Reference number  
DRS 373: 2017  
© RBS yyyy 
© RSB 2017   
 RWANDA 
STANDARD  DRS 
373 
 
1st  edition  
2017 -mm-dd 
 
Aggregate s for concret e — Specification  DRS 373: 2017  
©RSB 2017  All rights reserved                  ii 
 
 In order to match with technological development and to keep continuous progress in industries, 
Standards are subject to periodic review. Users shall ascertain  that they are in possession of the latest 
edition  
 
 
 
 
 
 
 
 
© RSB 2017  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized 
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E-mail: info@rsb.gov.rw   
Website: www.rsb.gov.rw   DRS 373: 2017  
iii                 ©RSB 2017  All rights reserved  
 
 Content  
1 Scope  ................................ ................................ ................................ ................................ ......................  5 
2 Normative references  ................................ ................................ ................................ ............................  5 
3 Terms and definitions  ................................ ................................ ................................ ...........................  6 
4 Geometrical requirements  ................................ ................................ ................................ ....................  7 
4.1 General  ................................ ................................ ................................ ................................ ...................  7 
4.2 Grading  ................................ ................................ ................................ ................................ ...................  7 
4.2.1  Coarse aggregate  ................................ ................................ ................................ ................................ .. 7 
4.2.2  Fine aggregate  ................................ ................................ ................................ ................................ ....... 8 
4.3 Shape of coarse aggregate  ................................ ................................ ................................ ..................  8 
4.4 Shell content  ................................ ................................ ................................ ................................ ..........  9 
4.5 Deleterious substances  ................................ ................................ ................................ ........................  9 
5 Physical requirements  ................................ ................................ ................................ ..........................  9 
5.1 General  ................................ ................................ ................................ ................................ ...................  9 
5.2 Particle density and water absorption  ................................ ................................ ................................  9 
5.3 Soundness  ................................ ................................ ................................ ................................ .............  9 
5.4 Drying shrinkage  ................................ ................................ ................................ ................................ ... 9 
5.5 Aggregate crushing value  ................................ ................................ ................................ ..................  10 
5.6 Ten percent fines value ................................ ................................ ................................ .......................  10 
5.7 Aggregate impact value  ................................ ................................ ................................ ......................  10 
5.8 Aggregate abrasion value  ................................ ................................ ................................ ..................  10 
6 Chemical requirements  ................................ ................................ ................................ .......................  10 
6.1 General  ................................ ................................ ................................ ................................ .................  10 
6.2 Chlorides  ................................ ................................ ................................ ................................ ..............  10 
7 Sampling and testing  ................................ ................................ ................................ ..........................  11 
7.1 Sampling  ................................ ................................ ................................ ................................ ..............  11 
7.2 Testing  ................................ ................................ ................................ ................................ ..................  11 
8 Supplier’s certificate  ................................ ................................ ................................ ...........................  11 DRS 373: 2017  
©RSB 2017  All rights reserved                  iv 
 
 Foreword  
Rwanda Standard s are prepared  by Technic al Committees and approved by R wanda Standards Board (RSB) 
Board  of Directors in  accordance with the procedures of RSB, in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards.  
The main task of technica l committees is to prepare national standards.  Final Draft Rwanda S tandards 
adopted by technical committ ees are ratified by me mbers of RSB Board of Director s for publication and 
gazetted  as Rwanda Standards.  
DRS 373  was prepared by Technical Committee RSB/TC 009, Building Materials and Civil Engineering . 
In the preparation of this standard, reference was made to the following standard s: 
1) ASTM C33/C33M – 13 ,Standard Specification for Concrete Aggregates  
2) BS EN 12620:2013 Aggregates for concrete  
The assistance  derived from the above source s is hereby acknowledged with thanks.  
Committee membership  
The following organizations were represented on the Technical Committee on RSB/TC 009, Building Materials 
and Civil Engineering  in the preparation of this standard.  
GiZ 
INES RUHENGERI  
Ruliba Clays  
Rwanda Housing Authority  
Standards for Sustainability  
University of Rwanda  
RSB(Secretariat)DRS 373: 2017  
5                 ©RSB 2017  All rights reserved  
 
