RU2776854C1 - Method for formation of the anchor device of composite reinforcement and anchor device - Google Patents

Abstract

FIELD: construction industry.

SUBSTANCE: invention relates to construction, namely to gripping devices of stretched reinforcement, mainly composite polymer. A method for forming an anchor device of a composite reinforcing rod, including fitting an inventory metal hollow coupling onto the end of the reinforcing rod and filling the coupling cavity with a hardening material, followed by exposure until it hardens. The end of the reinforcing rod is fixed in the coupling by soldering a low-melting alloy with a melting point of at least 25°C below the decomposition temperature of the reinforcing rod binder material, after which the alloy is cooled to solidification to form an anchor device rigidly fixed to the reinforcing rod.

EFFECT: increasing the adhesion strength of the composite reinforcement with the gripping device, simplifying the anchoring process technology, the possibility of repeated use of the anchor device material, the waste-free method.

2 cl, 2 dwg

Description

The present invention relates to construction, namely to gripping devices of fittings, mainly polymer composite.

Known injection ground anchors with extractable thrust.

Various methods are used to free the soil mass from metal rods, including explosive and pyrotechnic methods. The disadvantage of the known designs is the complexity and unreliability, which does not guarantee the extraction of thrust from the ground.

A known method of anchoring the tested composite polymer reinforcement in gripping couplings of a tensile machine and an anchor device (GOST 31938-2012. Composite polymer reinforcement for reinforcing concrete structures. General conditions. Adhesive joints of couplings and composite reinforcement bars according to Appendix B). The ends of the element under test are fixed with a polymer or cement hardening composition in end sleeves, which are metal tubes with covers.

The known method has the following disadvantages: low productivity, since it takes a long time to set the strength of the fill, as well as increased consumption of metal tubes, because. test sleeves may only be used once.

There is a known method of anchoring composite reinforcement in the grips of explosive machines by embedding the ends of the reinforcement in inventory metal sleeves with a melt of modified sulfur (Patent No. 2619298 dated 12/29/2015, publ. The method is quite productive, the cost of sulfur is extremely low. The disadvantage of the known method, adopted as a prototype, is that the process of melting sulfur is quite dangerous, since sulfur ignites when the temperature is accidentally exceeded, molten sulfur emits harmful gases, in addition, hot (140-160 * C) sulfur damages the polymer matrix.

The technical task is to create a method for anchoring non-metallic fiber and composite reinforcement to ensure reliable strong adhesion of the anchor device to the reinforcement without damaging it, as well as to simplify the process technology and the possibility of quick anchoring of the reinforcement immediately before its use (during tensile testing, prestressing on benches, use as inventory traction, etc.).

The technical result consists in creating a waste-free method of fixation and a device that guarantees reliable adhesion of the composite reinforcement to the gripping device, with the possibility of repeated use of the alloy due to its properties (low melting point, rapid strength development, reusability).

The problem is solved in such a way that in the method of forming the anchor device of the reinforcement, which includes fitting a hollow sleeve onto the end of the reinforcement and filling the internal cavity of the sleeve with a hardening material, followed by holding until hardening, according to the invention, the end of the reinforcement 2 is placed in an inventory metal sleeve 1, for example, in the shape of a square tube with a longitudinal slot 3, convenient for soldering and subsequent placement, for example, in the grips of a tensile testing machine.

Then the sleeve 1 is filled with the required amount of molten metal 4 from a low-melting alloy, after which the melt is cooled until solidification with the formation of an anchor device rigidly fixed on the rod 2, and after using the reinforcing rod 2, the metal 4 is melted out of the sleeve 1, the molten metal 4 is drained for reuse.

The proposed method differs from the known one in that at the end of the reinforcement a disposable anchor device is formed from an inventory sleeve and a low-melting alloy, after which the melt is cooled until solidification with the formation of an anchor device rigidly fixed to the reinforcement, and after using the reinforcement, the alloy is melted and drained for reuse.

The proposed device is characterized in that the metal sleeve is made of square or rectangular cross-section with a longitudinal slot and is filled with a fusible alloy to ensure rigid fixation of the end of the reinforcement by soldering.

As the main material for filling the coupling, a fusible alloy is used, for example, Rose alloy (t=96*C) or VladMiVa (t=96*C). This level of short-term heating is acceptable for almost all types of epoxy and other polymer matrices.

The proposed method is implemented in the following technological sequence. The joined parts, for example, the end of a reinforcing bar or rope, are placed in the design position in the coupling cavity. Then, an alloy heated to a temperature of about 100°C is poured into it, which fills the cavity and forms the body of the gripping device. Then produce a smooth cooling of the alloy.

The method and device are illustrated in Fig.1-2, where Fig.1 shows a diagram of the fixation of the composite reinforcement rod in the inventory gripping device of the tensile testing machine; figure 2 is a section along a-a anchor device.

The anchor device of a composite rod, mainly reinforcing, consists of a gripping sleeve 1 of an open square or rectangular section with longitudinal slots, fixed by soldering to the end of the reinforcement 2.

The spent end of the rod 2 is released by simple heating, for example, with a hair dryer, and the melt 4 is drained into a reserve tank.

When using the device in injection anchors, which are manufactured at the factory, and the thrust is released directly in the ground at a depth of 10-20 m, the melting of the alloy is performed by heating the electric coil and wires to the current source.

Example 1

Manufacture of an anchor sleeve for fixing a composite fiberglass rod during testing on a tensile testing machine.

In the internal cavity of the anchor sleeve 1, when testing on a tensile machine, a composite reinforcement rod 2 is placed. The molten alloy 4 fills the cavity of the gripping sleeve 1 through the slot 3, and after cooling and solidification, it rigidly fixes the rod 2 in the body of the anchor sleeve. The length of the coupling is taken at least 15 diameters of the anchored rod.

The proposed method is especially effective for anchoring fiber bundles, ropes and composite polymer reinforcement of a periodic profile, since the melt allows you to apply a load evenly over the entire length of the anchoring.

Sources of information

1 GOST 31938-2012. Composite polymer fittings for reinforcing concrete structures. General terms. Adhesive joints of couplings and composite reinforcement bars according to Appendix B.

2. Patent No. 2619298 Method for forming an anchor device for reinforcement

Claims (2)

1. A method of forming an anchor device for a composite reinforcing bar, which includes placing an inventory metal hollow coupling on the end of the reinforcing bar and filling the cavity of the coupling with a hardening material, followed by holding until it hardens, characterized in that the end of the reinforcing bar is fixed in the coupling by soldering with a low-melting alloy with a melting temperature of not less than 25°C below the decomposition temperature of the reinforcing bar binder, after which the alloy is cooled to solidify with the formation of an anchor device rigidly fixed to the reinforcing bar. 2. An anchoring device for a composite reinforcing bar, including a hollow sleeve mounted on the end of the reinforcing rod, the cavity of which is filled with a hardened material, characterized in that a disposable sleeve of square or rectangular section with longitudinal slots is soldered at the end of the reinforcing rod with a hardened low-melting alloy with a melting point of at least 25°C below the decomposition temperature of the reinforcing bar binder, which is melted and drained for reuse after using the reinforcing bar in the sleeve.

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