RU2527263C1 - Device to control strength of reinforced concrete structures - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: device to control strength of reinforced concrete structures comprises a power frame from rods and cross bars fixed on it by means of nuts, a cross beam with aligning supports, a hydraulic jack. The device also comprises an additional crossbar, an additional cross beam, a cargo cantilever with a level and safety racks fixed to fixed crossbars. At the same time the additional crossbar is arranged between fixed upper and lower crossbars as capable of movement under low forces by means of nuts and thrust bearings, arranged between the upper nut and the crossbar, and under higher ones - with the help of the jack installed on it, besides, one end of the cargo cantilever is arranged between crossbeams, and the second one - equipped with a cargo platform. Besides, to test the beams for cross bending, one sample is laid onto the lower crossbar, and the second one - onto the upper cross beam with support onto the additional crossbar via aligning supports arranged with rated eccentricity.

EFFECT: production of valid results during testing of samples for cross bending or longitudinal compression under various loading patterns both during long-term and short-term ones, as well as during long-term creep tests.

2 cl, 2 dwg

Description

The invention relates to the field of testing building materials and structures, and in particular to a technique for controlling the quality of materials and studying their deformation properties.

Known experimental installation for testing beam structures, containing a temporary collapsible stand, a loading device in the form of a standard press, a force measuring device and supporting structures / Patent RF 2351910 Experimental installation for testing beam structures. / Orel State Technical University; Kolchunov V.I., Skobeleva E.A. - application No. 2007142054, - declared. November 13, 2007, publ. 04/10/2008 /.

The disadvantage of this device is that during a long test mode, when the inelastic properties of reinforced concrete are manifested (deformation without changing load - creep), the use of a hydraulic standard press requires special software to maintain a constant force. Manual force control does not provide reliable results in lengthy tests. The disadvantage of this device is the impossibility of its placement in a climatic chamber for testing with a constant temperature and humidity conditions, which is necessary when testing samples. In addition, the proposed device is designed to test only one sample.

The closest in technical essence and the achieved technical result to the proposed invention is an experimental setup consisting of a power frame, a hydraulic jack to create effort, cords and crossbar. Such a setup is compact, allows you to observe the development of deflections and cracks in the sample during short-term tests and can be placed in a small climatic chamber / Installation for testing beams for bending. In the book. G.V. Murashkina, A.I. Snegireva - Laboratory workshop on reinforced concrete and stone structures: a textbook for universities. -M.: DIA Publishing House, 2006. - P. 9. fig. 2.1. and 2.2 /. Adopted for the prototype.

The disadvantage of this experimental setup is the ability to test only one sample, with the creation of efforts by a hydraulic jack that cannot be kept constant without complex automated control during lengthy tests.

The essence of the invention is the simplification of the test process, the reduction of errors during testing of samples, simplifying the design of the installation for testing, expanding its operational capabilities and simplifying its maintenance.

The technical result of the invention is to obtain reliable results when testing samples for transverse bending or longitudinal compression under various loading schemes for both long and short-term, including long-term creep tests.

The technical result is achieved by the fact that the known device for monitoring the strength of reinforced concrete structures, including a power frame of rods and bolts fixed to it, crossbars with centering supports, a hydraulic jack, contains an additional crossbar, an additional crosshead, a cargo console with a level and safety rails attached to the fixed crossbars, with the additional crossbar located between the fixed upper and lower crossbars with the possibility of movement with small efforts ohm nuts and thrust bearings located between the upper nut and the bolt, and for large ones - with the help of a jack installed on it, with one end of the cargo console located between the traverses, and the other equipped with a loading platform; in this case, to test the beams for transverse bending, one specimen is laid on the lower crossbar, and the second on the upper beam with support on the additional crossbar through the centering supports located with the calculated eccentricity.

For longitudinal compression tests, the samples are mounted vertically one above the other with support through centering supports with calculated eccentricity at one end of the load arm, free of the load platform, between the lower and additional crossbars.

The invention is illustrated in figure 1 and figure 2.

Figure 1 shows the installation for monitoring the strength during the tests for transverse bending of reinforced concrete beams for short and long loads, where the following notation is accepted: rod - 1, nut - 2, upper bolt - 3, middle bolt - 4, lower bolt - 5 , thrust bearings - 6, sample - reinforced concrete beam - 7, load - 8, load bracket - 9, upper beam - 10, lower beam - 11, centering support - 12, hydraulic jack - 13, safety rail - 14, cargo platform - 15, level - 16.

