BUILDING & MANAGEMENT VOLUME 3 ISSUE 2 MAY- AUGUST 2019
DECLARATION OF PERFORMANCE( DOP) AND CE MARKING OF CEMENT MORTARS MADE WITH RECYCLED STEEL WASTE
I. SANTAMARÍA-VICARIO, S. GUTIÉRREZ-GONZÁLEZ, V. CALDERÓN-CARPINTERO AND A. RODRÍGUEZ-SAIZ( 2019). BUILDING & MANAGEMENT, 3( 2): 06-15
filtrate was acidified by adding 20 ml of diluted nitric acid( 1 + 2) and brought to boiling point.
By means of a pipette; 5 ml of the solution of silver nitrate 0.10 mol / l was added to the acidified solution. It was immediately brought to boiling point for 1.5-2 min; and left to cool to a temperature below 25 º C. The contents of the beaker were passed to a 500 ml Erlenmeyer flask. 5 drops of the indicator solution of ammonium sulphate and iron III [ NH4Fe( SO4) 2 · 12H2O ] are added.
A 10 ml burette is filled with an ammonium thiocyanate solution. The solution of the burette in the previous mixture is added; turning a light brownish-red colour; which disappears under vigorous agitation. The test ends when the colour is remained visible following agitation( Fig. 3). The volume; V1; of the solution of ammonium thiocyanate solution consumed in the assay was noted.
To do so, the procedure described in EN 1052-3 [ 22 ] was followed. The sample specimens consisted of three bricks with mortar bonds placed on a larger surface, as shown in Fig 4. Double hollow bricks with dimensions of( 240x110x90) mm and with a water absorption coefficient to saturation of 18 % were used.
To prepare the sample specimens, three ceramic bricks, previously dried in an oven, were placed in water for 1 min. Within that time, the bricks had absorbed 9 % of water, so that they presented a known humidity level that had not reached saturation point, but that avoided absorbing the mortar mixing water.
The previous procedure was repeated without the mortar sample and the volume; V2; of the solution of ammonium thiocyanate necessary for this assay was noted.
The content of chloride ions; expressed by mass % in reference to the sample of dry mortar was calculated by means of the following equation:
3.545 Cl( I)% =( V2 −V1)
� f � 10� m
( 1)
Where:
V1 is the volume of the ammonium thiocyanate solution; 0.1M( ml); consumed during the assay of the test solution.
V2 is the volume of the ammonium thiocyanate solution; 0.1M( ml); consumed in the dummy assay.
m is the mass of the test sample( gr)
f is the molarity factor in relation to the solution of ammonium thiocyanate( usually 0.10 mol / l)
Figure 3. Operating procedure. Calculation of the water-soluble chloride content.
6.2. DETERMINATION OF SHEAR STRENGTH
CE-markings of the masonry mortars that will be employed for masonry walls need to include the characteristic shear strength.
Figure 4. Operating procedure. Preparation and breakage of sample specimens under shear stress
Having prepared the samples, they were placed in a polyethylene bag and compressed, with a mass uniformly distributed, to give a vertical tension of between 2x10-3 N / mm 2 and 5x10-3 N / mm 2, in accordance with the specifications of the harmonized standard. The specimens remained unaltered over a period of 28 days in a humid chamber, under a constant temperature of 20 º C and a relative humidity of 95 %. At the end of the curing period, the specimens were tested in a Suzpecar model MEn 101 multitest machine, with a load capacity of 20 tn.‘ Procedure B’, detailed in the standard and shown in Fig 4 was followed.
The initial shear stress, fvoi, was calculated with the following expression( 2): f voi = F i
2A i
( 2)
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