ICS 91.100.50; 93.080.20  
 
Reference number  
DRS 395-2: 2023 
© RSB 2023  
  
 RWANDA 
STANDARD  DRS  
395-2  
 
Second  edition  
223-mm-dd 
 
Bitumen and bituminous binders  — 
Part 2: Specification for paving grade  
bitumen  
   
DRS 395-2: 2023   
©RSB 2023 - 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 2023 
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
prior written permission from R SB. 
Requests for permission to reproduce this document should be addressed to : 
Rwanda Standards  Board  
P.O Box 7099 Kigali -Rwanda  
KK 15 Rd, 49  
Tel. +250 788303492  
Toll Free: 3250  
E-mail: info@rsb.gov.rw  
Website: www.rsb.gov.rw  
ePortal: www.portal.rsb.gov.rw   DRS 395-2: 2023  
iii                ©RSB 2023  - All rights reserved  
 Contents  Page 
1 Scope  ................................ ................................ ................................ ................................ .............  1 
2 Normative references  ................................ ................................ ................................ ...................  1 
3 Terms and definitions  ................................ ................................ ................................ ..................  2 
4 Requirements  ................................ ................................ ................................ ................................  2 
5 Sampling  ................................ ................................ ................................ ................................ ....... 6 
6 Evaluation of conformity  ................................ ................................ ................................ .............  6 
Annex  A (normative)  Calculation of the penetration index, Ip  ................................ ...........................  10 
Annex  B (normative)  Durability test method for bitumen  ................................ ................................ .. 12 
 DRS 395-2: 2023   
©RSB 2023 - All rights reserved                  iv 
 Foreword   
Rwanda Standard s are prepared  by Technical Committees and approved by Rwanda Standards Board (RSB) 
Board  of Directors in  accordance with the p rocedures of RSB, in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards.  
The main task of technical 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 gazettment as 
Rwanda Standards.  
DRS 395-2 was prepared by Technical Committee RSB/TC 55, Roads and highway engineering . 
In the preparation of this standard, referenc e was made to the following standard s: 
1) BS 12591: 2009 , Bitumen and Bituminous Binders  
2) ASTM D673 -16, Standard Specification for Performance Graded Asphalt Binder  
The assistance de rived from the above source is hereby acknowledged with thanks.  
This second edition cancels and replaces the first edition (RS  395-1: 2018 ), [clauses 1 and 4] which has been 
technically revised.  
DRS 395 consists of the following parts, under the general title Bitumen and bituminous binders : 
⎯ Part 1: Terminology  
⎯ Part 2: Speci fication for paving grade bitumen  
⎯ Part 3: Specification for bituminous emulsion (under development)  
Committee membership  
The following organizations were represented on the Technical Committee on Roads and highway engineering  
(RSB/TC 55) in the preparation of this standard.  
ASTRIK International Ltd  
EDITRACE LTD  and General Reliance  
JV CSC&EC(Property) and Fair Construction Ltd  
MININFRA  
NPD Ltd  DRS 395-2: 2023  
v                ©RSB 2023  - All rights reserved  
 Rwanda Inspectorate Competition and Consumer Protection Authority  (RICA)  
Rwanda Transport Development Agency (RTDA)  
TCMF Ltd  
University of Rwanda - College of Science Technology (UR -CST) 
Rwanda Standards Board (RSB) – Secretariat  DRS 395-2: 2023   
©RSB 2023 - All rights reserved                  vi 
 Introduction   
This Rwanda Standard describes performance required for a number of properties of bitumen and bituminous 
binders. Some of the properties are required by regulators and some are included only for the benefit of industry 
to assist specifying appropriate performance for different end uses.DRS 395-2: 2023  
1                ©RSB 2023  - All rights reserved  
