Influence of fine recycled concrete aggregates on the properties of mortars
Elsevier, 2015
Online
academicJournal
Zugriff:
Fine recycled concrete aggregates (FRCA) also called recycled sand, having particle sizes smaller than5 mm, are essentially composed of mortar and hardened cement paste. Therefore they induce a largewater demand which makes them hard to recycle into mortar and concrete. In this paper, the propertiesof mortars containing FRCA have been studied, including fresh properties, mechanical properties andinterfacial transition zone (ITZ) microstructure.The influence of saturation state of FRCA (dried or saturated) on the properties of mortars of identicalcompositions has first been studied. The results showed that the slump of mortars containing dried FRCAis always larger than that of mortars containing saturated FRCA. Indeed, in the case of dried FRCA, thetheoretical amount of absorbed water is added at the beginning of mixing leading to a temporary increaseof the initial efficient W/C ratio and volume of paste, leading to a better workability before its absorptioninto FRCA. On the contrary, the absorbed water in saturated FRCA is not readily available and thus cannotcontribute to increase the initial efficient W/C ratio. Moreover, the compressive strength of mortars containingdried FRCA is always larger than that of mortars made with saturated FRCA, which is attributed toa thinner interfacial transition zone improving its mechanical properties. The influence of the fraction ofrecycled sand and of the granular class of recycled sand on the mechanical properties of mortars has thenbeen studied with saturated FRCA. The compressive strength of mortars decreases quasi linearly as thereplacement percentage of recycled sand increases. Moreover, it is shown that the finer fraction of recycledsand (0/0.63 mm) has the worse effect on the mechanical properties of mortars.
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Influence of fine recycled concrete aggregates on the properties of mortars
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Autor/in / Beteiligte Person: | Zhao, Zengfeng ; Remond, Sébastien ; Damidot, Denis ; Xu, Weiya |
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Veröffentlichung: | Elsevier, 2015 |
Medientyp: | academicJournal |
DOI: | 10.1016/j.conbuildmat.2015.02.037 |
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