Description

This Standard sets out a separate solution method which can be used in aggregate or concrete laboratories to indicate whether chlorides or sulphates are present over a threshold detectable quantity.

Scope

This Standard sets out a method for the determination of chloride content and sulfate content (including easily oxidizable sulfide content) of concrete and concrete aggregates. The solutions obtained from the sample may also be used to determine the acidsoluble calcium oxide content of these materials. The method of solution will react with and dissolve any easily oxidizable sulfides which are present and these will be reported as sulfate. Such sulfides have been shown to be deleterious to concrete and the method provides an approach to limiting their inclusion in concrete and concrete aggregates. For compliance with the relevant requirements specified in AS 3600, additional tests and calculations may be required.

Notes: Separate test methods are available for the analysis of the other concretemaking materials, e.g. cementious materials, admixtures, water.

Gross variations in the chloride and sulfate contents of concrete and concretemaking materials can occur over distances of even a few millimetres. This can be caused, for example, by leaching with rainwater, surface evaporation and crusting and penetration of salt and ground waters. Sampling technique is of prime importance. As the effect of the use of water during coring, especially small diameter cores, can be significant, the amount of water used should be restricted.