All tests shall be performed on materials of a grain size ≤ 0,2 mm Grain size distribution by sieving 6.1 and 6.2 Quicklime Material in the as-delivered state Grain size distribution b
General
Sampling must adhere to the guidelines outlined in sections 3.2 to 3.4, emphasizing the importance of minimizing moisture and carbon dioxide absorption To achieve this, samples should be transported and stored in airtight containers, and all handling processes should be executed promptly.
Sampling of powdered material
Sampling shall be carried out in accordance with EN 196-7.
Sampling of granular material
Sampling shall be carried out in accordance with EN 932-1.
Sampling of lime putty and milk of lime
The spot sample size shall be (10 ± 5) dm 3
Where lime putty or milk of lime is sampled, the increments shall be blended thoroughly.
Preparation of the test portion
Prior to analysis, the sample must be reduced in mass using a sample divider or quartering to create a homogeneous test sample of appropriate mass for the intended determinations Additionally, lime putty and milk of lime should be dried before conducting the chemical analysis.
The sample preparation for the appropriate test is described in Table 1
Table 1 ― Sample preparation for the single tests
Test Clause in this standard
Type and form of the building lime Sample preparation
Chemical analysis of building lime involves testing various types, including quicklime, hydrated lime, hydrated dolomitic lime, and lime with hydraulic properties The granular material sample must be crushed and ground to a grain size of 0.2 mm or less Grain size distribution is determined through sieving methods, including air-jet sieving, to ensure accurate assessment of the material's properties.
Material in the as-delivered state
Bulk density 6.3 All types of building lime See 6.3.2
Hydrated lime, lime with hydraulic properties
Material in the as-delivered state
6.4.2.3 Hydraulic lime with an SO 3 content of more than 3 % and up to 7 %
Material in the as-delivered state
6.4.3 Hydrated lime, lime putty und hydrated dolomitic lime Material in the as-delivered state 6.4.4 Quicklime, lime putty, dolomitic quicklime, hydrated dolomitic lime
Setting times 6.5 Lime with hydraulic properties Material in the as-delivered state
Reactivity 6.6 Quicklime The test shall be performed on materials of a grain size ≤ 0,2 mm
If 100 % of the material pass the
5 mm sieve the product can alternatively be tested in the as- delivered state
Mortar tests 6.8 to 6.10 Hydrated lime, hydrated dolomitic lime, lime with hydraulic properties
Material in the as-delivered state
Compressive strength 6.11 Lime with hydraulic properties Material in the as-delivered state
Number of tests
Analyzing building lime involves assessing various chemical properties, necessitating multiple tests for each property The number of measurements required for these tests is outlined in the relevant clauses of the standard.
Where the analysis is one of a series subject to statistical control, determination of each chemical property by a single test shall be the minimum required
Where the analysis is not part of a series subject to statistical control, the number of tests for determination of each chemical property shall be 2 (see also 4.3)
In the case of a dispute, the number of tests for determination of each chemical property shall be 2 (see also 4.3).
Repeatability and reproducibility
Repeatability refers to the precision achieved when independent test results are obtained using the same method on identical test items within the same laboratory, conducted by the same operator and utilizing the same equipment over short time intervals.
Reproducibility — Precision under reproducibility conditions where test results are obtained with the same method on identical test items (material) in different laboratories with different operators using different equipment
Repeatability and reproducibility in this document (see Annex B) are expressed as repeatability standard deviation(s) and reproducibility standard deviation(s) in e.g absolute percent, grams, etc., according to the property tested.
Expression of masses, volumes, factors and results
Express masses in grams to the nearest 0,001 g and volumes from burettes in millilitres to the nearest 0,05 ml
Express the factors of solutions, given by the mean of three measurements, to three decimal places
Express the results, where a single test result has been obtained, as a percentage generally to two decimal places
Express the results, where two test results have been obtained, as the mean of the results, as a percentage generally to two decimal places
If the two test results differ by more than twice the standard deviation of repeatability, repeat the test and take the mean of the two closest test results
The results of all individual tests shall be recorded.
Blank determinations
Carry out a blank determination without a sample, where relevant, following the same procedure and using the same amounts of reagents Correct the results obtained for the analytical determination accordingly.
Reagents
Use only reagents of analytical quality References to water mean distilled or deionised water having an electrical conductivity ≤ 0,5 mS/m
Unless otherwise stated percent means percent by mass
The densities (ρ) of concentrated liquids used for reagent preparation in this standard are specified in grams per milliliter at 20 °C Dilution is expressed as a volumetric ratio; for instance, a dilution of hydrochloric acid 1 + 2 indicates that one volume of concentrated hydrochloric acid should be combined with two volumes of water.
The concentrations of reference and standard volumetric solutions are specified as amount-of-substance concentrations, c (mol/l).
Evaluation of test results
The chemical requirements for building limes are specified in EN 459-1:2010, Tables 2, 9, 16, 20 and 24
For quicklime the specified values correspond to the finished product
4.6.3 Test results for all other types
For hydrated lime, lime putty, milk of lime, and lime with hydraulic properties, the values are calculated after removing free and bound water content The procedures outlined in the European Standard for determining total calcium oxide, magnesium oxide, sulfate, and carbon dioxide do not account for this water content To align these values with EN 459-1:2010, Tables 2 or 9, they must be adjusted by multiplying by a correction factor, F, which should be determined accordingly.
To determine the carbon dioxide content, refer to sections 5.5 or 5.6, and assess the loss on ignition as outlined in section 5.7 The loss on ignition encompasses the total of free water, bound water, and carbon dioxide, assuming the sample is free from highly volatile compounds or oxidizable constituents Calculate the total water content (free + bound) as a mass fraction percentage of the sample using the appropriate formula.
W T = loss on ignition in % − carbon dioxide content in percent (1) Calculate the factor F from the following equation:
4.6.4 Test results for available lime
The values for available lime, as determined by the method outlined in section 5.8, represent either the available CaO for quicklime or the available Ca(OH)₂ for other forms such as hydrated lime, lime putty, milk of lime, and lime with hydraulic properties.
Extraction with hydrochloric acid
Extraction with hydrochloric acid is used to dissolve building lime in order to determine calcium oxide and magnesium oxide
The sample undergoes boiling with hydrochloric acid, followed by filtration of the solution The pH is then adjusted to between 6 and 7 to precipitate iron (III) and aluminum oxides After a second filtration, the resulting filtrate is transferred to an appropriate volumetric flask.
