AS 1141.24:2018 pdf free.Methods for sampling and testing aggregates Method 24: Aggregate soundness- Evaluation by exposure to sodium sulfate solution.
7 APPARATUS
The following apparatus. conforming with the relevant provisions of AS 1141.2 is required:
(a) Bala,ice—wjth a capacity of not less than 5 kg and a limit of performance not exceeding ±0.5 g.
(b) Bath (constant teinperature)—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 he 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.
(c) Containers—for immersing the samples of aggregate in the solution. Containers shall be perforated in such a manner as to permit free access of the solution to the sample and drainage of the solution from the sample without loss of aggregate. For any aggregate fraction size, at no time shall the perforations in the container used for that fraction exceed the opening of the sieve used to determine the loss for that fraction (see Tables 3 and 4).
NOTE: See Preface for copyright information about this Clause.
(d) Hvdrometer(s)—20/L20 hydrometers conforming to the requirements of ISO 649—1 and capable of measuring solution density within the range of at least 1. 155 g/inL to 1.170 g/mL with an accuracy of ±0.001 g/mL.
(e) Evaporation oven—capable of operating between 105°C—i 10°C, and with an average evaporation rate of 25 g/h over a four hour period from each beaker in the oven, when tested in accordance with the following procedures. In all other respects, the oven shall conform to the requirements of AS 1141.2, as follows:
(i) Each shelf of the oven intended to be part of the working space of the oven shall be tested at the same time.
(ii) Each shelf shall be charged with five 1 L glass beakers, one in each corner of the shelf, and one placed in the centre of the shelf. All beakers shall contain 500 g of water, initially at a temperature of 23°C ±2°C.
(iii) At the commencement of the test, the oven shall be empty and operating between
105°C — 110°C.
(iv) The beakers shall be placed in the oven as quickly as possible and the oven door shall then remain closed for the four-hour duration of the evaporation test.
(v) The evaporation rate shall be determined by the weight loss of each beaker.
(vi) Any shelf of the oven shall only be assessed as conforming to the evaporation requirements if each beaker on the shelf records a minimum loss of 100g.
(f) Sieves—in square perforated plate or square woven wire in sizes 75 mm, 53 mm,
37.5 mm, 26.5 mm, 19.0 mm, 16.0 mm. 13.2 mm, 9.50 mm. 8.00 mm, 6.70 mm
4.75 mm, 3.35 mm, 2.36 mm, 1.70 mm, 1.18 mm, 850 pm, 600 pm, 425 pm, 300 pm,and 212 pim.AS 1141.24 pdf download.