Chloride in Aggregates and BS8500

When aggregates are dredged from marine locations they carry a significant amount of Chloride with them which is retained on the surfaces and pores of the aggregate material. This must be removed by washing prior to being sent for use in the construction industry. The limits of the Chloride contamination is well defined and can be measure simply using our dedicated instrument.

The SALCON II Salt Concentration Meter and British Standards

The EDT directION Salcon II Meter is designed to measure the water soluble Chloride ion content during Marine
Aggregate processing and prior to onward supply for concrete manufacturing.

Chlorides may be present in concrete from other constituent materials e.g. cement and admixtures. Field evidence shows that,
provided that the Chloride levels in the hardened concrete do not exceed the limits specified in BS8500, and that the normal
criteria for concrete quality and depth of cover are applied, there is no significant additional risk of reinforcement corrosion
from the use of marine dredged aggregate in concrete.

British and European Standards.

The guidance given for water soluble Chloride ion content can be summarised in the following European and British Standards
BS EN 12620 and BS EN 206-1.

The Standard BS EN 206-1 defines the chloride class depending on the type of reinforcing to be used. The class specifies the
maximum Chloride content in concrete by mass of cement from the total contribution of all the constituents.
The EDT SALCON II meter is designed to assist in the monitoring and management of the Chloride marine aggregate producers’
factory control procedures as required by BS EN 12620

The maximum chloride content in concrete ranges from 1.0% in un-reinforced structures to 0.1% in Pre-stressed steel
reinforcement.