Influence of inorganic pigments’ addition on the performance of coloured SCC

This paper presents the results of an investigation carried out to develop coloured self-compacting concretes (SCCs) especially devoted to architectural structures. Two different inorganic pigments were tested: the first is cobalt-salt based (for blue coloured SCC), the other iron-oxide based (for red coloured SCC). The leaching behaviour of the two inorganic pigments was assessed by means of leaching test, for estimating release of the most representative soluble ions concerning cementitious materials. The influence of the pigments’ addition on concrete rheology was previously studied by means of rheological tests carried out on cement pastes. Then, SCC mixtures were characterised at the fresh state by means of slump flow and V-funnel tests as well as after hardening by means of compression tests and free dying shrinkage measurements. Low water–cement ratio (equal to 0.45) was always adopted for durability reason. Moreover a shrinkage-free SCC was studied due to the combined use of a CaO-based expansive agent and Shrinkage Reducing Admixture.