Rolled concrete
RCC (including English Roller Compacted Concrete , short RCC ) is an earth-moist concrete , equipped with flat or driving excavators installed and with the aid of rolls is compressed. It is used in the production of road surfaces in the road , the construction of RCC dams in water conservancy and as a structural floor in industrial or warehouse floors. Development began in the United States in the 1980s. Rolled concrete was first used in Germany in 1986.
Rolled concrete has a lower cement content than conventional concrete (80–150 kg / m³). Accordingly, a distinction is made between low cementitious RCC with a cement content of 99 kg / m³ or less and high cementitious RCC with a cement content of up to 150 kg / m³. To keep the heat of hydration as low as possible after setting , pozzolans are added to the rolled concrete .
In road construction , a distinction is made between rolled concrete base layers and rolled concrete base layers:
- Rolled concrete base layers are covered with an asphalt layer,
- Rolled concrete base layers are not built over ( surface layer (also ceiling or road surface) = upper part of the road superstructure )
The rolled concrete is installed with a paver finisher or with a laser-controlled leveling shovel attached to a wheel loader in layers of about 18-20 cm (depending on the load requirement up to 25 cm), pre-compacted and then with a roller with a smooth drum or with compacted by a pneumatic roller . In dam construction, layers of around 30 cm are common.
It is a very common type of construction in the United States. In Germany, this type of construction could not establish itself in road construction, as the quality of the concrete pavement only meets low requirements.
Due to the sometimes coarse surface quality, it is necessary to provide the rolled concrete with an additional top layer for use as an industrial floor. This can be done, for example, with a layer of approximately 2 cm plastic-modified industrial screed . This can alternatively be coated with epoxy resin , but it can also be sanded and treated later.
See also
Web links
Individual evidence
- ^ Helmut Weigler, Sieghart Karl: Concrete. Types - Manufacture - Properties . Ernst & Sohn Verlag, Berlin 1989, ISBN 3-433-01332-2 .
- ^ A b Gerhard Drees : Construction machines and construction methods . Expert-Verlag, Renningen 2002, ISBN 3-8169-2060-8 , p. 188 .
- ^ EK Schrader, J. Lopez, MF Aridah: Mix design and properties of RCC at Mujib Dam - high and low cementitious content . International Symposium on Roller Compacted Concrete Dams, 17. – 19. November, Madrid, Spain 2003, ISBN 90-5809-564-9 , pp. 859-864 .
- ↑ MRH Dunstan: The state-of-the-art of RCC dams in 2003 - an update of ICOLD bulletin No. 125 . International Symposium on Roller Compacted Concrete Dams, 17. – 19. November, Madrid, Spain 2003, ISBN 90-5809-564-9 , pp. 39-48 .