 Aggregates for concrete — Specification  
1 Scope  
This standard specifies the properties of fine aggregate, coarse aggregate and filler aggregates obtained by 
processing natural, manufactured or recycled materials and mixtures of these aggregates for use in concrete. 
It covers aggregates having an oven dried particle density greater than  2 000 kg/m3 for all concrete, including 
for structu res cast in situ, precast structures, and structural precast products for buildings and civil engineering 
structures and concrete used in roads and other pavements and for use in precast concrete products.  
It also covers recycled aggregate with densities b etween 1 500 kg/m3 and 2 000 kg/m3.   
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 re ferenced 
document (including any amendments) applies.  
RS 96 -2, Methods of test for aggregates — Part 2: Guide to sampling and testing aggregate  
RS 96 -3, Methods of testing aggregates — Part 3: Method for sampling  
RS 96 -4, Methods of test for aggregates — Part 4: Methods for determination of particle size distribution — 
sieve tests  
RS 96 -5, Methods of test for aggregates — Part 5: Determination of particle shape – Flakiness index  
RS 96 -6, Methods of testing aggregates  — Part 6: D etermination of shell content  in co arse aggregate  
RS 96 -7, Methods of test for aggregates — Part 7: Determination of moisture content  
RS 96 -8, Methods of test for aggregates — Part 8: Determination of ten per cent fines value  
RS 96 -9, Methods of test for aggregates — Part 9: Determina tion of aggregate impact value (AIV)  
RS 96 -10, Methods of test for aggregates — Part 10: Determination of acid -soluble material in fine aggregates  
RS 96 -11, Methods of test for aggregates — Part 11: Methods for testing and c lassifying the drying shrinkage 
of aggregates in concrete  
ASTM C 127,  Standard Test Method for Relative Density (Specific Gravity) and Absorption of Coarse 
Aggregate   
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 ASTM C 88,  Standard Test Method for Soundness of Aggregates by Use of Sodium Sulfate or Magnesium 
Sulfate  
ASTM D 5821 , Standard Test Method for Resistance to Degradation of Small -Size Coarse Aggregate by 
Abrasion and Impact in the Los Angeles Machine  
ASTM C 131/C 131 M, Standard Test Method for Resistance to Degradation of Small -Size Coarse Aggregate 
by Abrasion and Impact in  the Los Angeles Machine  
RS EAS 18 -1, Cement  — Part 1: Composition, specification and conformity criteria for common cements  
3 Terms and definitions  
For the purposes of this standard, the follow ing terms and definitions apply .  
3.1 
aggregate  
granular materia l used in construction, such as sand, gravel, crushed stone, used with a cementing  medium to 
form hydraulic -cement concrete or mortar   
3.2 
natural aggregate  
aggregate resulting from the natural disintegration of rock and which has been deposited by streams  or glacial 
agencies  
3.3  
fine aggregate  
aggregate entirely passing  the 4.75 mm  sieve and predominantly retained on the 75 μm  sieve  
3.4  
course aggregate  
aggregate predominantly retained on the 4.75 mm sieve  
3.5 
all-in aggregate  
aggregate consisting of a mixture of coarse and fine aggregates  
3.6 manufactured aggregate  
aggregate of mineral origin resulting from an industrial process involving thermal or other modification  DRS 373: 2017  
7                 ©RSB 2017  All rights reserved  
 
