Recycling of bituminous pavements with Portland cement : Portugal’s experiences and advances

Abstract

Recycling old bituminous pavements in situ with cement, is a solution for the structural reinforcement of degraded pavements whose acceptance and popularity are increasing in the whole world. It is emphasized the different aspects related with this kind of technique: previous definition, objectives, studies, work formula, stabilization, work period and cracking due to thermal retraction. A practical case of a real application is presented, in the rehabilitation of the road EN383 - Canhestros/Aljustrel - Portugal, where the aspects related to the construction are presented, as well as advantages and disadvantages of the application of the technique. On the other hand it is presented a study that allows the use of reclaimed asphalt material (RAP) in road bases or sub-bases, with improved behaviour, when compared with the traditional solutions, allowing the increase of the capacity of all pavement structure, making it possible to reduce the layers’ thickness, and the decrease of the use of natural resources. This technique can constitute a decision tool which can make possible the use of milled asphalt (RAP), in substitution of granular materials, in unbound layers. In this context a descriptive study of the pavements execution was put together using milled asphalt stabilized with stone dust and Portland cement, in substitution of well graded unbound granular materials, analyzing its behaviour and contribution for the overall resistance of the pavement structure.