1 2 4
CONTENTS
1 2 З? 4 5 6 7 8 9 10 EN 933-9:2009+ 1 Scope 1
2 Normative references 1
З? Terms and definitions 2
4 Principle 2
5 Reagents 3
6 Apparatus 3
7 Preparation of test portions 4
8 Procedure 4
9 Calculation and expression of results . 6
10 Test report 7
Annex A (normative)
Procedure for the determination of the methylene blue value (MB F ) of the 0/0,125 mm fraction 8
Annex Test of conformity in relation to a specified MB value 9
Annex C (normative)
Preparation of 10 g/l methylene blue solution 10
Annex D (normative)
Procedure for the determination of the methylene blue value of kaolinite (MB K ) 12
Annex E (informative) Example of a test data sheet 14
EN 933-9:2009 + - - - - а?) б?) в?) г?)
TESTS FOR GEOMETRICAL PROPERTIES OF AGGREGATESPart 9: Assessment of finesMethylene blue test
1 2 EN 932-2 EN 932-5 1 SCOPE
This standard describes the reference method used for type testing and in cases of dispute for the determination of the methylene blue value of the 0/2 mm fraction in fine aggregates or all-in aggregates (MB). It also describes the reference method for the determination of the methylene blue value of the 0/0,125 mm fraction (MBF) in Annex A. For other purposes, in particular factory production control, other methods may be used provided that an appropriate working relationship with the suitable reference method has been established.
2 NORMATIVE REFERENCES
The following referenced documents are indispensable for the application of this document. For undated references, the latest edition of the referenced document (including any amendments) applies
EN 932-2, Tests for general properties of aggregates - Part 2: Methods for reducing laboratory samples
EN 932-5, Tests for general properties of aggregates - Part 5: Common equipment and calibration
3.1 3.2 3.3 3.4 3.5 4 For the purposes of this document the following terms and definitions apply.
3.1 subsample
sample obtained by means of a sample reduction procedure
3.2 test portion
sample used as a whole in a single test
3.3 fines
particle size fraction of an aggregate which passes the 0,063 mm sieve
3.4 particle size fraction
fraction of an aggregate passing the larger of two sieves and retained on the smaller
NOTE The lower limit can be zero.
3.5 constant mass
successive weighings after drying at least 1 h apart not differing by more than 0,1 %
NOTE In many cases constant mass can be achieved after a test specimen has been dried for a pre-determined period in a specified oven at (110 4 PRINCIPLE
Increments of a solution of methylene blue are added successively to a suspension of the test portion in water. The adsorption of dye solution by the test portion is checked after each addition of solution by carrying out a stain test on filter paper to detect the presence of free dye.
When the presence of free dye is confirmed the methylene blue value (MB or MBF) is calculated and expressed as grams of dye adsorbed per kilogram of the size fraction tested.
NOTE A conformity check, adding a single quantity of dye solution equivalent to a specified limiting value and which may be used as part of a production control process, is described in Annex B.
5 5.1 5.2 5.3 6 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10 6.11 6.12 6.13 5 REAGENTS
5.1 Dye solution, solution of standard or technical quality methylene blue, (10,0 5.2 Distilled or demineralised water.
5.3 Kaolinite, of known methylene blue value (MBK) (see Annex D).
NOTE Kaoiinite of MBK value between 1 g and 2 g per 100 g of kaoiinite is preferable in order to avoid excessive use of dye.
6 APPARATUS
All apparatus shall conform to the general requirements of EN 932-5.
6.1 Burette, with capacity of either 100 ml or 50 ml and graduation of either 1/10 ml or 1/5 ml, or one 5 ml and one 2 ml micro-pipette.
6.2 Filter paper, quantitative and ash-free (< 0,010 %); 95 g/m 2 ; thickness 0,20 mm; filtration speed 75 s; pore size 8 p.m.
6.3 Glass rod, length 300 mm; diameter 8 mm.
6.4 Impeller agitator, capable of controlled variable rotation rates up to (600 NOTE Alternative types of mixer can be used if it can be shown that results obtained agree with results produced using an impeller agitator as specified above.
6.5 Balance, readable to 0,1 % of the mass to be weighed.
6.6 Stopwatch or stopclock, readable to 1 s.
6.7 Test sieve, 2 mm aperture, with guard sieve (if necessary).
6.8 Beaker, glass or plastic, capacity about 1 I or about 2 I.
6.9 Flask, glass, capacity 1 I.
6.10 Ventilated oven, thermostatically controlled to maintain a temperature of (110 6.11 Thermometer, readable to 1 6.12 Spatula.
6.13 Desiccator.
7 IV (%) = 100 8 3.1 8.2 8.3 8.2 Preparation of suspension
Place (500 Stir the dye solution (see 5.1) or alternatively mix it thoroughly. Fill the burette with dye solution and return the stock of dye solution to a dark place.
Set the agitator to a speed of 600 min -1 and position the impeller about 10 mm above the base of the beaker.
