CEMENT STABILIZATION OF ROADS

CSIR Transportek

Frank Netterberg

Soillab

(C&CI Steering Committee)

Terms of Reference

• Consortium was contracted by the Cement and Concrete Institute (C&CI) on behalf of its members to:

– Investigate the influence of the new SABS EN 197-1 cement specifications on the use of cement as a road material stabilizer (ie is TRH 13 still appropriate).

Progress

• Interviews within the industry (completed) • Design laboratory test programme (completed)

• Carry out laboratory testing (commencing shortly)

(First material identified and being collected)(Cements being organised)

Laboratory test programme

• Initial programme was to:

• Test five suitable materials • Use 7 different cements• Study effect of:

– Time – Temperature on strength, workability – Cement composition and durability

• This would require about R8 million and about 196 tonnes of material

Revised programme

• Seven cements

• Two materials

• Initially workability and strength to be assessed

Cements

Cement Source Specific characteristics

CEM I 42,5 CEM I 42,5 CEM II B-V 32,5 CEM III A 32,5 CEM II A-L 32,5 CEM II A-M (S) 42,5 CEM II A-M (L) 42,5

PPC Hercules OPC Lafarge Lichtenburg Duratech Alpha All Purpose NPC Eagle Pro PPC Slurry Surebuild Alpha Roodepoort Lafarge Lichtenburg Powercrete

High C3A content Mod C3A content Fly ash Blastfurnace cement Limestone cement Slag Limestone

Full range of standard and non-standard cement tests on each cement

Materials

Dolerite (low plasticity index (PI < 6) Dolerite (medium-high PI (10 - 16)

Full range of standard and non-standard material tests on each sample

Stabilisation tests

•All tests at 3% cement and 100 % Mod AASHTO effortMaterials compacted after 2 and 4 hoursMaterials conditioned at 10, 23 and 45ºCCured for 7 days at 23°C and 95-100% humidity Tested for density and strength (CBR, UCS and ITS)

Proposed programme

• Initiate material testing –Mid November 2002

• Complete initial tests – End February 2003

• Report – End March 2003