KENYA STANDARD DKS2802-5:2018
ICS
Masonry units —Methods of test
Part 5:
Determination of volume and percentage of voids
and net volume of clay and calcium silicate
masonry units by sand filling
© KEBS 201 8 First Edition ,2018DKS2802-5:2018
ii ©KEBS 201 8—All rights reservedTECHNICAL COMMITTEE REPRES ENTATION
The following organizations were represented on the Technical Committee:
National Housing Corporation
Kenya Clay Products Ltd
Coast Clay Works Ltd
Consumer Information Network
University of Nairobi
Kenya Industrial Research & Development Institute
Architectural Association of Kenya
M&O Consulting Engineers
Kenya Association of Manufacturers,
Miritini Building Products Ltd .
Kenya National Federation of Jua Kali Association
Kenya Bureau of Standards —Secretariat
REVISION OF KENYA STANDARDS
In order to keep abreast of progress in industry, Kenya Standards shall be regularly reviewed.  Suggestions
for improvements to published standards, addressed to the Managing Director, Kenya Bureau of Standards,
are welcome.
© Kenya Bureau of Standards, 201 7
Copyright. Users are reminded that by virtue of Section 25 of the Copyright Act, Cap. 130 of 2001  of the Laws of Kenya, copy right subsists
in all Kenya Standards and except as provided under Section 25 of this Act, no Kenya Standard produced by Kenya Bureau of Standards
may be reproduced, stored in a retrieval system in any form or transmitted by any means without prior permission in writing f rom the
Mana ging Director.KENYA STANDARD DKS2802-5:2018
ICS
© KEBS 201 8—All rights reserved iiiMasonry units —Methods of test
Part 5:
Determination of volume and percentage of voids and
net volume of clay and calcium silicate masonry units by
sand filling
KENYA BUREAU OF STANDARDS (KEBS)
Head Office: P.O. Box 54974, Nairobi -00200, Tel.: (+254  020) 605490, 602350, Fax: (+254 020)  604031
E-Mail: info@kebs.org, Web:http://www.kebs.org
Coast Region Lake Region Rift Valley Region
P.O. Box 99376, Mombasa -80100 P.O. Box 2949, Kisumu -40100 P.O. Box 2138, Nakuru -20100
Tel.: (+254  041) 229563, 230939/40 Tel.: (+254 057) 23549, 22396 Tel.: (+254 051) 210553, 210555
Fax: (+254  041) 229448 Fax: (+254 057) 21814DKS2802-5:2018
iv ©KEBS 201 8—All rights reservedForeword
This Kenya Standard was prepared by the Clay and Clay Products Technical Committee under the guidance
of the Standards Projects Committee and in accordance with the procedures of the Kenya Bureau of
Standards.
During the development of this standard, reference was made to the following documents:
BS EN 772 -9,Methods of test for masonry units -Part 9: Determination of volume and percentage of
voids and net volume of clay and calcium silicate masonry units by sand filling.
Acknowledgement is hereby made for the assistance received from these sources .KENYA STANDARD DKS2802-5:2018
© KEBS 201 8—All rights reserved 1Masonry units —Methods of test
Part 5:
Determination of volume and percentage of voids and net volume of clay
and calcium silicate masonry units by sand filling
1 Scope
This Kenya Standard specifies a method of determining the volume and percentage of voids and net volume
of calcium silicate masonry units containing cells, frogs and holes .
2 Normative references
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.
DKS 2801 :1 Masonry Units —Specification —Part 1: Clay Masonry Units.
DKS 2802 :8 Masonry units —Test Methods —Part 8: Determination of dimensions.
3 Principle
The principle of this test is to measure the volume of voids in a masonry unit by measuring the volume of sand
required to fill them.
4 Symbols
Vn,uis the net volume of each unit (104mm3),
Vs,uis the volume of voids (104mm3),
Vg,uis the gross volume of each unit (104mm3),
5 Materials
Dry graded sand with a grain size above 0.5 mm and passing a 1 mm test sieve (6.4).
6 Apparatus
6.1 Thin sheet of foam rubber, or other resilient material .
6.2 Rigid plate , slightly larger than the unit.
6.3 Glass measuring cylinder , graduated in ml.
6.4 Two test sieves , one with 0.5 mm apertures and one with 1 mm apertures.
7 Preparation of specimens2 ©KEBS 201 8—All rights reserved7.1 Sampling
The method of sampling shall be in accordance with DKS 2801:1 .  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.
7.2 Surface treatment
Remove any superfluous material adhering to the unit as a result of the manufacturing process before
commencing the test.
8 Test procedure
8.1 Volume of voids
Place the air -dry unit on the thin sheet of foam rubbe r (6.1) or other resilient material with the open end of
voids uppermost.
When the unit has voids or recesses in the ends that need to be measured, close the ends with the rigid
plate (6.2).
8.2 Sand filling   procedure
Fill the glass measuring cylinder (6.3) accurately with the dry sand and record the volume. Fill the voids with
the sand by pouring from the cylinder, refilling it if required. Keep the cylinder lip as close as possible to the
top of the void, pour steadily and then strike off lev el.
Return to the cylinder any sand struck off and note the total volume of sand ( Vs,u) used to the nearest 104
mm3.
9 Calculation and expression of results
Calculate the gross volume of the unit ( Vg,u)   by multiplying the length ( lu) by the height  ( hu) and the width
(Wu) of the unit measured  in accordance  with DKS 2802:8 .
uuuu hWIVg , ……………………………………………………….eqn(1)
Calculate the net volume ( Vn,u)   of each unit to the nearest  104mm3, if required.'
u u uVsVgVn ,,, ……………………………………………. eqn(2)
Calculate the net volume ( Vn,u)   of each unit to the nearest 104mm3, if required.
%100,,uVguVseqn (3)
10 Evaluation of results
Calculate the mean value of the water absorption of the specimens to the nearest 0.1 %.CD/ENG/16 -5:2017
© KEBS 201 8—All rights reserved 311 Test report
a)The test report shall contain the following information:
b)thenumber, title and date of issue of this Kenya Standard;
c)the name of the organization that earned  out the sampling and the method used;
d)the date of testing;
e)the type, origin and designation  of the masonry unit by reference  to DKS 2801:1 ;
f)the number of specimens  in sample;
g)the net volume of each specimen  and the mean value to the nearest  104mm3;
h)the percentage  of voids of each specimen  and the mean  value, ifrequired, to the nearest  1%; and
i)remarks, if any.