1. CEMENTITIOUS STABILISATION OF ROAD CONSTRUCTION MATERIALS: QUO VADIS Phil Paige-Green, CSIR-Transportek, Pretoria Frank Netterberg Consultant

2. INTRODUCTION l Stabilisation of marginal materials is still an important part of road building in RSA l Will probably become more important as good materials are depleted l Specification of stabilisation is based on: –COLTO Standard Specs for R&B (1996) –with assistance from Draft TRH 13 (1986)

3. INTRODUCTION l Cement stabilisation experience incorporated in COLTO and TRH13 was based mainly on the use of: –Ordinary Portland Cement (SABS 471) –PBFC (SABS 626) –Portland cement blends (SABS 831) –Portland flyash cement (SABS 1466) l Things have changed !!

4. SABS ENV 197-1 l In 1992, became a European pre-standard (ENV) l After 3 years should be upgraded to European standard (EN) ?? l Adopted “as is” by SABS in 1996 for RSA l Applicable to “common cements” l Similar spec for masonry cements (SABS ENV 413-1) l Concentrate on SABS ENV 197-1 as this is most relevant for roads

5. NEW REQUIREMENTS l Totally different classification system l 5 cement types –9 groups (depend on additive) l 19 subgroups (depend on composition) l Also classified by strength and rate of strength gain (6 additional permutations)

6. CLASSIFICATION l IPortland cement l IIOther Portland cements l Portland slag cement l Portland silica fume cement l Portland flyash cement l Portland limestone cement l Portland composite cement l IIIBlastfurnace cement l IVPozzolanic cement l VComposite cement

8. Strength requirements Strength class Compressive strength (MPa) Early strengthStandard strength 2 days7 days28 days 32.5-≥ 16.0≥ 32.5≤ 52.5 32.5R≥ 10.0- 42.5≥ 10.0-≥ 42.5≤ 62.5 42,5R≥ 20.0- 52.5≥ 20.0-≥ 52.5- 52.5R≥ 30.0-

9. STANDARD DESIGNATION l Cement ENV 197-1 CEM I 32.5 –(equiv to OPC ?) l Cement ENV 197-1 CEM II/A-S 42.5

10. CHEMICAL PROPERTIES SABS 471SABS ENV 197-1 Lime sat factor 0.66 -1.02CaO/SiO 2 ≥ 2 MgO cement ≤ 5%MgO clinker ≤ 5% Max SO 3 = 3.0 – 3.5 %Max SO 3 = 3.5 – 4.0 % (4.5) Max LoI = 4 %Max LoI = 5 % Max insoluble residue = 2.5%Max insoluble residue = 5% Chloride N/SMax chloride 0.1% Pozzolanicity N/SPozzolanicity - Yes

11. PHYSICAL PROPERTIES PropertySABS 471ENV 197-1 Max % >212 μm1.2 0.5 (RH) N/S Min specific surface area (cm 2 /g) 2250 3250 (RH) N/S Min UCS (MPa) 3 days 7 days 16 21 (RH) 24 28 (RH) Earlier table Min transverse str (MPa) 3 days 7 days 1.8 2.8 (RH) 2.8 3.8 (RH) N/S

12. PHYSICAL PROPERTIES (cont) PropertySABS 471ENV 197-1 Setting times: Min initial (min) Max final (hrs) 45 45 (RH) 10 10 (RH) 45 – 60 N/S Soundness: Max expansion (mm) 10 10 (RH)10

13. STRENGTH

15. Strength requirements Strength class Compressive strength (MPa) Early strengthStandard strength 2 days7 days28 days 32.5-≥ 16.0≥ 32.5≤ 52.5 32.5R≥ 10.0- 42.5≥ 10.0-≥ 42.5≤ 62.5 42,5R≥ 20.0- 52.5≥ 20.0-≥ 52.5- 52.5R≥ 30.0-

16. CHEMICAL PROPERTIES SABS 471SABS ENV 197-1 Lime sat factor 0.66 -1.02CaO/SiO 2 ≥ 2 MgO cement ≤ 5%MgO clinker ≤ 5% Max SO 3 = 3.0 – 3.5 %Max SO 3 = 3.5 – 4.0 % (4.5) Max LoI = 4 %Max LoI = 5 % Max insoluble residue = 2.5%Max insoluble residue = 5% Chloride N/SMax chloride 0.1% Pozzolanicity N/SPozzolanicity - Yes

17. PHYSICAL PROPERTIES PropertySABS 471ENV 197-1 Max % >212 μm1.2 0.5 (RH) N/S Min specific surface area (cm 2 /g) 2250 3250 (RH) N/S Min UCS (MPa) 3 days 7 days 16 21 (RH) 24 28 (RH) Earlier table Min transverse str (MPa) 3 days 7 days 1.8 2.8 (RH) 2.8 3.8 (RH) N/S

18. PHYSICAL PROPERTIES (cont) PropertySABS 471ENV 197-1 Setting times: Min initial (min) Max final (hrs) 45 45 (RH) 10 10 (RH) 45 – 60 N/S Soundness: Max expansion (mm) 10 10 (RH)10

19. STRENGTH