5.1.3.1 Hydrochloric acid, ρ (HCI) = 1,16 to 1,19 g/ml
5.1.3.4 Ammonium hydroxide solution, c (NH 4 OH) = 25 %
5.1.4.4 Magnetic stirrer and magnetic rod, inert e.g PTFE covered
5.1.4.5 pH-meter with glass electrode, capable of measuring to an accuracy of 0,05
Weigh approximately 1 g of the sample with an accuracy of 0.001 g and transfer it to a 250 ml beaker Moisten the sample with 10 ml of water, then gradually add 30 ml of hydrochloric acid Dilute the solution to about 100 ml with water and boil for 10 minutes After boiling, filter the solution through fluted filter paper with a particle retention size of 2.5 µm into a 400 ml beaker, ensuring to wash the residue thoroughly with hot water.
To prepare the solution, add approximately 4 g of ammonium chloride and a few drops of hydrogen peroxide, then dilute with about 150 ml of water and heat to boiling While boiling, introduce ammonium hydroxide solution to adjust the pH to between 6 and 7, which will precipitate aluminum hydroxides, iron hydroxides, and soluble silicic acid.
Boil the mixture for 3 minutes, then filter the solution through fluted filter paper (particle retention size 2.5 µm) into a 500 ml volumetric flask after the precipitate has settled Rinse the filter residue three times with ammonium hydroxide solution and three times with water Once the solution has cooled to room temperature, fill the flask to the mark with water and shake thoroughly This prepared solution (V1) is now ready for further chemical analyses.
Calcium oxide (CaO) and magnesium oxide (MgO)
The method is suitable for determining calcium oxide and magnesium oxide
Calcium oxide is quantified in a test solution using complexation titration with EDTA at a pH of 13, where a calcium-specific indicator signals the endpoint through a color change Initially, EDTA reacts with free calcium ions, followed by those bound to the indicator, resulting in a distinct transition from wine red to blue.
In the same way, the total calcium oxide and magnesium oxide (Σ CaO + MgO) is determined at a pH value of
The titration process using EDTA and Eriochrome Black T as an indicator effectively measures the concentrations of calcium and magnesium ions Initially, EDTA reacts with free calcium and magnesium ions, followed by those attached to the indicator, resulting in a color change from red to blue The difference in the concentrations of calcium and magnesium allows for the determination of magnesium content.
5.2.3.1 Hydrochloric acid, ρ (HCI) = 1,16 g/ml to 1,19 g/ml
5.2.3.5 Sodium hydroxide solution, c (NaOH) = 4 mol/l
5.2.3.6 Ammonium hydroxide solution, c (NH 4 OH) = 25 %
5.2.3.8 Ethylenediaminetetra-acetic acid disodium salt dihydrate (EDTA), (C 10 H 14 N 2 Na 2 O 8 ⋅ 2 H 2 O), dried to constant mass at 80 °C before weighing
5.2.3.9 Calcium carbonate, c (CaCO 3 ) = 99,9 % (dried at (200 ± 10) °C)
Make 70 g of ammonium chloride (5.2.3.7) and 570 ml of ammonium hydroxide solution (5.2.3.6) up to the mark with water in a 1 000 ml volumetric flask
5.2.3.11 EDTA solution, c (EDTA) = 0,04 mol/l a) Preparation:
Dissolve 14,89 g of EDTA (5.2.3.8) in water and making up to 1 000 ml in a volumetric flask b) Standardization:
To prepare the calcium ion reference solution, pipette 50 ml into a 400 ml beaker and dilute with 100 ml of water Adjust the pH to (12.5 ± 0.5) using sodium hydroxide solution, monitored with a pH meter Then, add 0.1 g of calconcarboxylic indicator and titrate with the standardized EDTA solution until a blue color change occurs.
The concentration of the EDTA solution is given by the following equation:
= × (3) where m 2 is the initial mass of calcium carbonate taken to prepare the calcium ion reference solution, in grams;
V 2 is the volume of the EDTA solution used in the titration, in millilitres
5.2.3.12 Calcium ion reference solution, c (Ca 2+ ) = 0,01 mol/l
To prepare a calcium carbonate solution, transfer (1 ± 0.002) g of calcium carbonate to a 400 ml beaker along with approximately 100 ml of water Cover the beaker with a watch glass and carefully add about 10 ml of hydrochloric acid Once the calcium carbonate has fully dissolved, remove the carbon dioxide by boiling the solution, then allow it to cool before diluting it to a final volume of 1,000 ml in a volumetric flask.
Grind 0,2 g of calconcarboxylic acid intensively with 20 g of anhydrous sodium sulfate in a mortar
Grind 1 g of Eriochrome Black T intensively with 100 g of sodium chloride in a mortar
5.2.4.2 Magnetic stirrer with magnetic rod
5.2.4.3 pH-meter with glass electrode, capable of measuring to an accuracy of 0,05
To assess the calcium oxide content, take 25 ml (V 3 ) of the solution prepared as per section 5.1.5, transfer it to a 400 ml beaker, dilute with approximately 150 ml of water, and incorporate 5 ml of triethanolamine solution.
Adjust the pH value of this solution to (12,5 ± 0,5) with sodium hydroxide solution (5.2.3.5) using a pH-meter
To perform the titration, add 0.1 g of calconcarboxylic acid indicator and continuously stir the mixture with a magnetic stirrer while titrating with the EDTA solution Observe the color change from wine red to blue and record the volume (V₄) of the EDTA solution used.
EDTA solution added During titration the pH-value shall not fall below 12,0
5.2.5.2 Determination of total CaO and MgO content
In a 400 ml beaker, combine 150 ml of water with 25 ml of the prepared solution Introduce 5 ml of triethanolamine solution and adjust the pH to (10.5 ± 0.5) using a buffer solution, monitored with a pH meter Next, add approximately 90% of the EDTA solution volume used in the calcium oxide titration, followed by 0.1 g of Eriochrome Black T indicator Titrate the mixture until the color shifts from wine red to blue, and record the total volume used.
5.2.6 Evaluation and expression of results
The calcium oxide content of the sample expressed as CaO in mass fraction in percent is given by the following equation:
V 1 is the volume of the digestion solution (5.1.5), in millilitres;
V 3 is the volume of the aliquot of the digestion solution V 1 taken for titration as described in 5.2.5.1, in millilitres;
The volume of the EDTA solution used for determining CaO, denoted as V 4, is measured in millilitres The concentration of the EDTA solution, represented by c, is established as outlined in section 5.2.3.11 Additionally, m 1 refers to the mass of the test portion utilized, measured in grams, as specified in section 5.1.5.
The magnesium oxide content of the sample expressed as MgO in mass fraction in percent is given by the following equation:
V 1 is the volume of the digestion solution (5.1.5), in millilitres;
V 5 is the volume of the aliquot of the digestion solution V 1 taken for titration as described in 5.2.5.2, in millilitres;
V 4 is the volume of EDTA solution used for the CaO determination as described in 5.2.5.1, in millilitres;
V 6 is the volume of EDTA solution used for the determination of the total CaO and MgO as described in
5.2.5.2, in millilitres; c is the concentration of the EDTA solution, as determined in 5.2.3.11; m 1 is the mass, in grams, of the test portion used in 5.1.5.
