More slender and more sustainable cast stone blocks with UHPCs

Figure: Ducon GmbH

Fig. 1: 40th Precinct police station, Bronx, NYC

Figure: Ducon GmbH

Fig. 2: Panels up to 9.25 m, 50 mm thickness

Figure: Ducon GmbH

Dr.-Ing. Stephan Hauser;

Ducon GmbH, Darmstadt

s.hauser@ducon.eu

Construction material

Ducon (DUctile CONcrete) combines ultra-high-strength concrete with spatial micro-reinforcement to produce an innovative, ductile and load-bearing high-performance concrete. For this reason, Ducon is used as safety, architectural and design concrete, for subsequent strengthening of buildings and in resistant industrial floors and surfaces that meet the regulations of the German Water Management Act (WHG). The material properties can be adjusted according to the technical requirements.

Ducon highlights

Very thin self-supporting concrete staircases (folding staircases, story-high, 8 cm)

Very thin roof shells (“Parapluie” 25-35 mm, Tsuboi Award 2013)

Thin, energy-efficient building shells, elements 11 m long and 50 mm thin, thermally activated (ETA factory)

Thin concrete house, 30 mm wall and roof thickness (“House in the Vineyard”)

Thinnest solution for explosion protection (new World Trade Center in New York)

Jointless industrial floors and thin layers according to the German Water Management Act (WHG) 35-60 mm (up to 15,500 m² jointless).

Sustainable building

Properties of these construction materials − such as slight thickness of building elements together with great loadbearing capacity, high energy absorption, great durability and, accordingly, long service life – are key elements for sustainable building with concrete.

Ducon can save up to 70 % in the thickness and in the weight of a building element: e.g., for façades in comparison to conventional reinforced concrete. Other benefits include reduced number of transports, thinner substructures, smaller lifting equipment, material savings for adjoining building structures, etc.

Furthermore, ultra-high-strength eco-concrete (DuconGreen1) has been developed for this system that enables up to 70 % reduction of Portland cement clinker and compressive strengths of approx. 150 N/mm² as well as minimal carbonation depth. These result in further reduction of harmful environmental impacts.

This approach combines the benefits of UHPC as eco-concrete with recycled micro-reinforcement of carbonless and non-corrosive steel.

The product declarations and eco-balances of this high-performance construction material attest to significant reduction of CO₂greenhouse emissions compared to conventional reinforcing steel and building elements with carbon reinforcement.

Until now, 400 projects have been implemented with this resource-preserving and eco-friendly technology.