SU131488A1 - Device for electrothermal tensioning of rod-supplied reinforced concrete products at the ends of heads - Google Patents

Description

Various devices for tensioning reinforcement of prestressed reinforced concrete structures by mechanical means are known. The electrothermal method of tensioning the reinforcement is also known.

Mechanical tensioning of the reinforcement is time consuming and requires highly qualified staff. The equipment used with this tensioning method is cumbersome and expensive. The use of the electrothermal method of tensioning the reinforcement until 1957 was limited, due to the lack of the developed technology and devices for heating and controlling the tension of the reinforcement.

The proposed device makes it possible to widely apply the electrothermal method of tensioning the reinforcement in the form of rods or bundles with the transfer of the tension on the form supports to concreting. In this case, the above-mentioned disadvantages of the mechanical method of tensioning the reinforcement of pre-stressed reinforced concrete structures are eliminated. Compared to the existing installations for tensioning the reinforcement by electrothermal method, the proposed device also has the advantages that the reinforcement is heated to its full length from stop to stop. This makes it possible to uniformly improve the properties of the reinforcement along its entire length.

The drawing shows the proposed device in two projections.

The device consists of a frame /, a form 2, grippers 3, a movable carriage 4, an adjustable stop 5 and a limit switch 6, for 7, for DL transformers. The movable carriage 4 is moved in the guides 8 by means of pneumatic cylinders 9. The device carries out

№ 131488

electrical heating, support and laying in the rod shaped supports 10. The grippers 3 are insulated from the carriage 4 and can be moved in the longitudinal direction (together with the carriage) and in the transverse direction.

Reinforcing rods, prepared in shorter form for the required amount of elongation - D / are laid in the form stops on the side opposite to the movable carriage. On the other hand, the molds J of the carriage 4 are superimposed on them. Air is supplied to the pneumatic cylinders and they move the carriage 4 away from the grippers 3. The rods slightly tighten to avoid sag and to create reliable contact in the grips and stops of the molds. Then a current is applied to the rods, they are heated (within 1-2 minutes) and an elongation is obtained, which is selected due to the movement of the carriage from the mold under the action of pneumatic cylinders. When the rods have the required elongation, the carriage will touch the end switch, turn off the current supplied to the rods, and turn off the air. The carriage receives a return movement, while the rods, released in the grippers, under the action of its own weight, are fed into the slots of the front stop of the form.

Subject invention

A device for electrothermal tensioning of a rod equipped with ends at the ends, reinforcement of reinforced concrete products manufactured in metal forms with end stops, characterized in that, in order to increase the degree of mechanization of the process, a form installed at the end and moved in the longitudinal direction using pneumatic and such cylinders are a carriage with grippers designed to pick up the slacks of the rods during the heating process, as well as to ensure tight contact between the rod head and ortsovym emphasis form.