Sulfate (expressed as SO 3 )
The method is used to determine the sulfate content of building lime
The sulfate compounds in the sample are dissolved in hydrochloric acid and the pH value is adjusted to 1 to
To prevent the precipitation of iron and aluminum oxides, the sulfate content is determined gravimetrically This involves boiling the solution and precipitating the sparingly soluble barium sulfate using a barium chloride solution.
5.3.3.1 Hydrochloric acid, ρ (HCI) = 1,16 g/ml to 1,19 g/ml
5.3.3.4 Nitric acid, ρ (HNO3) = 1,40 g/ml to 1,42 g/ml
5.3.3.5 Ammonium hydroxide solution, c (NH 4 OH) = 25 %
Dissolve 120 g of barium chloride in water and make up to 1 000 ml with water in a volumetric flask
Dissolve 5 g of silver nitrate (5.3.3.9) in water, add 10 ml of nitric acid (5.3.3.4) and making up to 1 000 ml with water in a volumetric flask
5.3.4.3 Hot plate or sand bath
Weigh out (1 ± 0.1) g of the sample (m₃) into a 250 ml beaker, add 90 ml of cold water, and then incorporate 10 ml of hydrochloric acid while stirring vigorously Heat the solution in a fume cupboard on a hot plate or sand bath to just below boiling point and maintain this temperature for 15 minutes Finally, filter the solution through fine filter paper with a mean pore diameter of approximately 2 µm and an ash content of less than 0.01%.
400 ml beaker and wash the residue several times with small portions of hot diluted hydrochloric acid (5.3.3.3)
Dilute the filtrate to approximately 250 ml with water and adjust the pH to 1 using hydrochloric acid or ammonium hydroxide solution if necessary Boil the solution for 5 minutes, then gradually add 10 ml of hot barium chloride solution while stirring continuously Continue boiling for an additional 15 minutes to ensure proper precipitate formation Finally, leave the precipitation vessel on a hot plate at 60 °C overnight, taking care to prevent evaporation.
Filter the precipitate through a fine filter paper (mean pore diameter of approximately 2 àm, ash content
To ensure the absence of chloride, wash the residue with boiling water and test the filtrate using silver nitrate solution After rinsing the funnel stem with water, collect the wash water in a test tube and add silver nitrate A lack of cloudiness indicates that chloride is absent; if cloudiness appears, continue washing until the silver nitrate test yields a negative result.
Transfer the filter paper and residue to a preweighed platinum crucible and incinerate to constant mass at
(925 ± 25) °C in a muffle furnace An incineration time of 15 min will generally be sufficient to achieve constant mass Record the mass (m 4)
5.3.6 Evaluation and expression of results
The sulfate content expressed as SO 3 in mass fraction in percent is given by the following equation:
SO 0 m m m m × × = × (6) where m 4 is the final mass of BaSO 4 , in grams; m 3 is the mass of the test portion, in grams.
Free water
The method is employed to assess the free water content in building lime For hydrated lime or lime with hydraulic properties, free water refers to the moisture bound to the product In the context of milk of lime or lime putty, it pertains to the water content present in the suspension.
Heating hydrated lime or lime with hydraulic properties to temperatures around (105 ± 5) °C, or milk of lime and lime putty to (150 ± 5) °C, results in the evaporation of free water This mass loss is identified as free water for hydrated lime and lime with hydraulic properties, while for milk of lime or lime putty, it is considered the water content in the suspension.
5.4.3.2 Drying oven, thermostatically controlled to maintain a temperature of (105 ± 5) °C or (150 ± 5) °C
5.4.3.3 Automated moisture balance, being capable to be controlled between (105 ± 5) °C or
5.4.4.1 Hydrated lime and lime with hydraulic properties
Weigh a sample in its as-delivered state, ranging between (5 ± 0.1) g and (10 ± 0.1) g, to the nearest 0.001 g in a pre-weighed crucible Dry the sample in an oven or balance until a constant mass is achieved.
To ensure effective drying, limit oven time to about 2 hours After removing the crucible from the oven, cover it to prevent the absorption of carbon dioxide and water vapor from the air Finally, cool the crucible in a desiccator and reweigh it.
5.4.4.2 Milk of lime and lime putty
Homogenize the suspension by shaking before taking the sample aliquot Use a pipette to take approximately
Weigh 20 g of the sample in a glass vessel, ensuring precision to the nearest 0.001 g Dry the sample to a constant mass using either an oven or a balance After removing the crucible from the oven, cover it to prevent the absorption of carbon dioxide and water vapor from the air Once cooled to room temperature in a desiccator, measure the loss in mass.
5.4.5 Evaluation and expression of results
The free water content expressed as H 2 O in mass fraction in percent is given by the following equation:
2 = 5− × m m m (7) where m 5 is the mass of the test portion before heating, in grams; m 6 is the mass of the test portion after heating, in grams.
Gravimetric determination of carbon dioxide (CO 2 ) (reference method)
The sample undergoes treatment with phosphoric acid to decompose the carbonate, releasing carbon dioxide This gas is then carried through a series of absorption tubes using carbon dioxide-free air The initial tubes eliminate hydrogen sulfide and water, while subsequent tubes absorb the carbon dioxide Two absorption tubes, filled with a granular absorbent for carbon dioxide and anhydrous magnesium perchlorate to capture the water produced, are weighed to measure the mass of the released carbon dioxide.
5.5.2.2 Phosphoric acid, ρ (H 3PO 4 ) = 1,71 g/ml to 1,75 g/ml
5.5.2.4 Saturated water solution of copper (II) sulphate
To prepare the mixture, weigh a quantity of dried pumice stone with a grain size of 1.2 mm to 2.4 mm and place it in a flat dish Cover the pumice with a saturated copper sulfate solution, ensuring the mass of the solution is about half that of the pumice stone Evaporate the mixture to dryness while stirring frequently with a glass rod, and then dry the contents in an oven at a temperature of at least 5 hours.
(150 ± 5) °C Allow the solid mixture to cool in a desiccator and store in an airtight bottle
Anhydrous magnesium perchlorate (Mg(ClO 4 ) 2 ) with a particle size between 0,6 mm and 1,2 mm
Synthetic silicates with a particle size between 0,6 mm to 1,2 mm impregnated with sodium hydroxide (NaOH)
NOTE This absorbent can be obtained ready for use
5.5.3.2 Apparatus for the determination of the carbon dioxide (reference method)
The apparatus depicted in Figure 1 can be equipped with a cylindrical pressure container, a small electrical compressor, or a suitable suction pump to maintain a consistent flow of gas or air Prior to entering the apparatus, the gas, whether air or nitrogen, undergoes a carbon dioxide removal process by passing through an absorbent tube or tower containing a carbon dioxide absorbent.
