A comparative study of roadblend and GB cement stabilizers

GB Cement additive is extensively used in the stabilisation of reconstruction projects throughout Queensland roads. Due to the nature/location of some projects the Department of Transport and Main Roads are currently investigating alternative binders which provide an extended working time. This project was undertaken on behalf of DTMR to research and compare GB Cement additive against a Sunstate Cement product ‘Roadblend’. The principal objective of this study is to provide the best data possible for determining the allowable working time of each binder from testing the effect of varying curing period at 0.75, 2, 3, 4, 6 and 24 hours on Maximum Dry Density (MDD). To maintain consistency in the results a UCS design was performed and only Nerimbra Quarry type 2.1 material (mixed thoroughly) was used for the project testing. The analysis of experimental results indicate that the amount of Roadblend additive required to obtain the desired unconfined compressive strength is nearly 50% less than the required amount of GB Cement. In the other hand, the allowable working time testing results were inconclusive and further testing is required to examine the possible extended working time of the Roadblend additive.