Cemex has launched a rapid hardening, controlled set concrete
Called Promptis, it enables formwork to be stripped much earlier than traditional products. The company says the concrete has a strength of 4MPa after four hours but also retains initial flow properties of up to 90 minutes. Cemex says that Promptis can also be used for precast applications, where structures can be de-moulded ready for storage after 12 hours. The concrete includes superplasticisers, polymers and accelerator in a mix that contains 400-450kg of cement/m3 of concrete. The product is suitable for use in a variety of applications including road and rail projects where being able to regain possession quickly is extremely important.