The 100 ml distillation flask is equipped with a three neck adaptor, where neck (5) connects to a dropping funnel, neck (6) links to a connecting tube, and neck (8) attaches to a water-cooled condenser A Y-piece facilitates the connection between the funnel and the connecting tube, allowing carbon dioxide-free air to flow through either pathway, controlled by a Mohr clip.
After passing through the condenser, the gas is treated with concentrated sulfuric acid before entering absorption tubes designed to capture hydrogen sulfide and water The process involves two absorption tubes filled primarily with an absorbent for carbon dioxide, with a smaller portion dedicated to water absorbent The carbon dioxide absorbent is positioned upstream of the water absorbent in relation to the gas flow Additionally, a subsequent absorption tube is included to safeguard the primary absorption tubes from carbon dioxide and water intrusion from the surrounding air.
3 absorption tower containing carbon dioxide absorbent (5.5.2.7)
10 wash bottle with concentrated sulfuric acid (5.5.2.1)
11 absorption tube with absorbent for hydrogen sulfide (5.5.2.5)
12 absorption tube with absorbent for water (5.5.2.6)
13 absorption tubes with absorbents for carbon dioxide (5.5.2.7) and water (5.5.2.6)
15 absorption tube with absorbents for carbon dioxide (5.5.2.7) and water (5.5.2.6)
Figure 1 — Typical apparatus for the determination of carbon dioxide (reference method)
The absorption tubes to be weighed have approximate dimensions of 45 mm for the external distance between branches, an internal diameter of 20 mm, a height of 75 mm from the lower part of the tube to the upper part of the ground section, and a wall thickness of 1.5 mm.
The mass of the building lime sample is determined by the expected CO₂ content, with specific amounts recommended for different ranges: 2 g for CO₂ levels between 0% and 2%, 1 g for levels exceeding 2% up to 5%, 0.5 g for levels above 5% to 10%, 0.3 g for levels from 10% to 15%, 0.2 g for levels between 15% and 40%, and 0.1 g for CO₂ concentrations exceeding 40% up to 50%.
Weigh 0.001 g of the sample and place it in a dry 100 ml distillation flask Connect the flask to the apparatus as illustrated in Figure 1, omitting the two absorption tubes For 15 minutes, pass a current of carbon dioxide-free gas through the apparatus at a rate of approximately three bubbles per second using the bubble counter After this, release the Mohr clip and disconnect the gas supply from the funnel Finally, add 30 ml of concentrated phosphoric acid into the dropping funnel and reconnect the gas supply to fill the funnel.
Condition the closed absorption tubes for 15 minutes in the balance case to ensure temperature equilibrium Next, weigh each tube individually After that, turn off the gas flow and connect the tubes to the apparatus as illustrated in Figure 1.
When handling tubes, it is crucial to take precautions to prevent weight alteration, damage, or personal injury Wearing protective gloves during this process is highly recommended for safety.
To reopen the gas flow, close the absorption tubes (13) after 10 minutes, remove them, and place them in the balance case for 15 minutes before weighing them individually Continue this process of gas passage, removal, and weighing of the absorption tubes (13) until the results of two consecutive weighings of a tube differ by no more than 0.0005 g.
If the change in mass of the absorption tubes (13) remains greater than 0,000 5 g, renew the absorbents in tubes (11) and (12)
Attach the weighed absorption tubes to the apparatus as illustrated in Figure 1 Open the funnel tap to let phosphoric acid flow into the distillation flask Once the reaction is complete, gently heat the flask's contents to boiling for 5 minutes Ensure the gas flow continues until the flask cools to room temperature.
Remove the closed absorption tubes (13) and place them in the balance case for 15 minutes before weighing them individually The mass increase of each tube is utilized to calculate the carbon dioxide content.
The carbon dioxide is practically completely absorbed by first tube (13) If the increase in mass of second tube
(13) exceeds 0,000 5 g, renew the absorbent in first tube (13) and start the test again
5.5.5 Evaluation and expression of results
Calculate the carbon dioxide content as CO 2 in mass fraction in percent from the following equation:
The equation \(2 = 8 + m_7 + m_8\) describes the relationship between the mass of a test portion and the mass increases observed in two tubes after absorption Here, \(m_7\) represents the mass of the test portion in grams, while \(m_8\) and \(m_9\) denote the mass increases of the first and second tubes, respectively, also measured in grams.
Volumetric determination of carbon dioxide (CO 2 ) (alternative method)
The CO 2 contained in the building lime in the form of carbonates is given off by reaction with hydrochloric acid and determined volumetrically
5.6.2.1 Hydrochloric acid, ρ (HCI) = 1,16 g/ml to 1,19 g/ml
Dissolve 0,2 g of methyl red (5.6.2.5) in water and make up to 100 ml
To prepare the solution, combine 20 g of sodium sulfate and 5 ml of sulfuric acid in water, then dilute to a final volume of 100 ml, adding a few drops of methyl red solution for color Ensure that the sealing liquid is saturated with carbon dioxide (CO2).
5.6.2.10 Calcium carbonate, CaCO3, dried to constant mass at (200 ± 10) °C
5.6.3.2 Apparatus for the determination of the carbon dioxide (alternative method)
1 dropping funnel with a volume of 100 ml
6 decomposition flask with a volume of 50 ml
7 absorption vessel with a volume of 100 ml containing potassium hydroxide solution (5.6.2.9) fitted with trap
8 burette with a volume of 100 ml
9 levelling vessel with a volume of 500 ml with sealing liquid (5.6.2.8)
10 jacketed tube filled with water
Figure 2 — Typical apparatus for determination of carbon dioxide (alternative method)
The mass of the building lime sample is determined by the expected CO₂ content, with specific amounts recommended for different ranges: 2 g for CO₂ levels between 0% and 2%, 1 g for levels exceeding 2% up to 5%, 0.5 g for levels above 5% to 10%, 0.3 g for levels from 10% to 15%, 0.2 g for levels between 15% and 40%, and 0.1 g for CO₂ levels exceeding 40% up to 50%.
Weigh out the sample accurately to 0,001 g (m 10) into the decomposition flask, add a spatula-tip of copper sulfate (5.6.2.4) to bind any hydrogen sulfide formed and suspend in a little water
Connect the flask to the apparatus using a double-bored stopper, ensuring that a funnel and feed tube to the measuring burette are inserted Open the stopcocks for both lines and adjust the three-way tap to link the flask and measuring burette Fill the burette with sealing liquid up to the three-way tap by elevating the levelling bottle Close stopcock 1 and fill the funnel with dilute hydrochloric acid, then add the acid to the flask until it is half full, leaving some acid as sealing liquid in the funnel with stopcock 1 closed.