 3.7  
recycled aggregate  
aggregate resulting from the processing of inorganic material previously used in construction  
3.8 
filler aggregate  
aggregate, most of which passes a 0 .063 mm sieve, which can be added to construction materials to provide 
certain  properties  
3.9 
grading  
particle size distribution expressed as the percentages by mass passing a specified set of sieves  
3.10 
fines 
particle size fraction of an aggregate which passes the 0 .063 mm sieve  
4 Geometrical requirements   
4.1 General  
The geometrical properties of aggregates shall be determined with consideration of the application conditions 
and origin of the aggregates, and in accordance with the test methods specified in this standard . 
Coarse aggregate shall consist of gravel, crushed gravel,crushed stone, or crushed hydraulic -cement 
concrete  or a combination thereof.  
Fine aggregate shall consist of natural sand, manufactured  sand, or a combination thereof.  
4.2 Grading  
The grading of the aggregate shall be determined by sieving  in accordance with RS 96 -4. 
4.2.1  Coarse aggregate  
The grading of coarse aggregates shall be within the appropriate limits given in Table 1. 
Table 1 — Grading of coarse aggregates  
Sieve  Percentage by mass passing test sieves (%)   
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 size 
(mm)  Nominal size of graded  
aggregates (mm)  Nominal size of single -sized aggregate (mm)  
40 to 5   20 to 5  14 to 5  40 20 14 10 5 
50 100 - - 100 - - - - 
37.5 90-100 100 - 85-100 100 - - - 
20 35-70 90-100 100 0-25 85-100 100 - - 
14 25-55 40-80 90-100 - 0-70 85-100 100 - 
10 10-40 30-60 50-85 0-5 0-25 0-50 85-100 100 
5 0-5 0-10 0-10 - 0-5 0-10 0-25 45-100 
2.36 - - - - - - 0-5 0-30 
Note For coarse recycled 20 mm and 10 mm single -sized aggregates, the percentage by mass passing 4 mm test sieve 
shall not exceed 5%.  
4.2.2  Fine aggregate  
The grading (i.e. Grading zone I,  Grading zone II , Grading zone III  as defined in table 2 below ) of fine 
aggregates shall be declared and documented by the  aggregate producer or supplier. This grading shall 
comply with both the overall limits and the limits for the declared grading given in Table 2. In addition, not 
more than one in ten c onsecutive samples shall have a grading outside the limits for the decl ared grading.  
Table 2 — Grading of fine aggregate  
Sieve size Percentage  by mass  passing for aggregate zones  
Overall limits  Limits for declared grading  
Grading zone I  Grading zone II  Grading zone III  
10mm  100 - - - 
4.75mm  90 to 100  - - - 
2.36mm  60 to  100 60 to 100  65-100 80-100 
1.18mm  30 to 100 30 to 90  45-100 70-100 
600µm  15 to 100 15 to 54 25-80 55-100 
300µm  5 to 70 5 to 40 5-48 2-70 
150µm  0 to 20 - - - 
4.3 Shape of coarse aggregate  
When required , the shape of coarse aggregates shall be determined in terms of the flakiness index . 
The flakiness index shall be the reference test for the determination of the shape of coarse aggregates  DRS 373: 2017  
9                 ©RSB 2017  All rights reserved  
 
 The flakiness index of coarse aggregates, determined in accordance with RS 96 -5, shall not exceed 15%.  
4.4 Shell content  
When required, the shell content of coarse aggregate, determined in accordance with RS 96 -6, shall not 
exceed 10%.  
4.5 Deleterious substances  
Aggregate shall not contain any harmful material, such as pyrites, coal, lignite, mica, shale or similar 
laminated mater ial, clay, alkali, soft fragments and organic impurities in such quantity as to affect the strength 
and durability of the concrete.  
The maximum quantity of deleterious substances shall not exceed 1.0 % by mass. For substances finer than 
75µm, the quantity  of deleterious substances shall not exceed 3.0 %  
 
