Design and characterization of coloured self-compacting concrete

LOPEZ, A.; TOBES, J.M.; GIACCIO, G.; POSITIERI, M.; OSHIRO, A.; ZERBINO, R.; BARRAGÁN, B.

Dubrovnik

Simposio; Concrete Structures – Stimulators of development, J. Radic ed., fib Symposium, 2007; 2007

fib Federation International du Beton

This work aims to study the effect of pigments in self-compacting concrete (SCC) characterizing the self-compacting parameters of coloured SCC (C-SCC). The test program corresponds to a joint research project between LEMIT (La Plata, Argentina) and ETSECCPB-UPC (Barcelona, Spain). Three pigments were employed in different dosages: iron oxides yellow and red, and black carbon. Firstly, evaluations of the mortar fluidity and passing ability for different pigment and superplasticizer dosages are presented. Based on these mortars, C-SCC were designed. In addition, colour was evaluated in hardened concrete. Measures of tristimulus values L*, a* and b*, represented in the chromatic space CIELab, were obtained on mortars and SCC. In a second part, the rheological parameters of C-SCC measured by using a BML viscometer, and the results of Slump-flow, J-Ring and V-Funnel tests are analyzed. From the results on coloured concrete with self-compacting characteristics it can be seen that the incorporation of pigment modifies not only the colour but also the properties in the fresh state. While Slump-flow remains almost constant Vfunnel times strongly increase in C-SCC compared with reference SCC, in this sense the incorporation of pigments affected the viscosity in a greater way than fluidity. The changes in workability depend on the type of pigment.