Allow the mixture to react in a cold environment for a few minutes before heating it to the boiling point and boiling for an additional three minutes Use a dropping funnel to fill the flask completely with dilute hydrochloric acid (5.6.2.2) up to stopcock 2, ensuring that no acid overflows Close the burette with a three-way tap, and after five minutes, equalize the sealing liquid levels in the burette and leveling bottle before recording the gas volume \( V_7 \).
To connect the measuring burette with the absorption vessel, turn the three-way tap and wash out the air/CO₂ mixture collected Raise the levelling bottle to force all gas through the potassium hydroxide solution in the absorption vessel, allowing CO₂ to be absorbed Repeat this absorption process seven to eight times until only the residual gas remains in the measuring burette Finally, close the three-way tap, equalize the sealing liquid levels in the burette and levelling vessel, and record the volume \( V_8 \).
The difference in volume (V 7 – V 8 ) corresponds to the carbon dioxide content of the sample
Weigh 0,1 g of calcium carbonate (5.6.2.10) to an accuracy of 0,001 g into the decomposition flask Carry out the determination as described in 5.6.4
The volume difference (V 9 – V 10 ) corresponds to the carbon dioxide content of the calibration material
Calculate the correction factor F 1 of the absorption apparatus from the following relationship, obtained by rearranging Equation (9):
The meanings of the symbols correspond to those given in 5.6.6
The factor shall be in the range 1,00 to 1,04, otherwise check the apparatus for tightness and proper functioning and repeat the calibration
5.6.6 Evaluation and expression of results
Calculate the carbon dioxide content as CO 2 in mass fraction in percent from the following equation:
F 1 is the correction factor in accordance with 5.6.5;
V 7 is the volume of the gas before absorption, in millilitres;
V 8 is the volume of the gas after absorption, in millilitres;
P is the corrected barometer reading, in pascals × 100;
T is the measurement temperature, in kelvins; m 10 is the mass of the sample, in grams
When calibration and determination are performed consecutively, temperature and atmospheric pressure can be disregarded In this scenario, Equation (10) is simplified.
− ⋅ (11) if 0,1 g of CaCO 3 is weighed out for the calibration.
Loss on ignition
The method is used to determine the loss on ignition in building lime
The loss on ignition of the materials concerned is determined at (1 050 ± 25) °C
5.7.3.2 Electric furnace, capable of being maintained at (1 050 ± 25) °C, with a thermoelectric temperature indicator
5.7.3.5 Unglazed porcelain or platinum crucible
5.7.4.1 Hydrated lime and lime with hydraulic properties
Weigh 5 g (± 0.1 g) of the sample (m₁₁) in a pre-weighed crucible to the nearest 0.001 g Heat the sample in a furnace at 1,050 °C (± 25 °C) for 2 hours After removing the crucible from the furnace, cover it to prevent the absorption of carbon dioxide and water vapor Allow it to cool to room temperature in a desiccator and then weigh it again (m₁₂).
5.7.4.2 Milk of lime and lime putty
The water content of the milk of lime shall be determined as specified in 5.4.4.2 After drying the sample this way, the determination shall be carried out as specified in 5.7.4.1
5.7.5 Evaluation and expression of results
The loss on ignition expressed as LoI in mass fraction in percent is given by the following equation:
= − ⋅ (12) where m 11 is the mass of the sample before ignition at (1 050 ± 25) °C, in grams; m 12 is the mass of the sample after ignition at (1 050 ± 25) °C, in grams.
Available lime
The method serves to determine the available lime content:
in calcium lime in the form of quicklime and hydrated lime;
in calcium lime in the form of milk of lime and lime putty (in dry substance after drying as described in 5.4.4.2); and
in all types of lime with hydraulic properties
The suspended samples of lime with hydraulic properties shall be filtered for the titration
This method identifies the specific constituents involved in the reaction under defined conditions The interpretation of the results obtained will be based on this limiting definition.
The sample is mixed with water to slake and disperse it, preventing calcium oxide agglomeration that can cause incomplete suspension of quicklime To achieve this, the lime is heated The solubilization of lime occurs through a reaction with sugar, resulting in calcium sucrate, which is subsequently quantified by titration with hydrochloric acid, using phenolphthalein as the indicator.
5.8.3.1 Hydrochloric acid, standard volumetric solution, c (HCl) = 1 mol/l
5.8.3.2 Sodium hydroxide solution, c (NaOH) = 0,1 mol/l
Dissolve 0,5 g of phenolphthalein in 50 ml of ethanol (5.8.3.4) and dilute to 100 ml with water
5.8.3.5 Water, freshly boiled to remove CO 2 and cooled
5.8.3.6 Sucrose, refined sugar, commercially available
To prepare a 40% (w/v) solution, mix refined sugar with CO₂-free water in a large beaker and stir until fully dissolved Incorporate several drops of phenolphthalein indicator solution, then gradually add NaOH solution while stirring until a faint pink color remains For convenience, a stock solution of sugar can be created, but it should not be stored for more than two days Alternatively, the acidity of each batch of sugar can be measured, allowing for a correction in the titration process.
5.8.4.3 Heatable magnetic stirrer, with magnetic rod
Weigh 1 g of quicklime (± 0.1 g) with precision to the nearest 0.001 g and promptly transfer it to a 500 ml Erlenmeyer flask containing approximately 100 ml of water Cover the flask with a watch glass and heat the mixture on a magnetic stirrer until it reaches a boil, stirring continuously for 5 minutes After boiling, spray the walls of the flask with about 50 ml of water Remove the flask from the heat, loosely stopper it, and place it in a cold-water bath to cool to room temperature.
Weigh 1.3 g of hydrated lime, milk of lime, lime putty, or hydraulic lime (with a tolerance of ±0.1 g) to the nearest 0.001 g, and promptly transfer it to a 500-ml Erlenmeyer flask filled with approximately 150 ml of water.
To prepare the sample, add 50 ml of the neutralized sugar solution, or alternatively, mix 20 g of pure sugar with 40 ml of water, into the flask Seal the flask and shake the mixture for approximately 10 minutes, allowing for a reaction time of ± 2 minutes.
Remove stopper, add four to five drops of phenolphthalein indicator solution and wash down the stopper and sides of the flask with water
To achieve decolouration, gradually add hydrochloric acid from a 50-ml burette at a rate of 12 ml/min until the solution turns colourless After stirring for 60 seconds without additional acid, continue titrating dropwise at 4 ml/min until decolouration occurs, disregarding any temporary red coloration that may reappear.