 Bitumen  and bituminous binders — Part 2 : Specification for paving 
grade  bitumen  
1 Scope  
This Draft Rwanda  Standard provides a framework for specifying a range of properties and relevant sampling 
and test methods for bitumen, which is suitable  for use in the construction and maintenance of roads, airfields 
and other paved areas, together with requirements for evaluation of conformity.  
This Standard does not directly address ‘cohesion, adhesion and setting ability’.  
NOTE  Paving grade bitumen specified in this standard can also be used for industrial applications.  
2 Normative referen ces  
The following documents are referred to in the text in such a way that some or all of their content constitutes 
requirements of this document.  For dated references, only  the edition cited applies. For undated references, the 
latest edition of the refe renced document (including any amendments) applies.  
DRS 395 -1, Bitumen and bituminous binders ― Part 1: Terminology  
RS ISO 2592 , Petroleum and related products ― Determination of flash and fire points ― Cleveland open cup 
method  
RS ISO 4259 -1, Petroleum and related products ― Precision of measurement methods and results ― Part 1: 
Determination of precision data in relation to methods of test  
RS ASTM D7042 , Standard Test Method for Dynamic Viscosity and Density of Liquids by Stabinger Viscometer 
(and the Calculation of Kinematic Viscosity)  
RS ASTM D5 , Standard Test Method for Penetration of Bituminous Materials  
RS ASTM D140/D140M , Standard Practice for Sampling Asphalt Materials  
RS ASTM D36 , Standard Test Method for Softening Point of Bitumen (Rin g-and-Ball Apparatus ) 
RS ASTM D2042 , Standard Test Method for Solubility of Asphalt Materials in Trichloroethylene  
RS ASTM D2170/D2170M , Standard Test Method for Kinematic Viscosity of Asphalts (Bitumen)  
RS ISO 2719 , Determination of flash point ― Pensky -Martens closed cup method  
RS ASTM D1754 , Standard Test Method for Effects of Heat and Air on Asphaltic Materials (Thin -Film Oven 
Test)   
©RSB 2023 - All rights reserved                  2 
 RS ASTM D2872 , Standard Test Method for Effect of Heat and Air on a Moving Film of Asphalt (Rolling Thin -
Film Oven Test)  
RS ISO 3170 , Petroleum liquids ― Manual sampling  
RS ISO 9001 , Quality management system s ― Requirements  
3 Terms and definitions   
For the purposes    of this standard, the terms and definitions given in DRS 395 -1 apply.  
4 Requirements  
4.1 General  
This Standard covers a large range of bitumen to facilitate during design and the application of bituminous road  
pavement. The bitumen used for road construction can be classified into various classes, and bitumen covered 
by this standard will be from any of natural rock bitumen, native bitumen or petroleum bitumen.  
The variety of production techniques and applications makes it more practical to split bitumen  into two grade 
tables  (Clau se 4.2) that are based on two grading system. Two methods, viscosity  and penetration  are 
commonly used to classify  different grades  of bitumen.  
4.2 Properties  
4.2.1  General  
4.2.2.1  The properties of paving grade bitumen and related test methods shall be in accordance with Table 1A 
and Table1B, or Table 2A and Table 2B. When tested in  accordance with the methods given in the Tables, the 
various paving grades shall conform to the limits specified. Specific grade shall be selected from tables provided 
by choosing a column representing the specified values or ranges.  
Table 1A — Paving gra de bitumen specifications for grades from 30 x 0 .1 mm to 100 x 0 .1 mm 
penetration — Properties applying to all paving grade bitumen   
Property   Unit   30/45   40/50   50/70   60/70   80/100   Test method  
Penetration at 25 °C   0.1 mm   30 – 45   40 – 50   50 – 70   60 – 70   85–  
100  ASTM D5  
Softening point   °C   52 – 60   50 – 58   46 – 54   48 – 56   43 – 51   ASTM D36  
Resistance to hardening at 163 °C   -  -  -  -  -  -  ASTM D2872   
Retained penetration   %   ≥ 53   ≥ 53   ≥ 50   ≥ 50   ≥ 46   DRS 395-2: 2023  
3                ©RSB 2023  - All rights reserved  
 Increase in softening point, - 
Severity 1 or   
Increase in softening point, - Severity 
2 a  °C   
   
