AS 1141.24:2018 pdf free

AS 1141.24:2018 pdf free.Methods for sampling and testing aggregates
This test method is designed to assess the resistance of the rock fabric to salt crystallization pressure, which is a measure of the susceptibility of the rock to physical breakdown. The extent of this breakdown is assessed by repeated immersion of the aggregate in a saturated solution of sodium sulfate followed by oven drying to dehydrate the salt precipitated in permeable pores and rehydration of the salt during subsequent immersion, which generates crystallization pressure. Internal expansive forces, derived from rehydration of the salt on re-immersion, mimic freezing (crystallization of water) or salt action. This provides a measure of the integrity of the rock fabric when subjected to physical weathering associated with the expansion on freezing of water in aggregate pores, and the expansion of salts on rehydration in marine conditions following repeated wetting and drying.
Bath (constant temperature)- of material that is resistant to the corrosive effects of solutions of sodium sulfate. Alternatively, a commercially available bath may be used,with an inserted bath of corrosion-resistant material, or of a material that is considered expendable. The bath shall operate in such a manner that the temperature of the sodium sulfate solution is maintained at 23±1°C at any point in the area of the bath containing the solution at a depth not less than 75 mm below the surface of the solution. The bath shall be cleaned out every three weeks during use if no liner is used.
NOTE: The success of this method is critically dependent on exposure of the aggregate to a saturated solution of sodium sulfate at all times. The solubility of sodium sulfate is temperature dependent around the specified operating temperature of the bath. In some locations in Australia, baths may require both heating and refrigeration controls to maintain operation within specification. Records of bath operating temperature over time should be maintained at least until constant temperature operation can be demonstrated. AS 1141.24 pdf free download.