Admixtures for caissons and façades of GRC

White façade GRC panels of UHPC

Santa Marta Airport on Columbia’s Caribbean coast is currently being expanded for use in the future as an international hub. For the façade of the new extension the client had specified precast concrete panels. These show plant motifs and were prod-uced by Tematik Barcelona, a specialist precast concrete manufacturer. Made from UHPC (Ultra High Performance Concrete), the GRC panels measure six by two metres and are five centimetres thick.
As they needed to be white fo rmaximum aesthetic effect, a white cement was selected for their formulation. However, this hardens faster than grey cement, which meant Tematik needed an admixture to ensure, among other things, a longer fabrication period. In tests, MC-PowerFlow 1120, a PCE-based superplasticiser, combined with a Centrament air-entraining agent produced the best results. The outcome was highly free-flowing concrete batches offering freedom from segregation over the entire consistency range combined with a low w/c ratio, high resistance values and excellent fair-faced quality.
A total of 106 façade panels are currently being installed over a total area of 812 square metres, adorning the airport building to produce an intricate, aesthetically elegant appearance.