Reappraisal of Recycled Concrete Aggregate as Coarse Aggregate in Concretes for Rigid Pavements

Abstract

State departments of transportation began using recycled concrete aggregate (RCA) as aggregate in portland cement concrete pavement in the United States in the late 1970s. Although RCA is rarely used in current U.S. rigid pavement slabs, the impetus for its continued use remains the same: a lack of landfill space, a shortage of nearby quality natural aggregates, or both. However, as American pavement engineers and researchers place a greater emphasis on sustainable, reusable roadways, the status quo for RCA in American roadways should be reconsidered along with these new priorities. This study proposes to revisit the use of recycled concrete as aggregate in rigid pavement slabs by using overlooked research to address the concerns that prevented the wide-scale adoption of recycled concrete as an aggregate in pavement slabs by state departments of transportation. Experiences encountered in countries (mostly restricted to Europe) where the use of RCA in rigid pavement is more common are also described. New opportunities for the use of RCA as a structural component in pavement concretes are detailed.

On Probability Distribution of Chloride Diffusion Coefficient for Recycled Aggregate Concrete

“…It is necessary to well understand the properties of RCA in order to control the behaviour of RAC. Some hypothetical problems related to durability aspects have resulted in RCA being employed only as base filler for pavement construction (Muscalu et al 2013;Vancura et al 2009), thereby and unnecessarily limiting the scope of application of RCA. The durability of concrete is of great concern, especially in high-chloride environments such as coastal areas and where de-icing salt is used in cold regions, and so determining the chloride diffusion characteristics of concrete is required in order to control the durability of concrete structures (Morga and Marano 2015).…”

Two-lift concrete paving for sustainable pavements

“…Table 1 presents the European and U.S. experiences with two-lift concrete pavements. (Berry et al, 2013;Tompkins et al, 2009;Cable et al, 2004;Vancura et al, 2009;Tompkins et al, 2010;Akkari and Izevbekhai, 2011;Debroux and Dumont, 2005;Rens et al, 2008;Bilec et al, 2010;Smiley, 2010;Wojakowski, 1998…”

Durability of Recycled Aggregate Concrete: An Overview

“…Some basic conclusions confirmed are for example: the compressive strength of concrete prepared with natural coarse aggregates (NCA) is higher than that of RAC and the interrelationships between the mechanical properties of RAC could be quite different from those of NAC. However, some hypothetical problems related to durability resulted in recycled aggregates being employed practically only as base filler for pavement construction (Etxeberria et al 2007;Park et al 2005;Vancura et al 2009;Tam et al 2006;Richardson and Jordan 1994). Engineers generally concern about the durability of RAC.…”