RU149570U1 - DEVICE FOR CARRYING OUT TESTS FOR LEVELING FROM CONCRETE WIRE OF COMPOSITE FITTINGS - Google Patents

Abstract

A device for carrying out tests for tearing out a composite reinforcement bar from concrete, consisting of two parts, each of which is made of two angles fastened with studs and plates, and a sleeve for fixing a composite reinforcement bar in it, with a bolt hole made in the center of one plate for holding it in the lower clamps of the tensile testing machine, and in the center of the other plate there is a hole for the rod of composite reinforcement protruding from the concrete cube sample and fixed in the sleeve for holding in the upper clamps tensile testing machine.

Description

The invention relates to devices for testing the tearing out of concrete of a bar of composite reinforcement (fiberglass, basalt-plastic) on a tensile testing machine.

The use of conventional grippers on a tensile testing machine [1] makes it impossible to tear out a bar of composite reinforcement due to its low strength in the transverse direction, which leads to breaking of the bar in the places of fastening.

The objective of the utility model is to prevent breaking of the composite reinforcement bar when tearing it out of concrete.

The technical result is achieved by the fact that the device for testing the tearing out of concrete of a bar of composite reinforcement, consisting of two parts, each of which is made of two angles fastened with studs and plates, and a sleeve for fixing a rod of composite reinforcement in it, and in the center of one the plate has a hole for a bolt to hold it in the lower clamps of the tensile testing machine, and in the center of the other plate there is a hole for a rod of composite reinforcement protruding from a concrete sample-cube, and fixed o in the sleeve for holding in the upper clamps of the tensile testing machine.

In FIG. 1 shows the proposed device for testing the tearing out of concrete bar composite reinforcement; in FIG. 2 shows the arrangement of the device in a tensile testing machine.

The device for testing the tearing of composite reinforcement rods from concrete (Fig. 1) is made of two parts, respectively, 1 and 2. Each part consists of two steel corners 3, fastened by a steel plate 4, and connected to one another by four studs 5. In the center of one (lower) plate, a hole 6 is made for a bolt 7 held in the lower clamps 8 of the tensile testing machine 9 (Fig. 2). In the center of the other (upper) plate, a hole 10 is made for feeding protruding from the concrete sample A of the composite reinforcing bar B fixed in the sleeve 11 for holding in the upper clamps 12 of the tensile testing machine. The plates (upper and lower) are located horizontally.

The proposed device provides during testing the conditions close to the actual working conditions of concrete and reinforcement. The sleeve prevents the bar from breaking in the transverse direction and transfers shear forces to the surface of the reinforcement, which are evenly distributed in the longitudinal forces in its body.

Before testing for tearing out of concrete a bar of composite reinforcement on a tensile testing machine, the following operations are performed.

1. Make, consisting of parts 1 and 2, the device (Fig. 1) for testing the tearing out of concrete bar composite reinforcement. Each part is made of two steel corners (75 × 5 mm) 3, fastened with a steel plate 4 with a thickness of 10 mm. The parts are connected to one another by four studs (M12) 5. In the center of one (lower) plate, a hole 6 for a bolt 7 is made. In the center of the other (upper) plate, a hole 10 is made.

2. Make at least one concrete sample-cube A with a bar B from composite reinforcement. A rod of composite reinforcement is glued into a metal (steel) sleeve 11 using binders or adhesives (e.g., epoxy). To do this, a binder or adhesive is poured into the sleeve, and the sleeve is put on the free end of the reinforcement bar. Sample - The cube is ready for testing after the binder or adhesive has cured.

3. The manufactured device is installed in a tensile testing machine 9 (Fig. 2) so that the bolt is held in the lower clamps 8, and the sleeve threaded from below through the hole in the upper plate is held in the upper clamps 12. To smooth out irregularities on the contact surfaces of the cube sample and the upper plate, between them establish a thin elastic gasket (not shown), made, for example, of rubber or extruded polystyrene foam.

The test of anchoring a bar of composite reinforcement in concrete is carried out on a tensile testing machine, gradually increasing tensile forces. During testing, the lower clamps of the tensile testing machine hold the proposed device, and the upper clamps pull the reinforcing bar out of the concrete cube sample through the sleeve. The end of the test is the complete pulling out of the bar from the concrete sample-cube and fixing the value of the pulling force. The value (magnitude) of the pulling force is used to determine the bond strength of the bar with concrete.

The device for testing the tearing of composite reinforcement rods from concrete eliminates the breaking of the bar during tearing.

The source of information:

1. Rupture testing machine RM-50. Technical description and instruction manual. http://www.testmachines.ru

Claims (1)

A device for carrying out tests for tearing out a composite reinforcement bar from concrete, consisting of two parts, each of which is made of two angles fastened with studs and plates, and a sleeve for fixing a composite reinforcement bar in it, with a bolt hole made in the center of one plate for holding it in the lower clamps of the tensile testing machine, and in the center of the other plate there is a hole for the rod of composite reinforcement protruding from the concrete cube sample and fixed in the sleeve for holding in the upper clamps tensile testing machine.

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