New Cement Specification New Cement Specification and Cement Typesand Cement Types
Road Pavements Forum Road Pavements Forum
Thursday 17 May 2001Thursday 17 May 2001
Historical product range in Historical product range in South AfricaSouth Africa
OPC - SABS 471 RHC - SABS 471 PBFC - SABS 636 PC15 (SL or FA) - SABS 831 PFAC - SABS 1466
Masonry cements - no standard
Cement extendersCement extenders SABS 1491 covers the quality of extenders
for use at the mixer
Slags from Iscor at Pretoria, Newcastle and Vanderbijlpark were confirmed suitable through research
Fly ashes from Matla and Lethabo were also shown to meet requirements in extensive test programmes
SABS adopts new cement SABS adopts new cement standards in 1996standards in 1996
SABS ENV 197-1 covering “Common Cements”
SABS ENV 413-1 covering “Masonry Cements”
NomenclatureNomenclature
CEM I, II, III, IV and V I - Portland cement II - Portland ……… cement III - Blastfurnace cement IV - Pozzolanic cement V - Composite cement
A, B or C indicates level of extender e.g. in CEM II A is 6-20% and B is 21-35%
Nomenclature (cont.)Nomenclature (cont.)
Extender type S - Blastfurnace slag D - Silica fume V or W - Fly ash L - Limestone M - Composite
Nomenclature (cont.)Nomenclature (cont.)
Strength grade
Compressive strength, MPaEarly strength Standard
strengthStrengthClass
2 days 7 days 28 days32,5N - 16,032,5R 10,0 -
32,5 52,5
42,5N 10,0 -42,5R 20,0 -
42,5 62,5
52,5N 20,0 -52,5R 30,0 -
52,5 -
Nomenclature (cont.)Nomenclature (cont.)
Example CEM II B-W 42,5 Portland fly ash cement Containing 21 to 35% fly ash 2-day-strength > 10 MPa 28-day-strength > 42,5 and < 62,5 MPa
Average 28-day compressive Average 28-day compressive strength of OPC/CEM I 42,5strength of OPC/CEM I 42,5
0
10
20
30
40
50
60
94/43 95/15 95/39 96/11 96/35 97/07 97/31 98/03 98/27 98/51 99/22 99/46 00/18 00/42
Date
28
-d IS
O (
MP
a)
CEMENTTYPE
CEM I CEM IIA-M
CEM IIA-S
CEM IIB-S or
W
CEM II A-L
CEM II A-V or W
CEM II B-V CEM III A CEM V A
CEMENTGRADE
52,5 42,5R
42,5 32,5
Alpha RapidHard
- PortlandCement
- - - All PurposeCement
All PurposeCement
BuildingCement
- -
AlphaSwaziland
- - - - - - - - Multi PurposeCement
- -
Lafarge Duracast - Duratech Powercrete - - - - Buildcrete 32,5 - -NPC - Eagle
Super- - Eagle
Plus/Premium
EaglePlus
- - - Eagle Pro -
PPC Rapo Rapo OPC - - - Surebuild Surebuild Surecrete - -PPCBotswana
- - - - - - - - Botcem - -
Slagment - - - - - - - - - Geotech 50 -
Factors to be considered Factors to be considered when selecting cement typewhen selecting cement type
Cost of concrete 28-day compressive strength Early compressive strength development Ability to resist aggressive environment Sensitivity to poor site practices and extent of
supervision Other properties (colour, heat development,
control of ASR, etc.)
Cautionary remarksCautionary remarks Do not extrapolate performance data for one
cement as representing all cements Do not assume that what is permitted in Europe
will automatically work in SA Ask for details of product performance from the
manufacturer - check uniformity and performance relative to the issues of importance
Do not think that a SABS mark indicates that the cement is fit for any application
Thank you all for your Thank you all for your attendance attendance
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