5.8.8 Determination for lime with hydraulic properties
To filter the suspension, utilize a Buchner funnel with two fine filter papers that have a mean pore diameter of approximately 2 µm and an ash content of less than 0.01% After filtering, rinse both the flask and the filter with water Finally, titrate the filtrate with hydrochloric acid, using phenolphthalein as the indicator.
5.8.9 Evaluation and expression of results
The available lime content, represented as available CaO for quicklime or available Ca(OH)₂ for other products, is expressed as a mass fraction in percent and can be calculated using specific equations for quicklime.
V = × × × × (13) for all other products: available Ca(OH) 2 14 14
The volume of hydrochloric acid utilized is denoted as V, measured in millilitres The mass of the calcium oxide (CaO) product is represented by m₁₃, expressed in grams, while the mass of the calcium hydroxide (Ca(OH)₂) product is indicated by m₁₄, also in grams.
Particle size by dry sieving
This method is used for the determination of the particle size distribution It applies to quicklime according to
The test involves using a series of sieves to classify a material into various particle size categories, with sizes decreasing progressively The selection of aperture sizes and the number of sieves is based on the specifications outlined in Tables 5 and 12 of EN 459-1:2010.
The mass of particles collected on different sieves correlates with the initial mass of the material, and the cumulative percentages that pass through each sieve are documented numerically (refer to Annex A).
6.1.3.1 Test sieves, aperture sizes 10,0 mm, 5 mm and 2,0 mm
6.1.3.2 Tightly fitting pan and lid, for the sieves
6.1.3.3 Trays or other suitable containers, of sufficient size to contain the test portion
Samples shall be reduced by means of a sample divider (6.1.3.6) The mass of each test portion shall be recorded
Pour the sample into the sieving column, which consists of several sieves stacked in descending order of aperture sizes, along with a pan and lid.
To ensure no material is lost during the sieving process, shake the column either manually or mechanically, and then carefully remove the sieves one at a time, starting with the largest aperture size Use a pan and lid to collect the material from each sieve as you shake it manually.
Transfer all the material which passes each sieve onto the next sieve in the column before continuing the operation with that sieve
Weigh the material retained on the sieve with the largest aperture size and note its mass as R1 Repeat this process for each subsequent sieve, recording the retained mass as R2 or R3 accordingly.
Weigh the screened material remaining in the pan and record its mass as P This material is sieved following the air-jet sieving method in 6.2
6.1.6 Evaluation and expression of results
Record the various masses on a test data sheet, an example of which is given in Annex A
Calculate the mass retained on each sieve as a m (P i ) in mass fraction in percent of the original mass M 1 using the following equation:
M 1 is the mass of the test portion, in grams;
R i is the mass of the residue retained on the test sieves, in grams
Calculate the cumulative percentage of the original mass retained on each sieve down to the 0,09 mm sieve inclusive
Calculate the cumulative percentage of the original mass passing each sieve down to the 0,09 mm sieve inclusive.
Particle size by air-jet sieving
This method assesses the retention of particles that pass through a 2.0 mm test sieve, allowing for the determination of particle sizes in agglomerates of very fine particles It employs test sieves with aperture sizes of 0.2 mm and 0.09 mm.
This method applies to hydrated lime, all types of lime with hydraulic properties and quicklime according to
6.2.2.1 Air-jet sieving apparatus, of the general form shown in Figure 3
The apparatus shall be set to give a pressure difference of 2 kPa to 2,5 kPa across the sieves
6.2.2.2 Test sieves, 200 mm diameter, aperture sizes 0,2 mm and 0,09 mm
The effective functioning of certain air-jet apparatus may necessitate the use of non-standard sieve frames and extra gaskets This is acceptable as long as the sieving medium and overall construction method adhere to the specified standards.
6.2.2.3 Trays or other suitable containers, of sufficient size to contain the test portion
6.2.2.6 Ultrasonic cleaning bath, for cleaning the mesh of the sieves
6.2.2.7 Mallet, if there is a tendency for material to adhere to the lid of the apparatus
A rubber or plastic tipped mallet is preferred
6.2.2.8 Drying oven (optional), thermostatically controlled to maintain a temperature of (105 ± 5) °C
12 pressure gauge socket, with dust hood
Figure 3 — Typical apparatus for air-jet sieving
Weigh the building lime sample accurately to the nearest 0.001 g (m 15) Install a test sieve with a 0.09 mm aperture into the apparatus and carefully transfer the entire test portion onto the sieve mesh, ensuring no loss of material.
Ensure the lid is securely fitted and activate the apparatus, verifying that the vacuum level exceeds the manufacturer's minimum requirement and that the slit nozzle is functioning correctly If any material sticks to the lid, lightly tap the center with a mallet Should agglomeration occur due to the air-jet, pause the sieving process and use a soft brush to break up the clumps, being careful not to force particles through the sieve.
After (5 ± 0.2) minutes, turn off the apparatus and gently take out the sieve Move the retained material into a tray or appropriate container Use a soft brush to clean the sieve mesh over the tray Weigh the residue, including the material brushed from the sieve, and record the mass to the nearest 0.001 g.
Reinstall the sieve into the apparatus and return all residue to the sieve mesh Continue the weighing and sieving process until the sieving end-point is reached, recording the final mass to the nearest 0.001 g The sieving end-point is determined when no more than 0.2% of the original test portion's mass passes through the sieve within one minute.
To determine the sieving end-point, fit the 0.20 mm test sieve into the apparatus and conduct the weighing and sieving stages repeatedly until the mass of the residue indicates that the end-point has been achieved Ensure to record the final mass to the nearest 0.001 g.
6.2.4 Evaluation and expression of results
The mass retained on each sieve expressed as m (P 0,20 or 0,09) in mass fraction in percent is given by the following equation:
P m m = × (16) where m 15 is the mass of the dry substance in the test portion, in grams; m 16 is the mass of the residue retained on the test sieves, in grams.
Bulk density
To determine bulk density, a specific apparatus is required, which includes a one-litre cylindrical vessel, a connecting piece with a closure flap, and a hopper equipped with a sprung closure lever The lever operates the closure flap, enabling the sieved material in the hopper to be released into the one-litre vessel.
Table 2 — Dimensions of density apparatus
Part No Part name Dimension
Internal diameter d 1 : (87 ± 1) mm Internal height h 1 : corresponding to filled contents of 1 000 cm 3 , limit of error = ± 5 cm 3
Internal diameter, bottom d 3 : (79 ± 1) mm Internal diameter, top d 4 : (99 ± 1) mm
1 cylindrical 1 l vessel, see Table 2 for the dimensions of h 1 and d 1
2 connecting piece, see Table 2 for the dimensions of h 2 and d 2
4 hopper, see Table 2 for the dimensions of h 3 and d 3
Figure 4 — Typical apparatus for the determination of bulk density 6.3.2 Procedure
To measure the density of building lime, fill the hopper of the density apparatus with the lime sample until it reaches its natural angle of repose Open the closure flap using the lever and wait for 2 minutes Afterward, remove the hopper, level off the excess lime powder in the vessel with a ruler, and record the mass of the contents.
