AS 1012.20.2:2016 pdf free.Methods of testing concrete Method 20.2: Determination of water-soluble chloride in aggregates and hardened concrete.
5 REAGENTS AND STANDARD SOLUTIONS
Analytical quality reagents shall be used. The following are required:
(a) Distilled water Distilled water shall be used for the preparation of all reagents and standard solutions.
(b) Nitric acid Prepare a 1:4 diluted solution of concentrated nitric acid. Cautiously add 100 mL of nitric acid (15 mol/L or 1.42 g/mL) to 400 mL of water while stirring.
(c) Methyl orange indicator Dissolve 2 g of methyl orange per litre of 95% ethyl alcohol.
(d) Silver nitrate standard solution Prepare a solution of 0.05 mol/L silver nitrate and standardize against 5.00 mL of standard 0.05 mol/L sodium chloride solution, diluted with water to 150 mL.
(e) Sodium chloride solution Prepare exactly I L of a 0.05 mol/L sodium chloride solution. Dry sodium chloride at 105 ±5°C to constant mass. Measure out 2922.2 rng of dried reagent, and dissolve in water and dilute to exactly 1 L in a volumetric flask and mix thoroughly. This solution is the standard and requires no further standardization.
NOTE: Methods for the preparation of standard solutions are available in many reference chemical texts. Reference can also be made to CSA A23.2-4B.
6 APPARATUS
The following apparatus is required:
(a) Balance An analytical balance of adequate capacity and with a limit of performance of ±0.0005 g.
(b) Burette 10 mL capacity with 0.05 mL graduations.
(c) Fume cupboard.
NOTE: Advice on suitable fume cupboards can be found in AS/NZS 2243.8.
(d) Grinder Capable of grinding hardened concrete and aggregates to pass an 850 I.tm sieve.
(e) Ion selective electrode Either a silver, chloride/sulphide ion selective electrode or a silver billet electrode coated with silver chloride with a reference electrode.
(f) Oven Capable of operating in the temperature range 100°C to 110°C.
(g) Potentiometer With millivolt scale graduated to I mV.
(h) Sieves Punched plate and woven wire test sieves of aperture 6.7 mm, 1. 18 mm, and 850 jim complying with AS 1152.
(i) Stirrer Magnetic stirrer and coated stirring bars.
7 SAMPLING AND SAMPLE PREPARATION
7.1 General
Sampling requirements should be fully detailed by the specifying authority.
Sampling shall be as follows, appropriate to the source of the sample:
(a) For sampling of an aggregate, or a hardened concrete, mortar or grout, take a sample of at least 1 kg, to be reduced by crushing and grinding as detailed in Clause 7.2, Items (a) to (d).AS 1012.20.2 pdf download.