EN 14629:2007 – Products and systems for the protection and repair of concrete structures – Test methods – Determination of chloride content in hardened concrete
1 Scope
This standard describes two methods for the determination of the total (free and bound) acid soluble chloride content of hardened concrete or mortar. This information is intended for use in estimating the risk of chlorideinduced corrosion of the steel reinforcement. It may be used on samples of powder obtained either by drilling or from cores or fragments removed from concrete structures or on other appropriate laboratory specimens.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 384, Laboratory glassware – Principles of design and construction of volumetric glassware
3 Materials and apparatus
3.1 Chemicals
Deionised water with an electrical conductivity less than 2µS/cm;
Nitric acid (5 mol/l);
Silver nitrate solution (0,02 mol/l);
Ammonium thiocyanate (NH 4 SCN) solution (0,1 mol/l);
Ammonium ferric sulfate indicator solution (100 ml of a cold saturated solution of NH 4 Fe(SO 4 ) 2 and 10 ml diluted nitric acid);
3,5,5-trimethylhexanol.
NOTE For the potentiometric method, additional reagents may be required as specified by the electrode
manufacturer to ensure the proper functioning of the electrode. These will be specified in the manufacturer’s instructions for the electrode.
3.2 Apparatus
Crushing and grinding equipment (as required to prepare samples);
1,18 mm sieve or smaller;
ventilated oven, controlled to maintain a temperature of (105 ± 5) °C;
balance capable of weighing up to 5 g to an accuracy of 1 mg;
desiccator;
burette, accurate to 0,05 ml;
250 ml glass beaker;
magnetic stirrer;
4 Test procedure
4.1 Sampling
4.1.1 Sampling plan
Sampling shall be in accordance with a plan prepared for the assessment or repair works by a suitably qualified person. When specifying the locations from which concrete is to be removed, specific care shall be taken of the load bearing capacity and reinforcement of the elements to be sampled. The plan shall take into account:
the size, form, location, orientation, age and structural design of the structure;
the results of visual surveys and any other available information about possible deterioration;
the aggregate size and the heterogeneous nature of the concrete;
exposure conditions, eg. salt water splash zones.
EN 14629:2007 – Products and systems for the protection and repair of concrete structures – Test methods – Determination of chloride content in hardened concrete