Методи випробувань стінових каменів. Частина 3. Визначення в керамічних виробах середньої густини і пористості методом гідростатичного зважування

1 2 3 4 ^a 1 2 3 4 5 O 6 7 8 9 CONTENTS
page
Foreword V
1 Scope 1
2 Normative references 1
3 Principle 1
4 Symbols 2
5 Apparatus 2
6 Sampling 2
7 Test procedure 2
8 Calculation and expression of
results 3
9 Test report 3 EN 772-3:1998 - - - - 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of an identical text or by endorsement, at the latest by May 1998,and conflicting national standards shall be withdrawn at the latest by August 1998.
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 3: Determination of net volume and percentageof voids of clay masonry units by hydrostatic weighing

1 2 EN 771-1 EN 772-16 3 1 SCOPE

This European Standard specifies a method of determining the net volume of and percentage of voids in clay masonry units (including frogs and cells).

2 NORMATIVE REFERENCES

This European Standard incorporates by dated or undated reference, provision from other publications. The 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 772-16 Methods of test for masonry units - Part 16: Determination of dimensions

3 PRINCIPLE

The principle of this test is to obtain the net volume of the masonry unit by weighing in air and weighing in water and to subtract this from the gross volume, obtained by measurement of its dimensions, to obtain the volume of voids.
4 M wu M au l u w u 0 h u V gu V ua V nu 5 5.1 5.2 6 7 4 SYMBOLS
M wu is the apparent mass of the specimen in water, (g)
M au is the mass of the specimen in air, (g)
l u is the length of the specimen, (mm)
w u is the width of the specimen, (mm)
h u is the height of the specimen, (mm)
V gu is the gross volume of the specimen,
(mm 3 )
V ua is the volume of voids in the specimen,
(mm 3 )
V nu is the net volume of the specimen,
(mm 3 )
0,001 g/mm 3 )

5 APPARATUS

5.1 A tank with adequate capacity to submerge a whole masonry unit.
5.2 A weighing instrument capable of weighing whole masonry units with an accuracy of at least 0,1 % of their mass when dry.

6 SAMPLING

The method of sampling shall be in accordance with EN 771-1. 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 TEST PROCEDURE

Measure the length ( l u ), width ( w u ) and height ( h u ) of the specimen in accordance with EN 772-16. Immerse the specimen in water (5.1) for at least 1 hour. When the apparent masses ( M wu ), measured by two successive weighings at 30 min intervals, differ by less than 0,2 % remove the specimen from the water and record the result of the second weighing as the apparent mass ( M wu ). Remove surface water with a damp towel and determine the weight ( M au ) immediately.

8 8 CALCULATION AND EXPRESSION

OF RESULTS

Calculate the net volume of the specimen ( V nu ) by subtracting the mass of the specimen obtained by weighing it under water from that obtained when weighing it in air ( M au - M wu ) dividing it by the density of water( p w ). Express the net volume of the specimen to the nearest 10 4 mm 3 as f _ M au - M wu nu —
p w
Determine the mean value of net volume determinations to the nearest 10 4 mm 3 . Calculate the gross volume of the specimen ( V gu ) by multiplying the length ( l u ) by the height ( h u ) and width ( w u ) of the specimen measured in accordance with EN 772-16 to the nearest 10 4 mm 3 .
V gu - I u w u h u . Calculate the volume of voids ( V vu ) by
V vu - V gu V nu .
V vu- x 100.
V gu
Determine the mean value, if required to the near-

9 9 TEST REPORT - - - - - - - - - the number, title and date of issue of this European Standard,
- the name of the organization that carried out the sampling and the method used,
- the date of testing,
- the type, origin and designation of the masonry unit by reference to EN 771-1,
- the number of specimens in sample,
- the net volume of each specimen and the mean value to the nearest 10 4 mm 3 ,
- the percentage of voids of each specimen and the mean value, if required, to the nearest 1 %,
- remarks, if any. **********