Flowability and Stability Performance of Self-Consolidating Concrete in Full-Scale Beam

International audienceFlowability and stability performance of various self-consolidating concrete (SCC) mixtures in a full-scale reinforced concrete beams were evaluated. The mixtures were cast under gravity using a V-funnel measuring 1.7 in height. The beam is 4 m in length and 0.20 x 0.20 m2 in cross section. The beam is reinforced with 10-mm diameter longitudinal bars and 10-mm stirrups placed at 150-mm distancel. The effect of mix design and the stability of the SCC on the flowability and passing ability of the concrete cast in the vertical and horizontal directions along the beams is evaluated. The investigated mixtures were made with different water-to-cementitious materials ratio (w/cm) and high-range water-reducing agent (HRWRA) dosage rates. The investigated SCC mixtures had a slump flow of 700 ± 10 mm and V-funnel flow times ranging between 1.75 and 6.75 s. The flowability performance was evaluated in terms of flow velocity of concrete determined at different locations along the beam. The dynamic stability was assessed at the top and bottom zones of different sections along the reinforced beam. Static stability was assessed using a rectangular column measuring 1.5 m in height and 200 x 200 mm in cross section. The variations in ionic concentrations were exploited to derive stability indexes with regards to bleeding and homogeneity of concrete. Derived stability indexes included bleeding coefficient, segregation coefficient, and homogeneity index. Test results showed that the increase in coarse aggregate content could improve the flow performance of SCC. On the other hand, SCC made with relatively higher paste volume of 40% is shown to exhibit lack of static and dynamic stability. The rheology of suspending phase should be then adjusted given the casting conditions and the mixture design