Construction and demolition waste (CDW) recycling is generally limited to the use of the coarser fraction as aggregate for new concrete. The recovery of fine aggregates requires a cleaning by removing the hydrated cement waste (HCW). In this paper, the possibility to use HCW extracted from CDW as alternative component for the production of new clinker is explored. A pure HCW sample was prepared and used in partial replacement of natural materials in raw admixtures for new clinker production. At a replacement degree of 30%, a new Portland clinker containing almost 50% of C3S could be produced with a huge spare in the release of CO2 (about 1/3 less). At higher HCW dosage a non-Portland clinker containing almost 80% of C2S has been obtained: its use as supplementary cementing material in blended cements revealed satisfying long term performances.
An investigation on the recycling of hydrated cement from concrete demolition waste
Gastaldi D.
;Buzzi L.;Boccaleri E.
;
2015-01-01
Abstract
Construction and demolition waste (CDW) recycling is generally limited to the use of the coarser fraction as aggregate for new concrete. The recovery of fine aggregates requires a cleaning by removing the hydrated cement waste (HCW). In this paper, the possibility to use HCW extracted from CDW as alternative component for the production of new clinker is explored. A pure HCW sample was prepared and used in partial replacement of natural materials in raw admixtures for new clinker production. At a replacement degree of 30%, a new Portland clinker containing almost 50% of C3S could be produced with a huge spare in the release of CO2 (about 1/3 less). At higher HCW dosage a non-Portland clinker containing almost 80% of C2S has been obtained: its use as supplementary cementing material in blended cements revealed satisfying long term performances.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
