1. New Cement Specification and Cement Types Road Pavements Forum Thursday 17 May 2001

2. Historical product range in South Africa l OPC - SABS 471 l RHC - SABS 471 l PBFC - SABS 636 l PC15 (SL or FA) - SABS 831 l PFAC - SABS 1466 l Masonry cements - no standard

3. Cement extenders l SABS 1491 covers the quality of extenders for use at the mixer l Slags from Iscor at Pretoria, Newcastle and Vanderbijlpark were confirmed suitable through research l Fly ashes from Matla and Lethabo were also shown to meet requirements in extensive test programmes

4. SABS adopts new cement standards in 1996 l SABS ENV 197-1 covering “Common Cements” l SABS ENV 413-1 covering “Masonry Cements”

6. Nomenclature l CEM I, II, III, IV and V l I - Portland cement l II - Portland ……… cement l III - Blastfurnace cement l IV - Pozzolanic cement l V - Composite cement l A, B or C l indicates level of extender e.g. in CEM II A is 6-20% and B is 21-35%

7. Nomenclature (cont.) l Extender type l S - Blastfurnace slag l D - Silica fume l V or W - Fly ash l L - Limestone l M - Composite

8. Nomenclature (cont.) l Strength grade

9. Nomenclature (cont.) l Example CEM II B-W 42,5 l Portland fly ash cement l Containing 21 to 35% fly ash l 2-day-strength > 10 MPa l 28-day-strength > 42,5 and < 62,5 MPa

10. Average 28-day compressive strength of OPC/CEM I 42,5

13. Factors to be considered when selecting cement type l Cost of concrete l 28-day compressive strength l Early compressive strength development l Ability to resist aggressive environment l Sensitivity to poor site practices and extent of supervision l Other properties (colour, heat development, control of ASR, etc.)

14. Cautionary remarks l Do not extrapolate performance data for one cement as representing all cements l Do not assume that what is permitted in Europe will automatically work in SA l Ask for details of product performance from the manufacturer - check uniformity and performance relative to the issues of importance l Do not think that a SABS mark indicates that the cement is fit for any application

15. Thank you all for your attendance