°C   ≤ 8  
or   
≤ 11   ≤ 8  
or   
≤ 11   ≤ 9  
or   
≤ 11   ≤ 9  
or   
≤ 11   ≤ 9  or  
≤ 11   
Change of mass b (absolute value)   %   ≤ 0.5   ≤ 0.5   ≤ 0.5   ≤ 0.5   ≤ 0.8   
Flash point   °C    ≥ 240   ≥ 240   ≥ 230   ≥ 230   ≥ 230   RS ISO 2592   
Solubility    %   ≥ 99.0   ≥ 99.0   ≥ 99.0   ≥ 99.0   ≥ 99.0   ASTM D2042   
a When Severity 2 is selected it shall be associated with the requirement for Fraass breaking point or penetration index or bot h 
measured on the un -aged binder (see Table 1B)   
b Change in mass can be either positive or negative.  
Table 1B — Paving grade bitumen specifications for grades from 30 x 0 .1 mm to 100 x 0 .1 mm 
penetration – Properties associated with regulatory or other international requirements  
Property   Unit   30/45   40/50   50/70   60/70   85/100   Test 
method  
Penetration index a   –   -1.5 to + 0.7  
or    
NR  c  - 1.5 to + 0.7 
or   NR  c  -1.5 to + 0.7 or  
NR  c  -1.5 to + 0.7 
or   NR  c  -1.5 to + 0.7  
or   NR  
c  Annex Ab  
Dynamic viscosity at 60 °C   Pa ⋅ s   ≥ 260  
 or    
NR  c  ≥ 225   
or   NR  
c  ≥ 175   
or   NR  
c  ≥ 145  
 or    
NR  c  ≥ 90  
 or    
NR  c  ASTM 
D7042   
Fraass  breaking point a   °C   ≤ - 5  
or   
NR  c  ≤ - 5  
or   
NR  c  ≤ - 7  
or   
NR  c  ≤ - 8  
or   
NR  c  ≤ - 10  
or   
NR  c  ASTM 
D36  
Kinematic viscosity at 135 °C   mm2/s   ≥ 400   
or   
NR  c  ≥ 370   
or   NR  
c  ≥ 325   
or   NR  
c  ≥ 295  ≥ 230  or   
 or    
NR  c   NR c   ASTM 
D2170    
©RSB 2023 - All rights reserved                  4 
 a When Severity 2 is selected it shall be associated with the requirement for Fraass breaking point or penetration index or bot h 
measured on the un -aged binder.   
b Reference to normative Annex A in this document dealing with the calculation of penetration i ndex.   
C NR. No Requirement may be used when there are no regulations or other regional requirements for the property in the territory  of 
intended use.   
  
Table 2A — Paving grade bitumen specifications – Soft bitumen: bitumen designated and specified by 
kinematic viscosity at 60 °C – Properties applying to all paving grade bitumen   
Property   Unit   V1500   V3000   V6000   V12000   Test method  
Kinematic viscosity at 60 °C   mm2/s    1000 – 2000   2000 – 4000   4000 – 8000   8000 – 16000   ASTM D2170  
Resistance to hardening at 
120 °C   -  -  -  -  -  ASTM D1754   
  
Change of mass a (absolute 
value)   %   
≤ 2.0   ≤ 1.7   ≤ 1.4   ≤ 1.0   
Flash point    °C   ≥ 160   ≥ 160   ≥ 180   ≥ 180   RS ISO 2719   
Solubility    %   ≥ 99.0   ≥ 99.0   ≥ 99.0   ≥ 99.0   ASTM D 2042   
a Change in mass can be either positive or negative.     
Table 2B — Paving grade bitumen specifications – Soft bitumen: bitumen designated and specified by 
kinematic viscosity at 60 °C - Properties associated with regulatory or other regional requirements   
  