Switch on the agitator and start the stopwatch, agitating the contents of the beaker for 5 min at (600 If insufficient fines are present in the test portion to obtain a halo, kaolinite should be added together with additional dye solution as follows: Add to the beaker (30,0 Add V' ml of dye solution to the beaker where V' - 30 MB K , is the volume of dye solution adsorbed by 30 g of kaoiinite.
8.3 Determination of the quantity of dye adsorbed
Place the filter paper (6.2) on top of an empty beaker, or some other suitable support, so that most of its surface is not in contact with any solid or liquid.
After agitating for 5 min at (600 9
of dye and doing stain tests in this manner until a halo is observed. When this stage is reached, continue agitating and without further additions of dye solution, perform stain tests at 1 min intervals.
If the halo disappears during the first 4 min, add a further 5 ml of dye solution. If the halo disappears during the fifth minute, add only 2 ml of dye solution. In either case, continue agitating and doing stain tests until a halo persists for 5 min.
Record the total volume of dye solution V 1 added to produce a halo that persists for 5 min, to the nearest 1 ml.
NOTE Containers should be cleansed thoroughly with water as soon as the tests are completed. Traces of any detergents used should be removed by thorough rinsing. It is recommended that containers used in methylene blue tests are reserved specifically for that test.
9 CALCULATION AND EXPRESSION OF RESULTS
The methylene blue value, MB, expressed in grams of dye per kilogram of the 0/2 mm fraction is given by the following equation:
(2)
My - V 1 - V' - where
Vy is the total volume of dye solution injected, in millilitres.
Record the MB value to the nearest 0,1 g of dye per kilogram of the 0/2 mm fraction.
If the test is carried out with the addition of kaoiinite, the above equation becomes:
A/ - x1 My
where
V' is the volume of dye solution adsorbed by the kaolinite, in millilitres.
NOTE 1 The factor 10 in the above equations converts the volume of dye solution used to the mass of dye adsorbed per kilogram of the size fraction tested.
10 10.1 10.2 а?) Ь?) с?) d) е?) f) h) 10.3 а?) Ь?) с?) NOTE 2 An example of a test data sheet is given in Annex E.
10 TEST REPORT
10.1 General
The test report shall include the information referred to in 10.2 and can include the information referred to in 10.3.
10.2 Required data
a) reference to this European Standard;
b) identity of laboratory;
c) identification of the sample;
d) description of the material tested;
e) MB value;
f) date of receipt of sample;
g) sampling certificate, if available;
h) pre-drying (if any).
10.3 Optional data
a) name and location of the sample source;
b) description of the sample reduction procedure; c) date of test.
Vy - ANNEX PROCEDURE FOR THE DETERMINATIONOF THE METHYLENE BLUE VALUE (MB F ) OF THE 0/0,125 mm FRACTION
A.1 Prepare test portions as specified in Clause 7 and follow the test procedure in Clause 8, but with a test portion mass My of (30,0 A.2 Calculate the methylene blue value (MB F ) in grams of dye per kilogram of the 0/0,1 25 mm fraction as:
(A.1)
where
My is the mass of the test portion, in grams;
Vy is the total volume of dye solution added, in millilitres.
A.3 Record the MB F value to the nearest 0,1 g of dye per kilogram of the 0/0,125 mm fraction.
A.4 Test reports shall include appropriate information in accordance with Clause 10. TEST OF CONFORMITY IN RELATIONTO A SPECIFIED MB VALUE
A check on conformity with a specified MB value can be carried out by making a single addition of dye solution in the following manner.
If the specified MB value expressed as grams of dye per kilogram of 0/2 mm fraction is 'MB] then the volume of dye solution to be injected at one time, V 2 , is given by the following equation: MB] ■? M] 10
+ (B.1)
M] - MB] - V' - where
MB] is the specified MB value, in grams of dye per kilogram of 0/2 mm fraction;
V' is the volume of dye solution in millilitres adsorbed by any added kaoiinite.
After preparation of a test portion in accordance with Clause 7, the suspension should be prepared using the test portion, the water and, if necessary the kaoiinite, all in accordance with 8.2, but including V 2 ml of dye solution.
The stain test should be carried out after stirring the suspension for 8 min at (400 If this stain test is negative however, the complete determination described in 8.3 should be carried out.
M h - ANNEX PREPARATION OF 10 g/lMETHYLENE BLUE SOLUTION
C.1 Prepare the 10 g/l dye solution following the procedure given in C.1.1 to C.1.7.
C.1.1 Use methylene blue; (C 16 H 18 CIN 3 S, nH 2 0 (n = 2 to 3) purity > 98,5 %).
C.1.2 Determine the water content W of the methylene blue powder as follows:
Weigh approximately 5 g of methylene blue powder and record the mass to the nearest 0,01 g as M h .
Dry this powder at (100 NOTE At temperatures above 105 Calculate an