Cold in place recycling, as an alternative to milling and standard replacement, shows a series of technical, economic and environmental advantages, which have done its use to grow in Spain, especially from 1990 onwards. Nevertheless, these actions have revealed certain aspects and limitations that prevent cold recycling from being considered a fully consolidated technique nowadays.The use of vaguely defined criteria for the design of the recycled mix, the lack of criteria for construction control as well as of specifications about the end product, and the ignorance of the evolution of the material performance with time have given cold recycling some technical insecurity.In this article, the problems arising from the standard methodology used for the design of cold recycled mixes have been analysed firstly, as well as the effect that certain variables, compaction and curing especially, have on their properties. Secondly, the effect that the use of both emulsion and cement during recycling has on the mix properties has been studied,
Fatigue cracking of bituminous mixtures is closely related to the loss of ductility produced by the stiffening of the bituminous binder. The main two factors that cause the asphalt binder to lose its ductility are aging and exposure to low temperatures. However, most of the tests designed to evaluate the fatigue behavior of bituminous mixtures are very time consuming, and make unpractical those studies that try to evaluate the influence of many variables. In this research project a strain sweep test was used to analyze the influence of aging, test temperature and bituminous binder type on the fatigue behavior of a continuously graded mixture. As expected, the mixture with SBS polymer modified binder retained more ductility at low temperatures, while the mixture with crumb rubber modified binder had the highest stiffness modulus. All mixtures exhibited the worst fatigue behavior at low temperatures and aging was equivalent to testing an unaged mixture at a lower temperature. The main result of this paper was the implementation of a new methodology to estimate the fatigue law of the material using a strain sweep test, which allowed this fatigue analysis to be carried out in nearly 10 times less testing time than that required by the procedure described in the EN 12697-24 standard.Peer ReviewedPostprint (author's final draft
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.