Properties  Unit  V1500  V3000  V6000  V12000  Test method  
Resistance to hardening at 120 °C  TFOT   –  –  –  –  –  ASTM D1754  
  
Viscosity ratio at 60 °C   –  ≤ 3.0   
or  
NR a    ≤ 3.0  or   
NR  a   ≤ 2.5  
or  
NR a  ≤ 2.0  
or  
NR a  
a NR. No Requirement may be used when there are no regulations or other regional requirements for the property in the territory of intended  
use.  DRS 395-2: 2023  
5                ©RSB 2023  - All rights reserved  
 4.2.1.2  There is a subdivision of properties into two groups in the tables. The properties in Table 1A and  Table 
2A shall be specified for all paving grade bitumen. They are associated with regulatory requirements. The 
properties in Table 1B and Table 2B are requ ired to meet specific climatic conditions. They are associated with 
regulatory requirements.  
4.2.1.3  Two severity levels for resistance to hardening are stated as alternatives as, under specific conditions, 
a larger increase in softening point after Rolli ng Thin Film Oven Test (RTFOT) may be allowed (i.e. Severity 
level 2) without detrimental effect if this increase is associated with requirements for Fraass breaking point or 
penetration index (Ip) or both  
4.2.1.4  The properties in Table 1A shall be specif ied for all paving grade bitumen listed in this Table. They are 
associated with Health, safety and Environment requirements and shall be included in all specifications.  
4.2.1.5  The grades are designated by the nominal penetration or viscosity ranges as ap propriate.  
4.2.2  Consistency at intermediate service temperature  
Consistency at intermediate service temperature shall conform to the requirements for penetration value in 
Table 1A.  
4.2.3  Consistency at elevated service temperature  
Consistency at elevated service te mperature shall conform to the requirements for softening point in Table 1A 
(penetration graded), or kinematic viscosity in Table 2A (kinematic viscosity graded).  
4.2.4  Brittleness at low service temperature  
Brittleness at low service temperature may be requir ed to meet specific areas susceptible to extreme cold in 
some regions of Rwanda. Where required, paving grade bitumen shall conform to the requirements for Fraass 
breaking point in Table 1B.  
4.2.5  Temperature dependence of consistency  
Temperature dependence of consistency may be required to meet specific climatic conditions in the country. 
Where required, paving grade bitumen shall conform to the requirement for dynamic viscosity or penetration 
index (Ip) or both in Table 1B.  
4.2.6  Durability – Resistance to hardenin g  
4.2.6.1  Durability is demonstrated by compliance with the required surrogate characteristics of “Resistance to 
hardening”, defined in Table 1A, Table 2B.  
4.2.6.2  Resistance to hardening, rutting and fatigue shall be tested according to the Rolling Thin  Film Oven Test 
(RTFOT) in accordance with ASTM D 2872 for binders from Table 1A.  
4.2.6.3  Resistance to hardening, rutting and fatigue shall be tested according to the Thin Film Oven Test (TFOT) 
in accordance with ASTM D1754 for binders from Table 2A.   
©RSB 2023 - All rights reserved                  6 
 4.2.6.3. The durability is related to applied temperature during heating. During any application heating of 
bitumen  shall not be more than 160 oC to 170oC.  
4.2.7  Other properties  
4.2.7.1  Density  
When necessary, density of paving grade bitumen shall be determined in a ccordance with ASTM D70 -17 and 
ASTM D342 for cutback.  
4.2.7.2  Flash point  
Flash point shall be determined by the Cleveland open cup method in RS ISO 2592 for binders in Table 1A and 
by the Pensky -Martens closed cup method, RS ISO 2719, for binders in Table 2A.  
NOT E For bitumen in Table 1A, the Pensky -Martens closed cup method is often used to investigate possible contamination 
but is likely to give lower values than the Cleveland open cup method.  
4.3 Release of dangerous regulated substances  
Materials used in product s shall not release any dangerous substances in the environment.  
4.4 Precision  
In cases of uncertainty, the procedures described in RS ISO 4259 for interpretation of the results based on test 
method precision shall be used.  
5 Sampling  
5.1 Samples of bulk produc ts shall be taken as described in ASTM D140.  
5.2 Test samples shall be taken from the laboratory samples, and prepared for testing, as described in ASTM 
D140, RS ISO 4259 and RS ISO 3170.  
6 Evaluation of conformity  
6.1 General  
The compliance of paving grade bit umen with the requirements of this Standard and with the stated values 
(including grades) shall be demonstrated by:  
a) Initial Type Testing (ITT); and  
b) Factory Production Control (FPC).  
NOTE The information from evaluation of conformity is often available fo r audit as provided in a manufacturer's quality plan.  DRS 395-2: 2023  
7                ©RSB 2023  - All rights reserved  
 6.2 Type testing  
6.2.1  Initial Type Testing (ITT)  
Initial type tests shall be performed to show the conformity of the bitumen/bituminous binder with this Standard. 
Tests previously performed in accordance with the provisions of this Standard (same product, same 
characteristic(s), test method, sampling procedure, system of attestation of conformity, etc…) may be taken into 
account. All the characteristics required in the Standard shall be subject to initial type testing except dangerous 
substances, which may be declared by control of the raw materials, and characteristics where NR is chosen.  
6.2.2  Further Type Testing  