5 Physical requirements  
5.1 General  
The necessity for testing all properties specified in this clause shall be limited according to the particular 
application at end use or origin of the aggregate. When required , the tests specified in this clause shall be 
carried out to determine appropriate physical properties.  
5.2 Particle density and w ater absorption  
When required the particle density and water absorption shall be determined in accordance with ASTM C 
127.Water ab sorption  shall not exceed 1.5%  
The minim um oven dried particle density of aggregates  shall be 2 000 kg/m3. 
5.3 Soundness  
The aggregate, when subjected to f ive cycles of the soundness determined in accordance with ASTM C 88 , 
shall not exceed the following limit s for weighted loss : 
a) For fine aggregates:  10 % when tested with sodium sulphate ( Na 2SO 4 )and 15 %when tested with 
magnesium sulphate  (MgSO 4). 
b) For coarse aggregates:  12 % when sodium sul phate (Na 2SO 4) is used or 18 %t when magnesium 
sulphate (MgSO 4) is use d.  
5.4 Drying shrinkage  
The drying shrinkage of aggregates used in structural concrete, when determined in accordance with RS 96 -
11, shall not exceed 0.075%.   
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 5.5 Aggregate  crushing value  
The aggregate crushing value , determined in accordance with ASTM D 5821,  shall not exceed 30 percent.  
NOTE 1 The aggregate crushing value  gives a relative measure of the resista nce of coarse  aggregate to crushing under a 
gradually applied c ompressive load.  
NOTE 2   The aggregate crush ing value test is made on aggregate passing a 12.5mm s ieve and retained on a 10 mm 
sieve.  
5.6 Ten percent fines value  
The ten percent fines value shall be determined in accordance with RS 96 -8. 
5.7 Aggregate impact value  
The aggregate impact value  for coarse aggregate , when determined in accordance with RS 9 6-9, shall not 
exceed 30 percent.  
NOTE   The aggregate impact value gives a relative measure of the resistance of an aggregate to sudden shock or 
impact, which in some aggregates differs from its resistance to a slow compressive load.  
5.8 Aggregate abrasion val ue 
The aggregate abrasion value  for coarse aggregate , when determined  in accordance with ASTM C 131 using 
Los Angeles machine, shall not exceed 30 percent . 
6 Chemical requirements  
6.1 General  
The chemical properties of aggregates shall be determined with conside ration of the application conditions 
and origin of the aggregates, and in accordance with the test methods specified in this Standard.  
6.2 Chlorides  
The acid -soluble chloride ion content of aggregates for concrete shall be determined in accordance with  RS 
96-10. 
The chloride ion contents of the combined natural aggregates shall not exceed the limits given in Table 3 for 
three  categories of concrete.  DRS 373: 2017  
11                 ©RSB 2017  All rights reserved  
 
 Table 3 — Limits for chloride ion content of natural aggregates  
Type and use of concrete  Chloride ion content exp ressed as percentage by mass of 
combined natural aggregates (%)  
Prestressed concrete and heat -cured concrete containing 
embedded metal  0.01 
Concrete containing embedded metal and made with 
cement complying with RS  EAS 18 -1 0.05 
Other concrete  No limit  
The chloride ion content of the natural aggregates and coarse recycled aggregate when combined in use shall 
not exceed 0.05% by mass.  
The acid -soluble sulphate content of natural aggregates shall not exceed 0.8% by mass.  
The acid -soluble sulphate content o f coarse recycled aggregate shall not exceed 1% by mass.  
The total sulphur content of natural aggregates shall not exceed 1% by mass.  
When required the water -soluble chloride ion content of aggregates for concrete shall be determined in 
accordance with  ASTM C 1524.  
NOTE  If the water -soluble chloride ion content of the combined aggregate is known to be 0.01 % or lower (e.g. for 
aggregates extracted from most inland quarries) this value can be used in the calculation of the chloride content of 
concrete . 
7 Sampl ing and testing  
7.1 Sampling  
The guidance to sampling and method of sampling shal l be in acc ordance with RS 96 -2 and RS 96 -3 
respectively . 
7.2 Testing  
The amount of material required for each test shall be as specified in the relevant method of  test given in RS 
96-4 to RS 96 -11 in addition to ASTM test methods quoted in this standard . 
8 Supplier’s certificate  
The supplier shall satisfy him /herself that the material complies with the requirements of this standard and, if 
requested, shall supply a certificate to this effect to the purchaser.   
©RSB 2017  All rights reserved                  12 
 
  If the purchaser requires independent tests to be made, the sample for such tests shall be taken before or 
immediately after delivery according to the option of the purchaser, and the tests carried out in accordance 
with this stan dard and on the written instructions of the purchaser.  
The supplier shall supply free of charge the material required for tests.  
 
 
 
 
 DRS 373: 2017  
13                 ©RSB 2017  All rights reserved  
 
 Bibliography  
[1]  CS 3:2013 Construction Standard, Aggregates for Concrete  
[2] SANS 1083 , Aggregates from natural sources — Aggre gates for concrete  
 
 
  
  DRS 373: 2017  
ICS 91.100.15  
 
©RSB 2017  All right s reserved