Concrete-Carbon Fibers 68mE Research Update
Chemical research have built pavilions with a wall thickness of just a four centimeters. They consist of fiber-reinforced concrete. This material is design to replace once reinforced concrete for highway bridges. Rust free structures stand for extremely life. There is no need to paint them or maintain.
3.5 meters high and just times four centimeter thick are the concrete pavilions which are recently on the sports field of the Chemistry Technical University. Were they from conventional building materials the delicate fabric would be immediately collapsed after the. That it doesn’t is a special construction. A clutch of carbon fibres inside covers the dynamic forces of high-performance concrete that standard concrete solution can not catch up.
Typically, components made of concrete with steel mesh or cords are reinforced. But they can, if the concrete is damaged, corrode and compromise, for example, the capacity of all highway bridges. With concrete of carbon can happen, because the carbon fibers are resistant against environmental influences.
68 million euros research funding for better building materials.
The team led by Professor Sandra Gelbrich, Director of the Division of “Lightweight Construction”, is part of the initiative “C3 – Carbon Concrete Composite”. Their target is a construction material where the corrosion sensitive steel reinforcement will be replaced by a combination of carbon fibre, textile structures and concrete. The project is supported by 40 companies and research institutions. The Federal Research Ministry has made loosely €45 million for it. There are also 23 million €, which contribute to the companies involved.
Black Carbon Fibers looks like a silk.
The scrim of carbon fibers consists of crosswise superimposed Rovingen, are bundles from each 50,000 fibers. “You feel like black silk”, says Andreas Ehrlich, which is part of the Sara team. Therefore, the researchers like to speak of textile reinforcement. A form of glass fiber composite material is used as external form-work. The first layer of concrete is to split. In the still-wet concrete, the engineers press the first layer of scrim. So, the Pavilion is built layer by layer and freed after curing of the form-work.
“This is a lot of hand work,” says Ehrlich. Researchers have already devised a technique to manufacture industrial mouldings. To do this, the scrim with spacers in a closed formwork is placed. Then, they pour liquid concrete which is offset with small stones.
Roads could be ice-free
The Pavilions have been equipped with an interior light from light-emitting diodes. They are activated with a proximity switch integrated into the concrete. The construction allows to integrate other sensors that measure, for example, the load. That would be interesting for bridges. Heating wires can infuse himself around on the concrete roadways in the winter ice to keep.