Whenever a change occurs in the base materials or the production process, which would change significantly 
one or more of the characteristics, the further type test shall be repeated for the appropriate characteristic(s).  
6.2.3  Sampling, testing and compliance criteria  
6.2.3.1  Sampling shall be taken as specified in Clause 5.  
6.2.3.2  The results of all type tests (initial and further type tests) shall be recorded, held by the manufacturer for 
at least five years from the date of the test and be available for inspection.  
6.2.4  Durability test for bitumen  
Durability of bitumen shall be teste d according to annex B.  
6.3 Factory Production Control (FPC)  
6.3.1  General  
6.3.1.1  The manufacturer shall establish, document and maintain an FPC system to ensure that the products 
placed on the market conform to the stated performance characteristics. The FPC sys tem shall consist of 
procedures, regular inspections, tests or assessments and the use of the results to control the quality of the 
finished product.  
6.3.1.2  An FPC system conforming to the requirements of RS ISO 9001 and made specific to the requirements  
of this standard shall be deemed to satisfy the above requirements.  
6.3.1.3  The results of inspections, tests or assessments requiring action shall be recorded, as shall any action 
taken. The action to be taken when control values or criteria are not met  shall be recorded and retained for the 
period specified in the manufacturer's FPC procedures.  
6.3.2  Equipment  
6.3.2.1  In accordance with testing, all weighing, measuring and testing equipment shall be calibrated and 
regularly inspected according to documented  procedures, frequencies and criteria.   
©RSB 2023 - All rights reserved                  8 
 6.3.2.2  In accordance with manufacturing, all equipment used in the manufacturing process shall be regularly 
inspected and maintained to ensure use, wear or failure does not cause inconsistency in the manufacturing 
process. Inspections and maintenance shall be carried out and recorded in accordance with the manufacturer's 
written procedures on equipment identified by the manufacturer as necessary to achieve or maintain product 
quality and the records retained for the period defined in the manufacturer's FPC procedures.  
6.3.3  Base materials  
The acceptance criteria for all incoming base materials shall be documented, as shall the inspection scheme 
for ensuring their conformity.  
6.3.4  Product testing and evaluation  
6.3.4.1  The ac ceptance criteria for all incoming base materials shall be documented, as shall the inspection  
scheme for ensuring their conformity.  
6.3.4.2  The manufacturer shall establish procedures to ensure that the stated values of all the characteristics 
are mainta ined. The characteristics and the means of control are:  
a) all characteristics shall be subject to the tests described in 6.2 and a minimum of once per year; and  
b) routine control of product quality shall be on a basis of checks, of a type and a frequency to b e defined and 
documented, to ensure that properties do not change significantly from those subject to type testing.  
6.3.4.3  The tests for consistency at intermediate and elevated service temperatures, and for durability, shall be 
carried out on a represen tative sample of product for supply to customers.  
Where batch production is carried out, the sample should be taken from the batch, which is considered as the 
quantity of bitumen produced and stored in one tank once the production run into tank has been co mpleted.  
The batch is considered to remain the same as long as no new production has been added.  
6.3.4.4  In case of loading through an in -line blender, the routine quality control may be carried out on the feeder 
tanks and a procedure for checking the pe rformance of the blender shall be in place.  
6.3.4.5  The appropriate testing frequencies vary with individual supply facilities, throughput and processes. 
Minimum frequencies shall be:  
a) consistency at intermediate service temperature: daily; if product is supplied directly from a tank that has 
not received new production then the minimum test frequency may be extended to a batch;  
b) consistency at elevated service temperatures: monthly; and  
c) durability, brittleness at low service temperature, temperature dependence of consistency: annually.  DRS 395-2: 2023  
9                ©RSB 2023  - All rights reserved  
 6.3.5  Traceability and mar king  
Individual product batches shall be identifiable and traceable with regard to their production origin. The 
manufacturer shall have written procedures ensuring that processes related to affixing traceability information 
and/or markings are inspected r egularly in compliance with RS ISO 9001.  
6.3.6  Non-conforming products  
The manufacturer shall have written procedures which specify how non -conforming products shall be dealt with. 
Any such events shall be recorded as they occur and these records shall be kept for the period defined in the 
manufacturer's written procedures in compliance with RS ISO 9001.  
6.3.7  Corrective action  
The manufacturer shall have documented procedures that instigate action to eliminate the cause of 
nonconformities in order to prevent recurre nce in compliance with RS ISO 9001.  
6.3.8  Handling, storage and packaging  
The manufacturer shall have procedures providing methods of product handling and shall provide storage areas 
that can prevent damage or deterioration.   
©RSB 2023 - All rights reserved                  10 
 Annex  A 
(normative)  
 
