RU2758345C1 - Complex unit for determining actual limits of fire resistance of building structures - Google Patents

Abstract

FIELD: firefighting.

SUBSTANCE: invention relates to the field of fire safety, namely to conducting fire tests of flooring panels, floor slabs, coatings, dropped ceilings, load-bearing walls, columns, beams, trusses and other structures. Proposed is a complex unit for determining the actual fire resistance limits of building structures, combining all methods for testing the fire resistance of both horizontal and vertical structures for various temperature conditions of a fire. The complex unit consists of a fire furnace, a combustion chamber, autonomous nozzles, thermocouples, flue gas removal openings, a flue gas removal channel, an exhaust fan. The unit is equipped with a combustion chamber configured to change the volume thereof depending on the loading plan of the tested structure, two longitudinal beams rigidly attached to the furnace, thrust frames attached to the longitudinal beams by means of frame fasteners in the form of tensioning bolts, hydraulic jacks connected with the thrust frames and a movable apparatus for moving thereof in the transverse direction of the furnace, as well as a system for creating and monitoring the temperature conditions of the fire, coupled with the autonomous nozzles and thermocouples, a hydraulic jack control system coupled with the hydraulic jacks, and an exhaust ventilation system coupled with the exhaust fan.

EFFECT: provided production of reproducible and comparable results in determining the limits of fire resistance with minimal time and material consumption.

1 cl, 1 dwg

Description

The invention relates to the field of fire safety, namely to conduct fire tests of flooring panels, floor slabs, coatings, suspended ceilings, load-bearing walls, columns, beams, trusses and other structures for various temperature regimes of fire, which allows with minimal time and materials obtain reproducible and comparable results in determining the limits of fire resistance.

In accordance with Articles 29, 30, 31 of the Federal Law of July 22, 2008 No. 123-FZ "Technical Regulations on Fire Safety Requirements" (as amended by No. 538-FZ of December 27, 2018), buildings and structures must be classified according to the degree of fire resistance, classes of constructive and functional fire hazard. The procedure for determining the degree of fire resistance of buildings, structures is established by Art. 87, according to which the limits of fire resistance of structures must correspond to the accepted degree of fire resistance of buildings and structures. The fire resistance limits of building structures are determined under standard test conditions.

According to Art. 35 the onset of the fire resistance limit of bearing and enclosing building structures under standard test conditions or as a result of calculations is established by the time it takes to reach one or more of the following limit states:

- loss of bearing capacity (R);

- loss of integrity (E);

- loss of thermal insulation capacity (I).

In GOST 30247.0-94 “Building structures. Fire test method. General Requirements ”describes the standard temperature regime of a fire.

The standard temperature regime of a fire is used both for testing and for calculating fire resistance of structures. However, given the specifics of the occurrence and spread of fire in buildings and structures for various purposes, they often resort to the need to use other temperature dependences that reflect the combustion process for specific fire scenarios.

GOST R EN 1363-2-2014 “Building structures. Fire resistance tests. Part 2. Alternative and additional methods ”establishes additional alternative temperature regimes, taking into account the real conditions of the fire and the specifics of the objects.

Currently, the following installations are known for determining the actual limits of fire resistance.

Installation for testing the fire resistance of columns [V.P. Bushev, V.A. Pchelintsev, B.C. Fedorenko, A.I. Yakovlev "Fire resistance of buildings", M., 1963, Publishing house of literature on construction. - 167 p.] (P. 30, fig. 13).

This installation is designed to determine the limits of fire resistance of supporting vertical structures (columns), which consists of a furnace frame, furnace masonry, a sliding fire chamber, a trolley, nozzles, which are designed to create a standard temperature regime of a fire, a smoke channel, furnace thermocouples designed to control the temperature fire mode, base plate, press.

Installation for testing the fire resistance of floors [V.P. Bushev, V.A. Pchelintsev, B.C. Fedorenko, A.I. Yakovlev "Fire resistance of buildings", M., 1963, Publishing house of literature on construction. - 167 p.] (P. 31, fig. 14).

This unit is designed for fire testing of horizontal building structures (floors).

The installation consists of a fire chamber, where in the side walls there are openings for nozzles, which serve to create a standard temperature regime for the fire. A test piece is placed on top of the chamber, for example, a ceiling. A uniformly distributed load in the form of weights is placed on the test specimen.

The disadvantages of these installations are:

- for testing each element (structure), it is necessary to install its own test benches, which lead to an increase in the area of the testing laboratory, and also lead to high economic costs;

- impossibility of conducting fire tests of truss structures, suspended ceilings, decks, ship partitions and load-bearing walls;

- impossibility of carrying out tests for different temperature regimes of fire, different from the standard one.

Closest to the claimed technical solution is the installation for testing the fire resistance of beams, girders, girders "[V.P. Bushev, V.A. Pchelintsev, B.C. Fedorenko, A.I. Yakovlev "Fire resistance of buildings", M., 1963, Publishing house of literature on construction. - 167 p.] (P. 28, fig. 12).

This installation is designed to determine the limits of fire resistance of load-bearing horizontal structures (girders, purlins, beams). The installation consists of a movable frame designed for loading structures, furnace masonry, fire chamber, nozzles, which are designed to create a standard temperature regime for a fire, an air duct, furnace thermocouples designed to control the temperature regime of a fire, masonry of a vault. The movable frame consists of two support clamps, hinged on the adjusting screws, a device of two levers, providing uniform load transfer to the test specimen.