Conduct the test three times using a fresh sample of lime powder for each trial If the resulting values differ by more than 10 g, repeat the tests twice Calculate the average of the three values that show the least deviation to determine the bulk density of the lime powder, and report this value in kilograms per cubic decimetre.
Soundness
Due to the diverse chemical and physical properties of building limes, a single method cannot be used to assess their soundness universally Therefore, it is essential to evaluate the soundness of each type of lime through specific testing methods.
hydrated calcium lime and all types of lime with hydraulic properties 6.4.2.1 (Reference method)
hydraulic lime with an SO 3 content of more than 3 % up to 7 % 6.4.2.3
hydrated calcium lime, lime putty and hydrated dolomitic lime which include grains larger than 0,2 mm
quicklime, lime putty, dolomitic lime and hydrated dolomitic lime 6.4.4
6.4.2 For hydrated calcium lime and all types of lime with hydraulic properties
Incomplete slaking of lime results in the steam hydration of calcium oxide (CaO) in a disc-shaped specimen, causing expansion that can be measured by changes in the disc's diameter.
6.4.2.1.2.1 Moulds, as shown in Figure 5
The piston shall have a milled cross groove on its end that forms the surface of the specimen
6.4.2.1.2.2 Press, capable of applying a 2 kN force to the piston of the mould
The force should be accurate to the nearest 0,5 kN Alternatively, the pressure from the piston (1) on the specimen in the mould (Figure 5) may be controlled using a pressure gauge
6.4.2.1.2.3 Length measuring device, capable of measuring to the nearest 0,1 mm
6.4.2.1.2.4 Steam cabinet, for the steam treatment of the specimens
A basic assembly features a cylindrical tank with a perforated disc, such as stainless wire gauze or a sieve, which holds specimens about 50 mm above boiling water The lid is designed to prevent condensed water from dripping onto the specimens.
6.4.2.1.2.5 Heating source, which enables the water to be kept at boiling point, such as an electric hot plate fitted with a regulator or an adjustable gas burner
6.4.2.1.2.6 Balance, for weighing to approximately 0,001 g
Tolerances in accordance with ISO 2768-m
Figure 5 — Typical specimen mould 6.4.2.1.3 Procedure
Weigh 25 grams of the building lime to be tested, with an accuracy of ± 0.1 g Add enough water to ensure the specimen can be handled after demoulding, typically around 5 g, but use less than 2.5 g for lime with hydraulic properties, and mix thoroughly.
For optimal results, it is advisable to work directly in the specimen mould when the balance permits If direct work is not feasible, use an intermediate container and ensure the mixture is transferred to the specimen mould as completely as possible Finally, position the mould with the inserted piston under the press.
Apply a force of up to 2 kN and maintain this pressure for about 5 seconds before demoulding The resulting specimen typically measures around 10 mm in thickness and 50 mm in diameter Measure two diameters to an accuracy of approximately 0.1 mm, such as across the cross-diameter, and calculate \(D_i\) as the average of these measurements Place the specimen in a steam cabinet for 90 minutes, exposed to steam from boiling water After removal, allow the specimen to cool below 40 °C, and then calculate \(D_e\) as the average of the two measurements taken post-steaming.
The value of expansion, expressed in millimetres to the nearest 0,1 mm, is given by the difference (D e – D i )
Perform the soundness test as per EN 196-3, but for class 5 hydraulic lime, ensure that the molded specimens are pre-cured for (48 ± 0.5) hours at a minimum relative humidity of 90% and a temperature of (20 ± 1) °C.
The following modifications shall apply for CL 70, CL 80, CL 90, and lime with hydraulic properties of classes
Use a steam cabinet in place of the water bath and humidity cabinet described in EN 196-3
To prepare three test specimens, hand mix 75 g of dry hydrated lime with 20 ml of water Fill each mould loosely with the mixture, lightly tamping to eliminate air pockets, and continue until the mix is level with the top of the mould.
Where this procedure is not appropriate to fill the mould according to EN 196-3, the amount of water may be altered and the quantity used reported
Measure the distance (A) separating the ends of the indicator points to the nearest 1 mm Transfer the moulds immediately to the steam cabinet which should be boiling vigorously
Subject the moulds to the continuous action of steam at atmospheric pressure for a period of (180 ± 10) min
At the end of this time remove the moulds, allow to cool to room temperature and measure the distance (B) separating the ends of the indicator points
For each specimen record the measurements A and B and calculate the differences (B – A) in millimetres to the nearest 1 mm
If individual results differ by more than 2 mm repeat the test
6.4.2.3 For hydraulic lime with an SO 3 content of more than 3 % and up to 7 % (cold water test) 6.4.2.3.1 Preparation of specimens
To prepare a stiff paste with 200 g of hydraulic lime, knead it thoroughly with 45 g to 90 g of water for 3 minutes The correct water amount is indicated when the paste spreads slowly after shaking the glass plate several times.
To create two cakes, place lumps of the paste onto the center of two lightly oiled flat glass plates and gently shake the plates until the cakes reach a height of 50 mm.
70 mm in diameter and about 10 mm thick are formed After spreading, the cakes shall not be worked with a knife or trowel
The two cakes are intended for the duplicate determination
After preparation, place the two cakes in a moist air storage cabinet with a relative humidity of at least 90% to allow them to harden undisturbed After approximately 24 hours, carefully detach the cakes from the glass plate and immerse them in water at a temperature between 18 °C and 21 °C for further observation.
27 days If warping or gaping edge cracks appear, by themselves or together with netted cracks, this indicates
"blowing", i.e the cake splits with gradual loosening of the cohesion originally obtained, which can lead to complete disintegration (see Figure 8)
The curvature of the bottom surface of the cake may have a camber of not more than 2 mm
The blowing phenomenon is frequently found on the cakes after only three days; nevertheless observation for up to 28 days suffices to recognize blowing reliably
The cake may be taken out of the water for observation for not more than 30 min, since otherwise radial shrinkage cracks can readily form on the edges (Figure 7)
6.4.3 For hydrated calcium lime, lime putty and hydrated dolomitic lime which include grains larger than 0,2 mm
Using large particles of overburnt quicklime in plastering can lead to issues like popping and pitting In this test, hydrated calcium lime is mixed with a non-retarded plaster of Paris, and once the plaster sets, it is exposed to steam This steam hydrates any unreacted calcium or magnesium oxide, resulting in expansion and the eruption of the plaster surface.
