DAfStb guideline - Strengthening of Concrete Structures with Adhesively Bonded Reinforcement - page 3

2 DAfStb guideline

2.1 The reasons for drawing up a guideline
In the past, the product systems as well as the design and installation of adhesively
bonded reinforcement were regulated in Germany by national technical approvals and
individual approvals. Such approvals contained provisions covering the materials, the
design of the strengthening measures, the work on site and the monitoring of products.
There were several reasons why it was deemed necessary to revise the design
approaches of the earlier approvals.
One of those reasons was the harmonization of standards across Europe, leading to
national standards and regulations being successively adapted to the European standards.
These developments also render it necessary to adapt the former national approvals to the
new generation of standards.
Furthermore, the results of numerous research projects carried out in recent years had
only been partly incorporated in the older regulations, which therefore no longer
matched the current state of knowledge. Therefore, industry, the building authorities
and the German Research Foundation (DFG) made substantial funds available for
researching adhesively bonded reinforcement. That led to many scientific projects in the
German-speaking countries and adhesively bonded reinforcement gradually becoming a
standard method in the building industry. Consequently, all the groups involved
regarded the preparation of a universal guideline as indispensable.

2.2 Preparatory work
In order to produce a universal guideline re ecting the current level of knowledge, the
German Committee for Structural Concrete (DAfStb) first commissioned a report
on the current situation [7] to document and collate national and international
knowledge. A database of test results containing almost all the experimental studies
carried out nationally and internationally was also set up and compared with the
established models and the guidelines available elsewhere in the world. During the
drafting of the report it became apparent that the knowledge necessary to produce an
effective guideline was lacking in some areas. Therefore, under the direction of the
DAfStb, a research project was initiated in which all the groups interested took part.
The research work was carried out by the technical universities in Munich and
Brunswick, both of which had been working continually on adhesively bonded
reinforcement for more than 20 years. The project was financed by the owners of
the approvals (Bilfinger Berger AG, Laumer Bautechnik GmbH, Ludwig Freytag
GmbH & Co. KG, MC-Bauchemie Müller GmbH & Co. KG, S&P Clever
Reinforcement Company AG, Sika Deutschland GmbH, Stocretec GmbH), the
Federal Institute for Research on Building, Urban Affairs & Spatial Development
(BBSR) plus a number of associations and consulting engineers. Issues surrounding
the bond strength under static loads [9] and dynamic loads [10] plus the shear
strength [11] were successfully clari ed during this project.