Calculation of the pen etration index, Ip  
A.1 General  
Penetration Index Ip is the indication of the thermal susceptibility of a bituminous binder. This Annex specifies 
the procedure to be used for calculating the penetration index, Ip, of paving grade bitumen when required by 
the d esigner, client or any other user.  
Example In relation to the specification for resistance to hardening given in Table 1A for grades between 35/40 
and 85/100.  
A.2 Principle  
The penetration index, Ip is calculated from the values of penetration at 25 °C, 100 g , 5 s, determined in 
accordance with ASTM D5 and the softening point, determined in accordance with ASTM D36.  
NOTE 1 It is based on the following hypothesis of Pfeiffer and Van Doormael:  
a) At the temperature of the softening point, the pene tration of a bitu men is 800 x 0. 1 mm.  
b) b) When the logarithm (base 10) of penetration is plotted against temperature, a straight line is obtained, 
the slope A of which is defined by:  
 
NOTE 2 A penetration index of zero is attributed to a bitumen with a penetration at 25 ° C of 200 × 0. 1 mm and 
a softening point of 40 °C.  
A.3 Determination  
Calculate the Ip from the following equation:  
 
Where:  
tRaB is the softening point, in degrees Celsius;  
DRS 395-2: 2023  
11                ©RSB 2023  - All rights reserved  
 lg P is the logarithm (base 10) of  the penetration at 25 °C (in 0. 1 mm)  
A.4 Expression of results  
Report the penetration index as the value, calculated according to A.3, rounded to the nearest 0,1 of a unit.  
A.5 Precision  
A.5.1  Repeatability  
The difference between two successive test results, obtained by the same operator with the same apparatus 
under constant operating conditions on identical test material would exceed 0.3 in only one case in twenty.  
A.5.2  Repeatability r  
The difference between two single and independent results obtained by different operat ors working in different 
laboratories on identical test material would exceed 0.5 in only one case in twenty.  
 
