Overview
A new type of connection was developed recently to carry out the steel-concrete connection of composite beams used in the field of the bridges. This innovative connection transmits the longitudinal shear by friction between the steel beam and the prefabricated concrete slab by means of a ribbed sheet and of a cement grout.
Theoretical and experimental studies showed the good resistance of this connection under static loads and that the technological aspects concerning its practical realisation had been solved. The advantages of this new connection are the speed of construction, thus decreasing the time of construction of a composite bridge and the durability of the connection and of the composite bridge thanks to a transmission of efforts by friction.
The behaviour under variable load of this connection by adherence, although promising, was not examined and analysed in a scientific and detailed way. A model of behaviour and a method of calculation for this case do not exist. It is needed to acquire an experimental data base in this field by means of fatigue tests carried out on push-out test specimen The test results will be used to justify the good resistance to fatigue of this connection and will make it possible to develop a dimensioning method.
The new steel-concrete connection resisting by adherence which can be used in the field of composite bridges showed its remarkable resistance under static loads. However, knowledge relating to this innovative connection must still be extended, in particular with regard to its behaviour under variable loads.
The aim of this research is to acquire this knowledge by means of fatigue tests carried out on push-out test specimen. The experimental results obtained will be used as references to justify the theoretical models describing the behaviour under variable loads, models whose developments are supported by another financial contribution.
In general, the project has these steps:
- To manufacture and instrument the test specimens,
- To carry out the stress tests, the duration is four to five weeks,
- To collect and format the test results
In order to obtain the desirable uniformity of the test specimens, it is necessary to make these test specimens simultaneously. Therefore, further steps are:
- Preparation and discussion to manufacturing and control specimens, making contacts with businesses (precast concrete, metal construction, injection)
- Production of the first specimens with embedded instrumentation in the test tubes,
- Instrumentation and Test 12 and push-out pieces of the beam,
- Formatting results.
Recall that the counting, analysis and exploitation of experimental results is not part of the funding for this research.
Funding
Results
Project is more experimental so key results are mostly laboratory test results.
Technical Implications
This experimental research on fatigue behavior of the new connection is required to use this type of connection in the field of road bridges. This knowledge will allow the development and justification of tools used by designers for dimensioning of these connections for the use of the rapid construction of composite bridges.
The audit approach to fatigue of this new connection, developed from the test results, will complement the design method recently developed and published [1].
[1] THOMANN, Michel. NEW CONNECTION FOR CONCRETE-STEEL GRIP.In: Documentation SIA No. D 0212. Swiss Society of Engineers and Architects, Zurich, 2005, p. 43-53.