SU1310662A1 - Device for determining strain characteristics in concrete slab - Google Patents

Abstract

The invention relates to the field of construction, in particular to the determination of the mechanical properties of building materials. The purpose of the invention is to increase accuracy and reduce test time. The device comprises a base with two supporting posts, a frame with longitudinal rods and clamps for fastening the tested concrete slabs at the ends, and a measuring device. The frame is equipped with a U-shaped bracket with a latch. One of the supporting pillars is equipped with a lever with a roller support that is hinged on it. Clips are made in the form of prisms with springs. The measuring device is made with a strain gauge installed in the hole of the U-shaped bracket. 1 hp f-ly, 2 ill. (L 05 O5 S

Description

ten

11310662

The invention relates to the construction, in particular to the determination of the mechanical properties of building materials.

The purpose of the invention is to show accuracy and reduce test time.

FIG. 1 shows a device common to FIG. 2 is a view And in figure 1

The device comprises a base 1 provided with two support posts 2 with supports 3 on which test sample 4 is mounted, and a frame 5 mounted on the ends of sample 4. The device contains clamps in the form of prisms 6, which slide along the longitudinal bars 7 of the frame 5 and are equipped with springs 8, clamping them of the prism 6 to the ends of the sample 4. On the outer surface of the ends of the frame 5 and perpendicular to it is a U-shaped bracket 9, on which is installed the lock of its position (pin) 10 and the sensor for measuring the deformations. The sensor is made in the form of a dalndra 11 with a groove in which the strain-gauge 12 is installed, and a limiter 13 fixed to the cylinder 1 1 and equipped with a punch 14, one end of which contacts the surface of sample 4 and the other 15

20

, - 25

The frame 5 is fixed on the ends of the test sample 4 using movable acute-angled prisms 6, pressed to the sample by springs 8. The sample is mounted on the supports 3 between their projections so that the latch 10 touches the left support post 2, the Lever 18 with the central roller support 19 and the ball 20 is placed on top of the sample. The strain gauge lattice 12 of the sensor is wired to the instrument (oscilloscope, recorder, etc.). Continuously increasing load is applied to ball 20, for example, from a press. In this case, the sample is bent, and the bending deformation is recorded by the device. On the basis of the obtained results of measuring the maximum deflection deformation under an appropriate load, other deformation characteristics — the flexural and splitting strengths and the elastic modulus — are calculated.

Claims (2)

1. A device for determining the deformation characteristics in concrete slabs, comprising a base with two with strain gauge lattice 12, and support struts, frame with longitudinal rods and clips for fastening at the ends of the tested concrete slabs, and a measuring device, characterized in that, with a price of 15 for outputting wires from a tenz lattice. Domestic strain gauge amplifiers, for example, type TA-5 or KSP-4, four- precision accuracy and reduction of electronic channel recorder of type I-3021-3, test time, frame equipped with P-oscillographs, etc. can be used as a pointer of deformations. equipment. In the figurative bracket with a clamp and decks 2, holes 16 are made for a version, one of the support columns providing U-shaped bracket 9 in them, the wife of a hingedly mounted on it rya their supports 3 are made in the form of rollers with a roller bearing roller , clamps with the protrusions at the ends for fixing the position of sample 4 in the transverse direction. One of the pillars is provided with a bracket 17 on which the lever 18 is pivotally attached, which is connected to a central roller bearing 19 of cylindrical shape, having in its center a recess into which the ball 20 is placed, which receives the load. The device works as follows. ten 15 20 25 The frame 5 is fixed on the ends of the test sample 4 using movable acute-angled prisms 6, pressed to the sample by springs 8. The sample is mounted on the supports 3 between their projections so that the latch 10 touches the left support post 2, the Lever 18 with the central roller support 19 and the ball 20 is placed on top of the sample. The strain gauge lattice 12 of the sensor is wired to the instrument (oscilloscope, recorder, etc.). Continuously increasing load is applied to ball 20, for example, from a press. In this case, the sample is bent, and the bending deformation is recorded by the device. Based on the obtained results of measuring the maximum deflection deformation at an appropriate load, other deformation characteristics are calculated - the limits of flexural and splitting strength, and the modulus of elasticity. Invention Formula 1. A device for determining the deformation characteristics in concrete slabs, comprising a base with two  support posts, longitudinal frame rods and clips for fastening the tested concrete slabs at the ends, and a measuring device, characterized in that, in order to improve accuracy and reduce the test time, the frame is equipped with a U-shaped bracket with a lock and a hole, a hinged arm with a roller bearing on it, the clips are made in the form of prisms with springs, movably mounted on longitudinal rods, and the measuring device is made with a strain gauge installed in the hole of the U-shaped bracket. 2. The device according to p.1.0 t l and h ate, so that the strain gauge is made in the form of a cylinder with a strain gauge, a limiter and a punch. eight 79 20 4 fpue.Z Compiled by V.Malshev Editor K.Voloshchuk Tehred N.Glushchenko Proofreader M.Sharoshi Order 1881/37 Circulation 777 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab, 4/5 - ...... „.., Production and printing company, Uzhgorod, st. Project, 4