The background, history of the hydrodemolition development
“We can’t afford to use Jackhammers”
(Statement by Swedish National Road Administration)
A statement from the early ‘80s done by the Swedish National Road Administration (SNRA). They were facing major problems with the repair method by using jackhammers on bridge structures.
When the concrete on a bridge was damaged and in need of repair, the traditional method of repair was to use jackhammers. However, when core samples were taken, there were several cracks identified in the old part of the structure, the part that was supposed to remain. The consequences of these micro-cracks were that the bonding between old and new concrete was not good enough. Such repair started to delaminate within a rather short period. This was of major concern to SNRA as it affected the quality of the repair, the life length of the repair, as well as the overall life of the entire bridge. SNRA expressed, “We can’t afford to use jackhammers we need to find a new and better solution to remove deteriorated concrete on the bridges”. SNRA initiated a project, stated the criteria, and started to find some partners to participate.
The partners – Atlas Copco AB, a large manufacturer of construction and mining equipment, was contacted to develop and produce a machine that could meet the requested criteria; ABV (today NCC – Nordic Construction Company), a contractor that could operate the machine and verify that the machine fulfilled the criteria when operating on the bridge; Stockholm Street and Laboratories; and CBI (Cement och Betong Institutet – New name is RISE), were organizations involved to test and verify so the stipulated criteria were obtained from the scientific point of view.
A new non-destructive method was invented.
A new process, hydrodemolition, was developed to remove the bad concrete without causing damage to the remaining concrete. In other words, it is a non-destructive method invented for the removal of damaged concrete mainly used on sensitive concrete structures. A simple semi-automatic prototype robot was built and used to proceed with testing on a bridge. Djuröbron, outside Stockholm, Sweden.
Links
Access the full publication here:
Help us to improve
If you have a suggestion about this content, detect any typo or simply want to send us comments or proposals, you can use the following form to contact EWJI.
