RU2349715C1 - Hollow-core reinforced-concrete slab - Google Patents

Abstract

FIELD: construction industry.

SUBSTANCE: hollow-core reinforced-concrete slab consists of a concrete body with round cavities. Concrete body is reinforced with welded meshes in flanges and with frames in ribs between cavities. The latter have narrowings in the middle of the passage and at both supports. Steel ropes with anchors are located in cavities in turn at supports. Some anchors of ropes bear against the corresponding slab edges, and the other, together with rope sections, are fixed behind narrowings in the middle of slab cavities.

EFFECT: preventing slab parts from falling, after having been damaged during breakdown, earthquake, or bombing, down on expensive equipment and personnel, and providing safety thereof.

3 dwg, 1 ex

Description

The invention relates to the construction and can be used in the construction of buildings with expensive equipment and bomb shelters to shelter people.

Known reinforced concrete panel, consisting of a concrete body with oval voids, reinforced with steel frames located in the ribs, and grids in the shelves [1].

The disadvantage of this panel is the possibility of its collapse during earthquakes and accidents, destruction by debris of expensive equipment, injury and death.

Known reinforced concrete multi-hollow panel, consisting of a concrete body with round voids in sections, reinforced with welded meshes in the shelves and frames in the ribs between the voids [2].

The disadvantage of this panel is the possibility of its collapse during accidents, earthquakes and during bombing and destruction of expensive equipment, injuries and deaths by fragments of the panel.

Closest to the technical solution to the proposed invention is a multi-hollow concrete panel consisting of a concrete body with round voids in sections, reinforced with welded meshes in the shelves and frames in the ribs between the voids [2].

The disadvantage of this panel is the possibility of its collapse during accidents, earthquakes and during bombing and destruction when fragments of the panel of expensive equipment fall, injuring and killing people.

The aim of the invention is to prevent falling parts of the panel after destruction during an accident, earthquake, bombing of expensive equipment and people and ensuring their safety.

To achieve the goal and the specified technical result, the reinforced concrete multi-hollow panel is made of a concrete body with round voids in sections, reinforced with welded meshes in the upper and lower shelves, and welded frames in the ribs between the voids.

Distinctive features of the proposed technical solution is that the voids in the middle of the span of the panel and at both supports have narrowings, and in the voids alternately at the supports there are ropes with anchors at the ends. In this case, one rope anchor abuts against the end of the panel on one support, the rope anchor in an adjacent void abuts against the end of the panel on another support, and so on, and other anchors with a part of the ropes are set for narrowing voids in the middle of the span. This means that each rope has a length greater than half the length of the span of the panel, and the distance of the anchors from the narrowing of voids should provide the arrow of the rope provided for in the calculation after the destruction of the panel and its fragments hanging on the ropes.

Due to the presence of these signs, the expected effect is achieved, consisting in the fact that during an accident or earthquake and the destruction of the panel, the ropes slip and the anchors approach the voids until they abut against the ends of the narrowings in the middle of the span. The panel thus hangs on the ropes forming a hanging single-belt system. Fragments of the panel do not fall on expensive equipment and people, which ensures their safety and prevents death

Figure 1 presents a General view of the panel, figure 2 shows a transverse section of the panel along aa, and figure 3 shows a longitudinal section of the panel bb.

Figure 2 shows the reinforcing mesh 1 and the frame 2. In figure 3 the dashed lines show the ropes 3 with anchors 5 located close to the ends of the panel, and anchors 4, remote from the narrowing of voids in the concrete body at a distance that provides for the calculation arrow single-belt system, which the ropes form when the panel is destroyed, slipping in the constrictions until the anchors 4 come close to the narrowing of the voids. Fragments of the destroyed panel hang on the ropes and do not lead to death and damage to expensive equipment.

An example of the implementation of the proposed technical solution can be a multi-hollow panel measuring 6.4 × 1.2 m 22 cm thick with six voids round in cross sections, used in the overlap between floors of an industrial building with expensive equipment.

With a constant load, g ⁿ = 4.25 kN / m ² , g ^calc = 4.81 kN / m ² and a temporary p ⁿ = 4.0 kN / m ² , p ^calc = 5.2 kN / m ² and full design load P _n ^calc = 10.01 kN / m ^2, the control failure load strength under the assumption that failure will occur in case 1, will be equal to ^{the discharge} _pin P = 10,01 × 1,4 = 14 kN / m ^2.

Assuming that during an accident an already doubled value will be applied to an existing short-term load, we will get 14 + 3.64 × 2 + 21.28 kN / m ² , where 3.64 is a short-term part of the temporary load. Then a load equal to g = 23.41 × 1.2 × 1.1 + 28.1 kn / m will act on the ropes, where 1.2 is the panel width, 1.1 is the dynamic coefficient.

The tension in the ropes capable of absorbing this linear load is T = 348.6 kN (with a sag arrow f = 0.4 m). The total required area of the three ropes at R _un = 140 kn / cm ² will be equal to A _Tr = 1.6 T / K _p R _un = 1.6 × 348.6 / 0.81 × 140 = 4.91 cm ² . We accept 3 ropes (on each side) of the TK GOST 3064-80 type of a single lay ⌀17 / 2.4 with a total area of 5.04 cm ² . To ensure the accepted arrow of the slab after the destruction of 0.4 m, the anchors in the middle of the span should be approximately 4 cm from the ends of the constrictions.

Information sources

1. Baykov V.N., Sigalov E.E. Reinforced concrete structures: General course: Textbook. for universities. - 4th ed. - Moscow: Stroyizdat, 1985 .-- 728 p.

2. Mandrikov A.P. Examples of calculation of reinforced concrete structures. Training allowance for tech. - 2nd ed. - M .: Stroyizdat, 1989 .-- 506 p.

Claims (1)

Reinforced concrete multi-hollow panel, consisting of a concrete body with round voids, reinforced with welded wire mesh in shelves and frames in the ribs between the voids, characterized in that in the middle of the span and at both supports the voids have narrowings, and in the voids, steel ropes with anchors are placed alternately at the supports moreover, some rope anchors abut against the corresponding ends of the panel, and the second with sections of ropes are set for narrowing in the middle of the voids of the panel.

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