Prefabrication of Reinforcing Bars Using CAD/CAM

In the construction of large-scale structures such as nuclear power plants, an enormous amount of large-diameter reinforcement bars are used, and generally thousands of drawings are required to fabricate them. The installation and fabrication of heavy reinforcng bars are laborious and dangerous for woekers. To facilitate drawing preparation and fabrication work, a CAD/CAM system and an automatic bar arrangement system were developed. The CAD system produces working drawings and the bar code labels conataining bar arrangement data. The automatic bar arrangement system reads the data and arranges straight bars as well as bent bars in a grid shape at the same interval. This system prefabricates 12m long D38 reinforcing bars and forms a 10-ton/unit. The application of the two systems is expected to reduce the labour required for drawing preparation to one fifth and the reinforcing bar fabrication to one half. The entire work productivity will increase to twice of the wholly manual. The systems are presently utilised at a nuclear power plant construction site and 30% of all the reinforcing bars required for construction of the plant is planned to be fabricated by applying the two systems. The systems are expected to contribute to the reduction of construction time and improvement of work safety.