The disadvantages of this installation are:

- impossibility of conducting fire tests of truss structures, suspended ceilings, decks, ship partitions and load-bearing walls;

- impossibility of testing for different temperature regimes of fire, different from the standard;

- a movable frame designed for loading the structures of the installation for testing the fire resistance of beams, girders, girders, is complex, and does not accurately reproduce the design loads during testing;

- also a disadvantage of a mobile frame designed for loading the structures of the installation for testing the fire resistance of beams, girders, girders is the impossibility of loading load-bearing structures other than bent ones.

The objective of the present invention is to create an integrated installation, unified for all test methods, which will allow performing fire tests of both vertical and horizontal load-bearing and non-load-bearing structures according to various loading patterns of the structure and temperature regimes of a fire with minimal time and material costs.

The essence of the claimed installation lies in the fact that a complex installation for determining the actual limits of fire resistance of building structures, consisting of a fired furnace, a combustion chamber, autonomous nozzles, thermocouples, flue gas removal openings, a flue gas removal channel, an exhaust fan, and the installation is equipped with a combustion chamber with the ability to change the volume in accordance with the loading scheme of the test structure, two longitudinal beams rigidly fixed to the furnace, thrust frames with frame fasteners with bolted ties, hydraulic jacks, a test control room, a system for creating and monitoring the temperature regime of a fire, a hydraulic jack control system and a system exhaust ventilation, which allows you to test various types of structures for fire resistance and combines the ability to test various horizontal and vertical load-bearing and non-load-bearing structures with various loading schemes for these structures, as well as to carry out tests for various temperature regimes of fire with minimal economic and labor costs.

The technical effect of the declared complex installation for determining the actual limits of fire resistance of building structures is due to the following:

- the ability to test building structures for fire resistance and their classification in accordance with Federal Law No. 123-FZ of July 22, 2008 "Technical Regulations on Fire Safety Requirements" (as amended by No. 234-FZ of July 13, 2015) on one test bench with minimal economic costs ;

- carry out tests of various structures without applying a load and carry out the process of loading various structures (horizontal and vertical) depending on the loading scheme;

- the possibility of testing structures for alternative temperature regimes of fire, taking into account the real conditions of the fire and the specifics of the object, as well as for the standard temperature regime.

Based on the foregoing, it can be concluded that the claimed technical solution meets the criterion of "inventive step", and the invention itself is new.

The figure shows a general view of a complex installation, which consists of a fired furnace 1, a combustion chamber 2 with a variable volume intended for testing various designs, autonomous nozzles 3 providing a given temperature regime, thermocouples 4 designed to control the temperature regime of a fire, openings for removing flue gases 5, a duct for removing flue gases 6, an exhaust fan 7, two longitudinal beams 8 located on two longitudinal sides of the furnace and rigidly fixed to it, thrust frames 9, fastening frames 10 in the form of bolt ties, hydraulic jacks 11 with a device for moving them into the transverse direction of the furnace, rooms for testing control 12, which includes a system for creating and controlling the temperature regime of a fire 13, a system for loading and controlling hydraulic jacks 14 and an exhaust ventilation system 15.

The complex installation works as follows: in the combustion chamber 2, the volume of the chamber is changed (reduced) for the test scheme of the building element (horizontal or vertical structure). The purpose of changing the volume of the chamber is to create a temperature regime with minimal fuel consumption, depending on the loading scheme of the test structure and its location. After adjusting the volume of chamber 2, a test specimen is installed, after which thrust frames 9 are installed on the stand (the number of frames depends on the loading scheme of the structure), which are attached to the longitudinal beams 8 by fastening the frames 10 in the form of bolt ties 8. In this case, the frames 9 can be attached to different places of the longitudinal beams 8 due to the versatility of fastening the frames 10. Then, using the control system of hydraulic jacks 14 and hydraulic jacks 11, which can move in the transverse direction (the number of jacks is set depending on the loading scheme of the building element), create a load on the structure. Further, using the system for creating and controlling the temperature regime of the fire 13, autonomous nozzles 3 and thermocouples 4, the required temperature regime of the fire is created, shown in the figure. With a decrease in the volume of the chamber, some nozzles 3 do not participate in the test. During the test, using the exhaust ventilation system 15 and the exhaust fan 7, combustion products are removed from the combustion chamber 2 through the openings 5 along the flue gas removal channel 6. Systems 13, 14, 15 are controlled from the test control room 12.

Claims (1)

A complex installation for determining the actual limits of fire resistance of building structures, consisting of a fire furnace, a combustion chamber, autonomous nozzles, thermocouples, flue gas removal openings, a flue gas removal channel, an exhaust fan, characterized in that the installation is equipped with a combustion chamber with the ability to change its volume in dependences on the loading scheme of the test structure, two longitudinal beams rigidly fixed to the furnace, thrust frames that are attached to the longitudinal beams by means of fastening frames in the form of bolt ties, hydraulic jacks connected to the thrust frames and a movable device for their movement in the transverse direction of the furnace , as well as a system for creating and controlling the temperature regime of a fire associated with autonomous nozzles and thermocouples, a hydraulic jack control system associated with hydraulic jacks, and an exhaust ventilation system associated with an exhaust fan.

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