ДСТУ Б EN 196-5:2015
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1 2 4
1 2 З? 4 4.1 4.2 4.3 4.4 5 6 7 8 8.1 8.2 9 9.1 9.2 9.3 10 10.1 10.2 10.3 11 1 Scope 1
2 Normative references 1
З? Principle 1
4 General requirements for testing ... 2
4.1 Number of tests 2
4.2 Repeatability and reproducibility. . 2
4.3 Expression of masses, volumes and factors 2
4.4 Determination of constant mass. . 2
5 Preparation of a test sample of cement 2
6 Reagents 3
7 Apparatus 4
8 Standardization of solutions 5
8.1 Standardization of the EDTA solution 5
8.2 Standardization of the 0,1 mol/l solution of hydrochloric acid 7
9 Procedure 7
9.1 Storage and filtration 7
9.2 Determination of the hydroxyl ion concentration . 8
9.3 Determination of the calcium oxide concentration 8
10 Results 9
10.1 Calculation and expression of results 9
10.2 Assessment of pozzolanicity. . . 9
10.3 Repeatability and reproducibility 10
11 Reporting of results 11
Bibliography 12
EN 196-5:2011 - - - - -
Part 5: Pozzolanicity test for pozzolanic cement
This European Standard specifies the method of measuring the pozzolanicity of pozzolanic cements conforming to [1] EN 197-1. This standard does not apply to Portland pozzolana cements or to pozzolanas.
This method constitutes the reference procedure.
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 196-7, Methods of testing cement - Part 7: Methods of taking and preparing samples of cement
EN ISO 385:2005, Laboratory glassware - Burettes (ISO 385:2005)
EN ISO 835:2007, Laboratory glassware - Graduated pipettes (ISO 835:2007)
The pozzolanicity is assessed by comparing the concentration of calcium ion, expressed as calcium oxide, present in the aqueous solution in contact with the hydrated cement, after a fixed period of time, with the quantity of calcium ion capable of saturating a solution of the same alkalinity. The cement is considered to satisfy the test, i.e. gives a positive result, if the concentration of calcium ion in the solution is lower than the saturation concentration.
4 4.1 4.2 4.3 4.4 5 NOTE Experiment has shown that a mixture of 20 g of cement and 100 ml of water at 40 4 GENERAL REQUIREMENTS FOR TESTING
4.1 Number of tests
Where the determination is one of a series subject to statistical control, determination by a single test shall be the minimum required.
Where the determination is not part of a series subject to statistical control, the number of tests shall be two (see also 10.1).
In the case of dispute, the number of tests shall be two.
4.2 Repeatability and reproducibility
Repeatability and reproducibility in this document are expressed as repeatability standard deviations) and reproducibility standard deviation(s).
4.3 Expression of masses, volumes and factors
Express masses in grams to the nearest 0,000 1 g and volumes from the burette in millilitres to the nearest 0,05 ml. Express the factors of solutions, given by the mean of three determinations, to three decimal places.
4.4 Determination of constant mass
Determine constant mass by drying for successive periods at the stated temperature, or making successive 15 min ignitions, followed each time by cooling and then weighing. Constant mass is reached when the difference between two successive weighings is less than 0,000 5 g.
Before starting the determinations, treat the laboratory sample, taken in accordance with EN 196-7, as follows to obtain a homogenous test sample.
Take approximately 100 g of the sample using a sample divideror by quartering. Sieve this portion 6 6.1 6.2 6.3 6.4 6.5 6.6 6.7 on Carry out all operations as quickly as possible to ensure that the sample is exposed to ambient air only for the minimum time.
Use only reagents of analytical quality. References to water mean distilled or deionised water having an electrical conductivity < 0,5 mS/m. The quantities of reagents listed are to indicate concentrations; actual quantities to be prepared shall be adjusted according to the amounts required.
Unless otherwise stated (%) means percent by mass.
6.1 Concentrated hydrochloric acid (HCI), (p = 1,18 g/cm 3 to 1,19 g/cm 3 ).
6.2 Hydrochloric acid, about 0,1 mol/l, prepared by measuring with a graduated cylinder (7.16) 8,5 ml of concentrated hydrochloric acid (6.1) to a litre volumetric flask (7.10) containing about 500 ml of water and make up to 1 000ml with water. Determine the factor of normality of the solution as indicated in 8.2.
6.3 Dilute hydrochloric acid (1+2), prepared by adding 250 ml of concentrated hydrochloric acid (6.1) to 500 ml water.
6.4 Methyl orange, (dimethylaminoazobenzene p-sodium sulfonate).
6.5 Methyl orange indicator, prepared by dissolving (0,020 6.6 Sodium hydroxide, (NaOH).
6.7 Sodium hydroxide solution, prepared by dissolving (100 6.8 6.9 6.10 6.11 6.12 6.13 6.14 6.15 6.16 6.17 7 7.1 6.8 Calcium carbonate, ( 6.9 Sodium chloride, (NaCI), dried to constant mass at (110 6.10 Murexide, (ammonium purpurate).