Figure 2 shows the installation of strength control during testing for longitudinal compression of concrete prisms, where marked: hydraulic jack - 13, level - 16, sample - concrete prism - 17.

Information confirming the possibility of carrying out the invention.

Test samples for transverse bending with short-term and long-term loads (Figure 1).

On the four rods 1, with the help of nuts 2, the upper crossbar 3, the middle crossbar 4 and the lower crossbar 5 are fixed. Thrust bearings 6 are installed between the upper nuts 2 and the middle crossbar 4, which provide adjustment of the position of the middle crossbar 4 with little effort on the tested bent samples - reinforced concrete beams 7.

Before the test, a sample is first installed - a reinforced concrete beam 7 with centering supports 12 on the lower crossbar 5, a lower beam 11 with centering supports 12 is installed on it. Next, a load bracket 9 with centering supports 12 is installed on the lower beam 11, which is supported when installed horizontally . Then, the upper beam 10 is installed on the cargo console 9 with centering supports 12, and another sample is installed on it - a reinforced concrete beam 7, which is pressed through the centering supports by the middle crossbar 4. The centering supports are located with a calculated eccentricity. To exclude the loss of stability from the plane when installing specimens - reinforced concrete beams 7 or when they are destroyed during the test, safety rails 14 are attached to the upper crossbar - 3 and the lower crossbar - 5 with a gap in relation to the tested samples.

After installing the test samples - reinforced concrete beams 7, the estimated mass of cargo 8 is installed on the loading platform 15. As the samples are loaded, the reinforced concrete beams 7 bend and the load console 9 deviates from the horizontal position. To maintain the cargo console 9 in a horizontal position with small efforts, the middle bolt 4 is moved with the nuts 2, achieving the horizontal position of the cargo console 9 using level 16. The position of the middle bolt 4 and the cargo console 9 is fixed at low loads by simply tightening the nuts 2, which is facilitated thrust bearings 6. When carrying out significant loads, the position of the middle bolt is adjusted using a hydraulic jack 13. Maintaining the load console 9 in a horizontal position SRI is necessary for transmission in the samples only vertical force.

The loading of the samples - reinforced concrete beams 7 is carried out by means of static force from the load 8, transmitted by means of the load console 9 to the upper beam 10 and the lower beam 11 through the centering supports 12.

The test samples for longitudinal compression at short and long-term loads (Figure 2).

To test the samples for longitudinal compression, the samples are mounted vertically one above the other between the lower and additional crossbars. Each sample at one end abuts through a centering support with calculated eccentricity on the end of the cargo console free from the loading platform. Loading samples and maintaining the cargo console in a horizontal position is the same as when testing samples for lateral bending.

The advantages of the invention:

- The proposed device for testing is compact and allows you to analyze the condition of two reinforced concrete samples that are in the same climatic and temporal conditions for a long period, loaded with constant static load, with the adjustment of the position of the cargo console and crossbars.

- The use of a static load provides accurate experimental test data for samples with various loading schemes, including long-term creep tests.

- The use of thrust bearings allows to improve the centering conditions of the samples, select an idle stroke and align the position of the cargo console at low loads.

- The use of a hydraulic jack allows alignment of the position of the cargo console with significant loads.

Claims (2)

1. A device for monitoring the strength of reinforced concrete structures, including a power frame of rods and bolts fixed to it with a bolt, a beam with centering supports, a hydraulic jack, characterized in that it contains an additional bolt, an additional beam, a cargo console with a level and safety rails, attached to the stationary crossbars, with an additional crossbar located between the fixed upper and lower crossbars with the possibility of movement at low forces by means of nuts and thrust bearings, aspolozhennyh between the top nut and bolt, and at high - with the jack mounted thereon, wherein one end of the cargo console located between the cross members and the other - equipped with a load platform; in this case, to test the beams for transverse bending, one specimen is laid on the lower crossbar, and the second on the upper beam with support on the additional crossbar through the centering supports located with the calculated eccentricity. 2. The device according to claim 1, characterized in that, for longitudinal compression testing, the samples are mounted vertically one above the other with support through centering supports with calculated eccentricity at one end of the cargo console, free from the cargo platform, between the lower and additional crossbars.

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