Buoycrete, a light-weight concrete in combination with a membrane mold

In this study, the authors present Buoycrete, a new material and work method invented by the company Boskalis. “Buoycrete” is a new cement mixture and work method. This mixture and the work method related to this material are developed by Boskalis and are patented in 2017[1]. The material is a lightweight concrete mixture that is ‘neutrally buoyant’ and non-dissolvable. The concrete is intended to be used under water. The neutral buoyancy makes that the concrete does not sink or float. In other words, within the cement mixture under water, right after application, there is no resultant vertical force apparent because of the neutral buoyancy. The cement slurry will be kept in place only by the internal cohesion of the Buoycrete slurry itself. This allows for fast and flexible adjusting of the concrete shape under water before the concrete cures. The unique cement-based grout opens up a wide array of possible application areas and markets, especially since application equipment, mixing equipment and curing characteristics are analogue to normal cement mixtures. Currently, there are no comparable light-weight cement mixtures available on the market. This paper will start with an overview of concrete structures in combination with fabrics and will present the structural behavior, construction methods and applications of Buoycrete. It demonstrates that Buoycrete combined with fabric formwork creates new possibilities for the restauration of key walls but can also be used for the realization of façade elements, shell structures and other free forms.