Civil Engineering Reference
In-Depth Information
As the years passed, other Parts of the Standard were finalised by the CEN
internal enquiry and approval process and then issued, such that by 2006
ENV1504-9 needed to be revised by TC104/SC8 to bring it into alignment
with the latest thinking on the performance requirements for products
and systems for protection and repair. Over the period from 1990, several
significant advances had also been made in the technology of repair and
strengthening concrete structures, including the use of carbon fibre plates,
strips and wraps for structural strengthening of members, development of
topically applied corrosion inhibitors and the increasingly widespread use of
impressed current cathodic protection systems.
In parallel with development of the performance standards, TC104/
SC8 and its working groups also prepared standards for the supporting test
methods, which would be used to evaluate the performance of the products
and systems. The purpose was to select a single method of test for each
performance requirement. CEN has a strict procedure that its working
groups must follow when considering whether new draft standards need to
be developed, as set out below:
•
first, whether an existing ISO test method can be used;
•
second, whether an existing CEN member country's national standard
can be used;
•
third, whether another method can be developed from a recognised
body, such as RILEM, DAfSTb or BRE or from other research sources.
In a few cases, well-established ISO or national methods could be selected,
either used as they were, or slightly adapted; examples include the epoxide
equivalent of resin adhesives and the viscosity of paints.
In most cases, the existing test methods needed significant adaptation for
use with the formulations of repair products and systems on the market. For
example, EN 12190
Determination of compressive strength of repair mortar
is based on BS 6319
Testing of resin and polymer/cement compositions for
use in construction: Part 2 Compressive Strength
. Other test standards have
been re-written from national or learned guidance, such as the RILEM
Thermal Compatibility Tests I & II for paints applied to concrete, which
have been adapted for use on overlays of concrete repair mortar bonded
onto a reference substrate, creating EN 13687
Determination of thermal
compatibility
; EN 13687-1 is based on the RILEM freeze-thaw cycling
test with de-icing salt immersion and EN 13687-2 is the thunder shower
(thermal shock) test.
In other cases, TC104/SC8 agreed that no appropriate test method existed
for measuring the specialist properties of repair products or systems. New
methods of test were drafted based on the best available practice around the
world and the drafts circulated among CEN member countries until universal
agreement was achieved, often by pooling research knowledge; examples
include EN 13396,
Measurement of chloride ion ingress
(bulk diffusion
