Cost evaluation of foam bitumen and other stabilisation alternatives
As the demand for a cost efficient and environmental friendly pavement stabilisation method increases, so has foamed bitumen stabilisation for unbound granular pavement layers started to gain broad acceptance worldwide. The work forms part of a larger project aimed at investigating the feasibility and potential applications of the foamed bitumen stabilisation technique in order to speed up its adoption in New Zealand.
In this paper, a cost-analysis exercise comparing the capital cost of eight base course stabilisation alternatives in addition to hot mix asphalt (HMA) alternative was made. Cement, lime and foam bitumen stabilisation versus HMA design alternatives were compared. The foam stabilised mix represents a high quality base course material stabilised with 2.0% cement and 3.5% foam bitumen. The results of this analysis showed that foam bitumen stabilisation using high quality aggregates and about 2% cement is competitive compared to unbound materials because a reduced layer thickness is required.