The effect of chloride and sulfate on Completely Recyclable Concrete

Completely Recyclable Concrete (CRC) is intended to be recycled as raw material within the cement production from a predesign stage. However, concrete contributions that are exposed to aggressive environments (e.g. industrial and seaside buildings), could carry elements such as chlorides, sulfur and alkalis after demolition, which will end up in the recycled material. The aim of this study is to better understand the influence of chloride and sulfur in CRC on the final clinker properties. The laboratory testing was conducted by using calcium chloride and calcium sulfate as a source of chloride and sulfur respectively. All raw mix samples were burnt in an electrical furnace at 1450°C. The produced clinkers were characterized by X-Ray Diffraction (XRD) for the identification of the mineralogical phases formed during sintering.Completely Recyclable Concrete (CRC) is intended to be recycled as raw material within the cement production from a predesign stage. However, concrete contributions that are exposed to aggressive environments (e.g. industrial and seaside buildings), could carry elements such as chlorides, sulfur and alkalis after demolition, which will end up in the recycled material. The aim of this study is to better understand the influence of chloride and sulfur in CRC on the final clinker properties. The laboratory testing was conducted by using calcium chloride and calcium sulfate as a source of chloride and sulfur respectively. All raw mix samples were burnt in an electrical furnace at 1450°C. The produced clinkers were characterized by X-Ray Diffraction (XRD) for the identification of the mineralogical phases formed during sintering.C