 
 
 
 
 
 
 
 
 
 
 
  
©RSB 2023 - All rights reserved                  12 
 Annex  B 
(normative)  
 
Durability test method for bitumen  
B.1 Principle  
Films of the test bitumen (1.0 mm thic k) are oxidised at 600C under 2. 069 kPa (300 psi) of air for 80 hours. The 
samples are removed after 80 hours and the dynamic shear modulus is measured at 5oC and 9 Hz and 
compared to standard values based on the behaviour of bitumen of the same penetration grade.  
This test method can be  used to assess the long -term field durability (resistance to oxidative hardening) of 
penetration grade bitumen.  
NOTE This test method involves the use of hazardous operations and equipment. It does not purport to address all of the 
safety problems associ ated with its use. It is the responsibility of the user of this method to establish appropriate safety and 
health practices and determine the applicability of regulatory limitations prior to use  
B.2 Test method  
B.2.1  Apparatus and Materials  
B.2.1.1 Cylinder of indus trial-grade compressed dry air, fittings and hose for connection to pressure vessel.  
B.2.1.2 Pressure vessel system is comprising of:  
a) pressure vessel certified for operation operation at 2069 kPa (300 psi) and 600C;  
b) thermocouple, thermistor or platin um resistance thermometer, and temperature logging device accurate to 
+0.10C, to measure the temperature inside the vessel;  
c) pressure release valve that prevents the pressure inside the vessel exceeding the maximum design pressure;  
d) pressure regulator capable of controlling the pressure inside the vessel at 2,069 +34 kPa (300+5 psi);  
e) pressure gauge readable to 10 psi and calibrated at 2069 kPa (300 psi); and  
f) slow release bleed valve to allow depressurization of the vessel from the test pressure to  atmospheric 
pressure over five to 10 minutes.  
B.2.1.3  Stainless steel or aluminium sample holders capable of holding at least 1.0 g of bitumen as a uniform, 
1.0 mm thick, horizontal film.  
B.2.1.4  A metal rack or holder capable of supporting at least thre e sample holders in a horizontal position so 
that the bitumen film thickness within the sample holders remains uniform.  DRS 395-2: 2023  
13                ©RSB 2023  - All rights reserved  
 B.2.1.5  A metal rack or holder capable of supporting at least three sample holders in a horizontal position so 
that the bitumen film thi ckness within the sample holders remains uniform.  
B.2.1.6  A stirred temperature -controlled fluid bath or forced - draft oven capable of maintaining the temperature 
inside the pressure vessel at 60.0 + 0.10C.  
a) if a water bath is used it must be fitted with a  water inlet and level control device so that a constant water 
level is automatically maintained over long periods; and  
b) b) both the bath or oven must be sufficiently large to allow air or the bath fluid to freely circulate around the 
vessel, and contain a  shelf or stand to allow the vessel to held in a horizontal (level) position.  
B.2.1.7  It is recommended is that the position of the vessel relative to the sides of the bath or oven is kept fixed  
B.2.1.8  A vacuum oven and pumping system capable of maintain ing 100 °C  ±  5°C and a vacuum of <6.9 kPa.  
B.2.1.9  Dynamic shear rheometer or similar instrument capable of applying sinusoidal loading and measuring 
the dynamic shear modulus of bitumen at 9 Hz and 5°C. 
B.2.1.10  Hotplate  
B.2.1.11  Balance readable and accurate to +0.001 g.  
B.3 Procedure  
B.3.1  Initial Setup of Pressure Vessel  
B.3.1.1  place the pressure vessel in the 60ºC water bath or oven to be used in the test, and pressurise to 2,069 
± kPa (300 ± 10 psi)  
