Civil Engineering Reference
In-Depth Information
The principles of this are implicit in the overall approach of the BS EN
1504 Part 9 Eurocode on Concrete Repair (BSI, 2008). The overall approach
evolved from work started in the 1980s by CIRIA (Davies, 2010, Pullar-
Strecker 1987). However, the other parts of the standard have become
tangled with a plethora of tests and CE (conforming to EU consumer safety,
health or environmental requirements) ratings which do not facilitate the
selection of effective structural repairs matched to a particular structure.
Many of the properties of CE materials are geared for ease of application
and fast strength gain to aid the contractor on site, but these tend to be
detrimental to the long-term performance of the repair.
Matching repair properties with the structure concrete should be the
primary requirement in any repair specification. Many proprietary CE
repair products comply with EN 1504 but will be a poor match for most
concretes. The EN needs to be used to assess the properties so that a match
can be achieved.
Firstly, Young's modulus and the coefficient of thermal expansion need to
match. A starting point for this is the use of cement and aggregates similar to
the original. This will also help match the finished appearance.
