1 2 3 4
IV
V Foreword V
1 1 Scope 1
1 2 Normative references 1
2 3 Principle 2
2 4 Definitions and symbols 2
3 5 Apparatus 3
3 6 Sampling 3
4 7 Procedure 4
6 8 Test report 6 EN 772-13:2000 - - - FOREWORD
This European Standard has been prepared by Technical Committee CEN/TC 125 "Masonry", the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by December 2000, and conflicting national standards shall be withdrawn at the latest by December 2000.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.
^AЦ?IO^AЁ?Ь?^И?Й? Methods of test for masonry units - Part 13:
Determination of net and gross dry density of masonry units (except for natural stone) 1 2 EN 771-1 EN 771-2 EN 771-3 EN 771-4 EN 771-5 1 SCOPE
This European Standard specifies a method of determining the net and gross dry density of masonry units (except for natural stone masonry units).
2 NORMATIVE REFERENCES
This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies.
EN 771-1 Specification for masonry units - Part 1: Clay masonry units;
EN 771-2 Specification for masonry units - Part 2: Calcium silicate masonry units;
EN 771-3 Specification for masonry units - Part 3: Aggregate concrete masonry units (dense and lightweight aggregates);
EN 771-4 Specification for masonry units - Part 4: Autoclaved aerated concrete masonry units;
EN 771-5 Specification for masonry units - Part 5: Manufactured stone masonry units;
prEN 772-3 prEN 772-9 EN 772-16 3 4 B 4.1 B 4.1.1 cepe 4.1.2 4.1.3 4.1.4 4.2 l u - w u - 0 h u - m o, u - 0 m o,p, tot — m dryp — prEN 772-9 Methods of test for masonry units - Part 9: Determination of volume and percentage of voids and net volume of calcium silicate masonry units, by sand filling;
EN 772-16 Methods of test for masonry units - Part 16: Determination of dimensions.
3 PRINCIPLE
After drying to constant mass and calculating the net and gross volume, the net and gross dry density of the masonry units are calculated.
4 DEFINITIONS AND SYMBOLS
4.1 Definitions
4.1.1 gross dry density - the mass per unit gross volume after drying to constant mass.
4.1.2 gross volume - the volume of the unit derived from the length, width and height with a deduction of the volume of perforations, voids, recesses or indentations intended to be filled with mortar.
4.1.3 net dry density - the mass per unit net volume after drying to constant mass.
4.1.4 net volume - the gross volume of the unit less the volume of any perforations or voids not intended to be filled with mortar.
4.2 Symbols
l u is the unit length, (mm)
w u is the unit width, (mm)
h u is the unit height, (mm)
m o,u is the mass of a whole unit specimen prior to drying, (g)
m o,p,tot is the combined mass of a group of three representative portions of a whole unit specimen prior to drying, (g)
m dry,p is the mass of one individual representative portion of the three portions of a whole unit specimen after drying to constant mass, (g)
m dry ,p, tot — m dry ,u — W p - V nu - V gu - V gp - 5 O 5.1 5.2 5.3 6 m dry,p,tot is the combined mass ofa group of three representative portions of a whole unit specimen after drying to constant mass, (g)
m dry,u is the mass of a whole unit specimen (or corresponding whole unit where representative portions have been taken) after drying to constant mass, (g)
W p is the moisture content of a group of
three representative portions ofa whole unit specimen
V n,u is the net volume of unit, (mm 3 )
V g,u is the gross volume of unit, (mm 3 )
V g,p is the gross volume of parts of units,
(mm 3 )
(kg/m 3 )
5 APPARATUS
5.1 Ventilated oven capable of maintaining a temperature of 105 5.2 Ventilated oven capable of maintaining a temperature of 70 5.3 Weighing instrument capable of weighing the whole unit or portions of itto an accuracy of 0,1 % of their mass.
6 SAMPLING
The method of sampling shall be in accordance with the relevant part of EN 771. The minimum number of specimens shall be six, but a larger minimum number may be specified in the product specification, in which case that larger number shall be used.
7 7.1 7.1.1 7.1.2 K
7 PROCEDURE
7.1 Determination of dry mass
7.1.1 Whole unit specimens
Dry the test specimens to constant mass m dry,u in a ventilated oven at a temperature of 70 Constant mass is reached, if during the drying process in two subsequent weightings with a 24 h interval, the loss in mass between the two determinations is not more than 0,2 % of the total mass. Record the mass m dry,u .
7.1.2 Portions of whole unit specimens
Where representative portions are used then first weigh each whole unit specimen and record the mass ( m o,u ). Then obtain three representative solid portions, i.e containing no enclosed or exposed formed voids, of at least 100 g from each whole unit specimen and weigh each group of three together. Record the mass of each group ( m o,p,tot ).
Dry each group of three portions to constant mass following the procedure of 7.1.1 above.
Record the mass of each group ( m dry,p,tot ).
Calculate the moisture content of each group of three portions using equation (1):
(1)
Calculate the corresponding dry mass of the whole unit (mdry,u) using equation (2):
m dry , u -
o , u
1 - w p
(2)
7.2 Cepe 7.2.1 b) 7.2 Net dry density
7.2.1 Whole units
Determine the net volume using one of the following methods as appropriate:
a) for clay masonry units, by weighing in water as indicated in prEN 772-3;
b) for calcium silicat e masonry units, by using sand filling as indicated in prEN 772-9;
c) d) B
7.2.2 B - - -
B c) for manufactured stone and solid aggregate concrete masonry units, by subtracting the volume of all recesses or indentations, determined using a suitable measuring device, from the volume (length d) for aggregate concrete masonry units with formed voids, by the method of c) above, but in addition subtracting the volume of all voids.
Express the net volume V n,u to the nearest 10 4 mm 3 .
Determine the net dry density of the masonry unit (3)
Calculate the net dry density of each whole unit specimen to the nearest 5 kg/m 3 for densities up to 1000 kg/m 3 and to the nearest 10 kg/m 3 for densities over 1000 kg/m 3 .
Calculate the mean of the net dry densities of the specimens.
7.2.2 Representative portions of whole unit specimens
Determine the net dry density of the parts as follows:
- determine the dry mass of each portion of the whole unit specimen m dry,p by drying according to 7.1.2;
- determine the volume of the parts V g,p by measuring length, width and height to the nearest 1 mm;
- calculate the net dry density (4)
Define the net dry density of each whole unit specimen (from which the portions were obtained) as the mean value of the net dry density of the three representative portions. Express the net dry density of the whole unit specimens to the nearest 5 kg/m 3 for densities up to 1000 kg/m 3
7.3 Ce m dry , u 8 а?) b) с?) d) e) f) h) і?) g) the individual and mean values of net dry density;
h) the individual and mean values of gross dry density;
i) remarks, if any. **********