GOST 23119-78

Group Zh34

STATE STANDARD OF THE UNION OF THE SSR

WELDED STEEL ROOF TRUMS WITH ELEMENTS
FROM PAIR CORNERS FOR INDUSTRIAL BUILDINGS

Specifications

Steel welded roof panties of double angles
for industrial buildings. specifications.

Valid from 01.01.1979
until 01.01.1984*
______________________________
* Expiry date removed
Gosstandart Decree
No. 353 dated 29.02.84. - Note
database manufacturer.

APPROVED AND INTRODUCED BY Decree of the State Committee of the Council of Ministers of the USSR for Construction of April 28, 1978 N 73

REPUBLICATION. November 1979


This standard applies to steel welded truss trusses with elements from paired corners connected into Taurus, with an upper chord slope of 1.5%, intended for industrial buildings with spans of 18, 24, 30 and 36 m:

with rolled and mastic roofing;

with steel and reinforced concrete columns;

with non-aggressive and slightly aggressive environments;

erected in areas with an estimated outdoor temperature of minus 65 ° C and above and seismicity up to 9 points inclusive.

Roof steel trusses must meet the requirements of GOST 23118-78 and the requirements set forth in the relevant sections of this standard.

1. Main dimensions

1. Main dimensions

1.1. Farms should be made in height:

3150 mm - for spans of buildings 18, 24, 30 and 36 m;

2250 mm - for spans of buildings 18 and 24 m.

Trusses with a height of 3150 mm for building spans of 18 and 24 m should be used in buildings in which, along with spans of 18 and 24 m, there are spans of 30 and 36 m, as well as in buildings where, according to the conditions of production technology, an increased height of the inter-truss space is required. In other cases, the choice of trusses in height for building spans of 18 and 24 m is made on the basis of the results of a comparison of the technical and economic indicators of the considered options.

1.2. Schemes and basic dimensions of trusses must correspond to those indicated in Fig.1. It is allowed to use additional elements of the lattice (sprengels, elements for fastening the ways of overhead transport, racks to reduce the estimated length of the main rods of trusses, etc.).

1.3. The division of farms into shipping elements must comply with drawing 2.

SCHEMES AND BASIC DIMENSIONS OF FARMS

DIVISION OF FARMS FOR SHIPMENT ELEMENTS

Trusses for spans of buildings 18 m

a) sent in one element
allowed

Trusses for spans of buildings 24 m

Trusses for spans of buildings 30 m

Trusses for spans of buildings 36 m

2. Technical requirements

2.1. Trusses must be manufactured in accordance with the requirements of this standard, GOST 23118-78 and SNiP III-18-75, according to working drawings of KMD approved in the prescribed manner.

2.2. The maximum deviations of the linear dimensions of trusses and their parts from the nominal ones are given in Table 1.

Table 1

2.3. The limiting deviations of the shape and location of the surfaces of truss parts from the design ones are given in Table 2.

table 2

2.4. The roughness of the machined end surface of the support rib should not be rougher than the first class according to GOST 2789-73.

2.5. The distance between the edges of the lattice details and belts in the truss nodes should be equal to 4-5 gusset thicknesses.

2.6. The upper belts of trusses with a thickness of belt corners of less than 10 mm in the places where reinforced concrete slabs are supported must be reinforced with overlays.

2.7. On the upper plane of the corners of the upper chords of the trusses, in the case of reinforced concrete slabs resting on them, transverse risks should be applied with indelible paint, indicating the center of the node.

2.8. Truss parts, depending on the design temperature, must be made of steel grades given in Table 3.

2.9. Welded joints of truss elements must be made mechanically.

It is allowed, in the absence of equipment for welding by mechanized methods, the use of manual welding.

Table 3

Notes:

1. Steel grades must be accepted according to SNiP II-B.3-72 and SNiP II-28-73.

2. Option 1 or 2 is selected based on the results of comparing their technical and economic indicators.

2.10. Materials for welding should be taken in accordance with SNiP II-B.3-72.

2.11. Trusses must be primed and painted.

Priming and painting must comply with the fifth class of coverage in accordance with GOST 9.032-74.

3. Completeness

3.1. Farms must be supplied by the manufacturer as a complete set.

The kit should include:

sending elements of farms;

mounting gaskets with a thickness of 4, 6 and 8 mm in an amount equal to 85, 65 and 20%, respectively, of the total number of truss support nodes;

technical documentation in accordance with the requirements of GOST 23118-78.

4. Acceptance rules

4.1. Trusses (shipping elements) to check their compliance with the requirements of this standard must be accepted by the technical control of the manufacturer individually.

4.2. The control of deviations of the linear dimensions of trusses and their parts (including the cross-sectional dimensions of rolled profiles) from the nominal ones, deviations of the shape and location of the surfaces of parts from the design ones, the quality of welded joints and surface preparation for protective coatings should be carried out before priming the trusses.