B.3.1.2  the thermocouple should be  positioned near the vertical axis of the vessel and at approximately half 
height  
B.3.1.3  after four hours, log the temperature inside the vessel at 15 min intervals for at least 24 h and adjust if 
necessary so that a temperature of 60.0 °C ± 0.1 °C is main tained.  
B.3.2  Preparation of Sample Bitumen Films  
B.3.2.1  Weigh a sufficient quantity of bitumen onto the centre of the sample holder to achieve a 1.0  % ± 0.1  % 
mm film at 600 °C. If the density of the bitumen is not known assume a density of 1.0 g cm -3 at 60.0 °C 
B.3.2.2  Heat the sample holder on a hot plate at 90 °C -110°C for three to four minutes to achieve an even film, 
and allow to cool to room temperature on a level surface.   
©RSB 2023 - All rights reserved                  14 
 B.3.3  Ageing the bitumen films 
B.3.3.1  Before the test is begun, ensure that the pressur e vessel (containing the sample holder rack) is 
maintained at 60.0oC for at least four hours  
B.3.3.2  Remove the pressure vessel from the bath or oven and place the sample holders in the vessel  
B.3.3.3  Return the vessel to the bath and pressurize the vessel  to 2069 ± 34 kPa. The sample loading operation 
must be completed within five minutes and preferably as rapidly as possible to avoid cooling of the vessel  
B.3.3.4  After 15 -20 minutes, check the pressure in the vessel and re -adjust if necessary.  
B.3.4  Removing the bitumen films from the pressure vessel  
B.3.4.1  After 80 h (+15 min) allow the pressure vessel to depressurise slowly over about five minutes (to avoid 
excessive bubbling of the samples), and before removing the vessel from the bath  
B.3.4.2  Remove a sample holder and scrape the oxidised film into a sma ll vial. Heat the sample under vacuum 
(< 6.9kPa) at 100 °C ± 5°C for 30 min. Quickly release the vacuum, remove the vial and stir the sample. Store 
in a freezer.  
B.3.5  Modulus measurement  
Exact analysis details vary according to the type of rheometer used but a nalysis must be consistent from sample 
to sample.  
a)  The modulus measurement is carried out using an 8mm parallel geometry with a 1.0mm gap. Larger 
diameter plates can be used if it can be demonstrated that the compliance of the instrument is not 
significan tly affecting the measured modulus.  
b) A preliminary stress sweep may be necessary to ensure that the strain used lies within the linear viscoelastic 
region.  
c) The bitumen is annealed at 1200C for 10 minutes before testing; and  
d) The sample is brought to the te st temperature of 5.0±0.10C and the modulus measured at 9 ± 0.1Hz.  
B.3.6  Reporting  
The following information is to be reported:  
a)  ample identification and testing date;  
b) modulus (to the nearest MPa) of the untreated bitumen;and  
c) modulus (to the nearest MPa) of the oxidised bitumen (the Durability value)  DRS 395-2: 2023  
15                ©RSB 2023  - All rights reserved  
 B.3.7  Precision  
As a guide, based on measurements made on four different bitumen (ranging from 64 to 186 penetration at 
250C), the single operator repeatability of the measured modulus is +7%.  
  
©RSB 2023 - All rights reserved                  16 
 Bibliography  
[1] ASTM D979: 2015 , Standard Practice for Sampling Bituminous Paving Mixtures  
[2] ASTM D92 :2018 , Standard Test Method for Flash and Fire Points by Cleveland Open Cup Test  
[3] RS EAS 424: 2005 , Hydraulic road binders ―  Composition, specification s and conformity criteria  
[4] RS ASTM D3142 , Standard Test Method for Specific Gravity, API Gravity, or Density of Cutback 
Asphalts by Hydrometer Method  
 DRS 395-2: 2023 
 
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©RSB 2023 - All rights reserved