6.4.3.2.1 Large sheet of non-absorptive material for mixing (a glass plate 500 mm × 750 mm has been found to be suitable)
Three brass ring moulds, each with an internal diameter of 100 mm and a depth of 5 mm, feature an annular thickness of at least 5 mm and an internal taper of approximately 5° Each mould is equipped with a non-porous base plate.
6.4.3.2.5 Steam cabinet, in which soundness specimens can be submitted to the action of steam at atmospheric pressure
The lid shall be designed so that condensed water does not drip onto the specimens
Plaster of Paris, containing more than 90 % by mass of calcium sulfate hemihydrate (CaSO 4 1/2 H 2 O) and passing the 0,2 mm sieve
When mixed with 50% of its own mass of water at a temperature of (20 ± 2) °C, the material must demonstrate an initial setting time of at least 4 minutes and no more than 15 minutes, as tested according to section 6.5.
Weigh about 250 g of the sample with an accuracy of 1 g and mix it with enough water using two palette knives to create lime putty at a temperature of (20 ± 2) °C on a large non-absorptive sheet Form the mixture into a compact mass, cover it to prevent water loss, and let it stand for (120 ± 10) minutes Apply petroleum jelly to grease the three ring molds and base plates.
Setting times
The setting time is determined by observing the penetration of a needle into building lime paste of standard consistence until it reaches a specified value
Lime paste with standard consistency exhibits a defined resistance to penetration when tested with a standard plunger The optimal water content for this paste is established through trial penetrations of various pastes with differing water levels.
The laboratory in which specimens are prepared and tested shall be maintained at a temperature of
(20 ± 2) °C and a relative humidity of not less than 50 %
Daily monitoring of air temperature and relative humidity in the laboratory, along with the water temperature in storage containers, is essential and should be conducted at least once during working hours.
Building lime, water and apparatus used to make and test specimens shall be at a temperature of (20 ± 2) °C
Where temperature ranges are given, the target temperature at which the controls are set shall be the middle value of the range
6.5.2.2.1 Balance, capable of weighing to the nearest ± 1 g
6.5.2.2.2 Graduated cylinder or burette, capable of dispensing to an accuracy of ± 1 ml
6.5.2.2.4 Water, distilled or deionized water shall be used for making, storing and boiling specimens
6.5.2.2.5 Building lime, water and apparatus used to make and test specimens shall be at a temperature of
NOTE Other water may be used provided that it can be shown to give the same test results
The Vicat apparatus, illustrated in Figures 9a) and 9b), utilizes a plunger depicted in Figure 9c) This plunger must be made of non-corrodible metal, shaped as a right cylinder with a minimum effective length of 45 mm and a diameter of (10.00 ± 0.05) mm The total mass of the moving components should be (300 ± 1) g, ensuring that their movement is perfectly vertical, free from significant friction, and aligned with the axis of the plunger.
The Vicat mould used for testing building lime paste must be made of hard rubber, plastic, or brass, and should preferably have a truncated conical shape It should measure 40.0 ± 0.2 mm in depth and have an internal diameter of 75 ± 10 mm The mould must be sufficiently rigid and equipped with a base-plate that is larger than the mould itself, at least 2.5 mm thick, and made from impermeable materials resistant to the building lime paste, such as plain glass.
NOTE Moulds of other metal may be used provided that they are of the specified depth and that their use has been calibrated against the specified mould
Dimensions in millimetres a) Side view with mould in upright position for initial setting time determination b) Front view with mould inverted for final setting time determination
6 view from below needle with attachment for determining final setting time
The manual Vicat apparatus is commonly used to determine the standard consistency and setting time of building lime It includes a plunger for assessing standard consistency, as well as needles for measuring both the initial and final setting times.
6 view from below needle with attachment for determining final setting time
Figure 9 (continued) — Typical manual Vicat apparatus for determination of standard consistence and setting time of building lime
NOTE Only one correcting weight is required for each Vicat apparatus if the mass of the plunger and the needles with and without the attachment is always the same e.g (9,0 ± 0,5) g.
6.5.3.2.1 Mixing the building lime paste
Weigh 500 g of building lime to the nearest gram and measure 125 g of water using a graduated cylinder or burette, then add the water to the mixer bowl.
To ensure optimal mixing, carefully add building lime to the water, taking between 5 to 10 seconds for the process Mark the start of this addition as zero time for future time measurements Immediately after, operate the mixer at a low speed for 90 seconds.
After 90 seconds of operation, pause the machine for 30 seconds to scrape off any paste clinging to the bowl outside the mixing zone and return it to the mix Then, restart the machine and continue running it at a low speed.
90 s The total mixer running time shall be 3 min
NOTE Any other mixing method, whether by machine or hand, may be used provided that it can be shown to give the same test results as the specified method
Immediately transfer the paste to the mould positioned on a lightly greased glass base-plate, filling it generously without excessive compaction or vibration Use a straight-edged tool to gently saw off the excess, ensuring the paste remains level with the mould and has a smooth upper surface.
To calibrate the Vicat apparatus, attach the plunger and lower it onto the base-plate, adjusting the pointer to zero After leveling the paste, position the mould and base-plate centrally under the plunger Gently lower the plunger until it contacts the paste, pausing for 1 to 2 seconds to prevent initial velocity Release the plunger quickly to allow it to penetrate the paste, ensuring this occurs 4 minutes ± 10 seconds after zero time Record the scale reading when penetration stops or 30 seconds after release, whichever comes first.
Record the scale reading, which shows the distance from the bottom of the plunger to the base plate, along with the water content of the paste expressed as a percentage of the mass of the building lime Clean the plunger promptly after each penetration.
Conduct the test using pastes with varying water contents until you identify one that achieves a distance of (6 ± 2) mm between the plunger and the base plate Document the water content of this paste to the nearest 0.5% as the standard consistency water content.
6.5.4.1.1 Room or humidity cabinet, of adequate size and maintained at (20 ± 1) °C and a relative humidity of not less than 90 %
6.5.4.1.2 Vicat apparatus for initial set
Replace the plunger with a steel needle, designed as a right cylinder with a minimum effective length of 45 mm and a diameter of (1.13 ± 0.05) mm The total mass of the moving components should be (300 ± 1) g, ensuring that their movement is perfectly vertical, free from significant friction, and aligned with the needle's axis.
Automatic setting time machines are available for commercial use, provided they demonstrate equivalent test results to the specified apparatus and procedures.
6.5.4.2 Determination of initial setting time
To calibrate the Vicat apparatus, first lower the needle onto the base-plate and adjust the pointer to zero on the scale After calibration, raise the needle to the stand-by position.
Fill a Vicat mould with paste of standard consistence and level it, in accordance with 6.5.3.2.1 and 6.5.3.2.2