and manufacturing technologies. Therefore, actual existing mounting parts are analysed, selected and adapted to meet the requirements of thin TRC elements. In the future, suitable mounting parts can be identified and used based on the recommendations that will be developed from theoretical considerations and practical tests. Throughout the project, three main groups of mounting parts are analysed:
- anchors for transportation and permanent installations,
- shear load bearing elements for sandwich constructions,
- parts for frontal connections and framing.
In addition to the load bearing behaviour of the mounting parts, the manufacturing technologies are studied. The pouring of concrete into forms is the most economic casting technology, which implies taking into account specific prefabrication requirements.