6.11 Murexide indicator, prepared by grinding (1,0 6.12 EDTA, (dihydrated disodium salt of ethylenediaminetetra-acetic acid).
6.13 EDTA solution, about 0,03 mol/l, prepared by dissolving (11,17 6.14 Sodium carbonate, (Na 2 CO 3 ), dried to constant mass at (250 6.15 Mixed calcein and methylthymol blue indicator, prepared by grinding (0,20 6.16 Calcon indicator, prepared by grinding (1,0 6.17 Patton and Reeders reagent, prepared by mixing (1,0 7 APPARATUS
7.1 500 ml cylindrical polyethylene container, of about 70 mm diameter with a pressure sealplug locked by a screw plug, capable of preventing evaporation during storage.
7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 7.10 7.11 7.12 7.13 7.14 7.15 pH - 7.16 . 8 8.1 7.2 Wide stem funnel.
7.3 Porcelain Buchner funnel, of 60 mm inner diameter.
7.4 Filter paper, with low porosity (mean pore diameter of about 2 7.5 250 ml vacuum flask.
7.6 250 ml and 400 ml beakers.
7.7 50 ml and 100 ml pipettes, class A of EN ISO 835:2007.
7.8 50 ml burette, class A of EN ISO 385:2005.
7.9 Uniform temperature enclosure, controlled thermostatically at (40 7.10 500 ml and 1 000 ml volumetric flasks.
7.11 250 ml conical flask.
7.12 Balance, capable of weighing to an accuracy of 7.13 Apparatus for measuring the absorbance, at 520 nm and 620 nm of a solution contained in a titration beaker, while stirring.
7.14 Stirrer, e.g. magnetic stirrer, with inert, e.g. PTFE, covered bar.
7.15 pH meter, capable of measuring to an accuracy of 7.16 Graduated cylinder of 10 ml or 20 ml.
8.1 Standardization of the EDTA solution
Weigh to an accuracy of а?)
/77 1 - - 100,09 - Ь?) Determine the endpoint using one of the following two methods.
a) Photometric determination of the endpoint (reference method):
Add, without weighing, approximately 0,1 g of murexide indicator (6.11) or of mixed indicator (6.15). Place the beaker in the apparatus (7.13) set at 620 nm when using murexide or at 520 nm when using the mixed indicator and, while stirring continuously, titrate with 0,03 mol/l EDTA solution (6.13). In the vicinity of the colour change, construct a curve giving the absorbance values as a function of the volume of EDTA added. The volume V-j used is determined from the intersection of the line of greatest slope near the colour change and the line of almost constant absorbance after the colour change.
Calculate the factor, fj, of the EDTA solution from the formula:
(1)
where
m 1 is the mass of calcium carbonate, in grams;
V' 1 is the volume of EDTA solution used for the titration, in millilitres;
100,09 is the molecular mass of calcium carbonate, b) Visual determination of the end-point (alternative method)
Add, without weighing, about 0,1 g of the calcon indicator (6.16), or Patton and Reeders reagent mixture (6.17). Stir and titrate with the 0,03 mol/l EDTA solution (6.13) until the colour changes from pink to blue (purple to clear blue for Patton and Reeders reagent), and one drop in excess does not further increase the intensity of the blue 8.2 0,1
V 2 - 105,989 - 9 9.1 8.2 Standardization of the 0,1 mol/l solution of hydrochloric acid
Weigh, to an accuracy of Calculate the factor, f 2 , of the hydrochloric acid solution from the formula:
(2)
where
m 2 is the mass of sodium carbonate, in grams;
V 2 is the volume of hydrochloric acid used for the titration, in millilitres;
105,989 is the molecular mass of sodium carbonate.
9.1 Storage and filtration
Pipette 100 ml of freshly boiled water into the polyethylene container (7.1), seal and place in the uniform temperature enclosure (7.9) until equilibrium is reached (about 1 h). Remove the container from the uniform temperature enclosure. Pour (20,00 Shake vigorously for about 20 s to avoid formation of cement lumps. Use a horizontal rotary motion to prevent any part of the sample or liquid being thrown up and remaining separated from the rest of the solution.
Replace the container in the uniform temperature enclosure, making sure that its base is horizontal 9.2 [ f 2 - 9.3 After a period of 8 d or 15 d in the uniform temperature enclosure, remove the container and filter the solution immediately under vacuum through the B?chner funnel (7.3) into the vacuum flask (7.5) using dry double filter paper (7.4) in less than 30 s (to avoid absorption of atmospheric carbon dioxide and any appreciable lowering in temperature of the solution). Seal the vacuum flask immediately and let the filtrate cool to room temperature.
NOTE If the cement satisfies the test at 8 d (see 10.2) it is not necessary to continue to 15 d.
9.2 Determination of the hydroxyl ion concentration
Shake the vacuum flask (7.5) to homogenise