4.3. The first and every tenth farm should be subjected to a control assembly.

4.4. The consumer has the right to accept the trusses, while applying the acceptance rules and control methods established by this standard.

5. Control methods

5.1. The control of deviations of the linear dimensions of trusses and their parts from the nominal ones, deviations of the shape and location of the surfaces of parts from the design ones, as well as the roughness of the machined surface should be carried out by universal methods and means.

5.2. The quality control of the seams of welded joints and the dimensions of their sections should be carried out in accordance with SNiP III-18-75.

6. Marking, transport and storage

6.1. Manufactured trusses must be marked.

On each sending element of the farm must be applied:

Order number;

number of the KMD drawing, according to which the sending element of the truss is made;

symbolic designation of trusses according to the KMD drawing indicating the production serial number.

Each package of mounting gaskets must be marked with the order number and the number of the KMD drawing according to which the gaskets are made.

Each mounting gasket must be marked with its thickness.

An example of marking the sending element of the farm:

where 310 is the order number;

5 - KMD drawing number;

B8 - symbol;

6 - serial number of production.

On the sending element of the truss, markings must be applied on the first brace and on the outer plane of the lower chord, as well as on the package of mounting gaskets - at the top and bottom of the package.

Markings must be applied with indelible paint.

6.2. Farms (shipping elements) must be transported and stored in working position. At the same time, the trusses must be supported by wooden linings installed near the nodes, at least 50 mm thick during transportation and at least 150 mm when storing the trusses at the construction site.

The length of the lining must exceed the width of the lower chord of the trusses by at least 100 mm.

During transportation and storage, the reliability of fixing the trusses and their safety from damage must be ensured.

During transportation, the sending elements of farms must be combined into packages. The mass of the package must be agreed with the consumer and not exceed 20 tons.

Mounting gaskets must be bundled with wire.

7. Installation instructions

7.1. Truss installation must be carried out in accordance with the requirements of GOST 23118-78 and SNiP III-18-75.

7.2. Limit deviations from the design position of the mounted structures are given in Table 4.

Table 4

7.3. The displacement of the outer edges of the supporting parts of the reinforced concrete pavement slabs from the transverse marks applied in accordance with clause 2.7 should not be more than 20 mm.

8. Manufacturer's warranty

8.1. The manufacturer must ensure that trusses comply with the requirements of this standard, subject to the conditions of transportation, storage and installation established by this standard.



Electronic text of the document
prepared by Kodeks JSC and verified against:
official publication
M.: Publishing house of standards, 1982

Reinforced concrete trusses are used for spans of 18, 24 and 30 m (rarely 36 l); subdivide them into segmental, arched, triangular, trapezoid and with parallel belts (Fig. 64). Depending on the manufacturing method, trusses can be solid, from semi-trusses, from blocks 6 m long and from individual elements.

Segmental, arched and polygonal trusses are designed for roofing with rolled roofing, triangular - for roofing of asbestos-cement and metal corrugated sheets. Farms with parallel belts are used in buildings with a flat coating under a rolled "dry" or water-filled roof.
To avoid a large slope of the roof in the extreme panels on the supports of the segmental trusses, small posts are provided to support the roofing panels. Truss step 6 and 12 l (rarely 18 m).

The lattice of trusses allows supporting panels with a width of 1.5 and 3 m. In case of out-of-node support of panels, the upper chord is additionally reinforced to absorb forces from local bending. Most pitched trusses have support nodes 0.8 m high.
Farms are made of concrete grades 300-500. The lower belt is prestressed and reinforced with bundles of high-strength wire. To reinforce the upper belt, braces and racks, welded frames made of hot-rolled steel of a periodic profile are used. In fems, embedded elements are provided, similar to beams.

The most rational in terms of material distribution are segmental and arched trusses with a broken or curvilinear upper belt. Compared to others, they have lower forces in the lattice elements and smaller bending moments in the upper chord from out-of-node loading, which makes it possible to make the lattice more sparse. Segment and arch trusses have a small height on the support, which allows to reduce the height of the walls; however, the curvilinearity of the upper chord complicates the formwork and reinforcement.

Rice. 64. Reinforced concrete roof trusses:

The configuration of the top chord of the trapezoidal trusses is simple, they are interchangeable with steel trusses. The disadvantages of such trusses include: a relatively powerful lattice, a large height on the support, which requires the installation of vertical connections between the trusses in the plane of the support posts; these trusses are somewhat heavier than segment trusses.
Compared to others, trusses with parallel belts consume more materials, but the formwork used for their manufacture is simple and less labor intensive.

The trusses are fastened to the columns and to the sub-rafter structures with anchor bolts and welding of embedded supporting elements (similar to the fastening of reinforced concrete beams).