Effect of self-cementing properties on the mechanical behaviour of recycled concrete aggregates in unbound pavement layers
Résumé
Recycled concrete aggregates (RCA) are increasingly being used in pavement
base and subbase layers to replace the natural unbound granular materials (UGM), while the
influence of their self-cementing properties on the mechanical behaviour has not been
thoroughly studied. In this paper, the self-cementing properties, permanent deformation and
resilient deformation behaviour of two RCA, NRCA and ORCA, showing significantly
different self-cementing properties, after curing for different times (1, 180, 360 and 720 days),
were investigated by pH value measurements, calorimeter tests and repeated load triaxial tests
(RLTT). The results show that the self-cementing properties can significantly improve the
mechanical behaviour of RCA, which is comparable to that of lightly treated materials. The
permanent deformations of NRCA, showing strong self-cementing properties, decreases to a
very low value quickly after curing for 180 days, and then stabilizes. While the resilient
modulus of NRCA increases continuously with curing time, up to the studied curing time (720
days), 4.3 times larger than that curing for 1 day. It was also found that the traffic loads can
damage the bonds between particles formed due to the self-cementing properties. On the
contrary, for ORCA, showing negligible self-cementing properties, curing has no influence on
the mechanical behaviour.
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Licence : CC BY NC ND - Paternité - Pas d'utilisation commerciale - Pas de modification
Licence : CC BY NC ND - Paternité - Pas d'utilisation commerciale - Pas de modification