Foreword

TCVN 9311-4:2012 is completely equivalent to ISO 834-4:2000.

TCVN 9311-4:2012 has been converted from TCXDVN 344:2005 (ISO 834-4:2000) in accordance with Clause 1 Article 69 of the Law on Standards and Technical Regulations and Point a) Clause 1 Article 7 of the Decree 127/2007/ND-CP dated 01/8/2007 detailing the implementation of some articles of the Law on Standards and Technical Regulations.

TCVN 9311 series under the general title “Fire-resistance tests – Elements of building construction” includes the following parts:

• TCVN 9311-1:2012, Part 1: General requirements
• TCVN 9311-3:2012, Part 3: Commentary on test method and application of test data
• TCVN 9311-4:2012, Part 4: Specific requirements for loadbearing vertical separating elements
• TCVN 9311-5:2012, Part 5: Specific requirements for loadbearing horizontal separating elements
• TCVN 9311-6:2012, Part 6: Specific requirements for beams
• TCVN 9311-7:2012, Part 7: Specific requirements for columns
• TCVN 9311-8:2012, Part 8: Specific requirements for non-loadbearing vertical separating elements

The ISO 834 series Fire-resistance tests – Elements of building construction also includes the following parts:

• ISO 834-9:2003, Fire-resistance tests – Elements of building construction – Part 9: Specific requirements for non-loadbearing ceiling elements
• ISO/DIS 834-10, Fire-resistance tests – Elements of building construction – Part 10: Specific requirements to determine the contribution of applied fire protection materials to structural elements
• ISO/DIS 834-11, Fire-resistance tests – Elements of building construction – Part 11: Specific requirements for the assessment of fire protection to structural steel elements

TCVN 9311-4:2012 is drafted by the Institute for Architecture, Urban and Rural Planning – Ministry of Construction, proposed by the Ministry of Construction, appraised by the Directorate for Standards, Metrology and Quality, and promulgated by the Ministry of Science and Technology.

1. Scope

This standard specifies the procedures to be followed for determining the fire resistance of loadbearing vertical separating elements when exposed to fire on one face.

The results of the tests conducted according to this standard may apply to similar elements not subjected to testing if they meet the field of direct application given in different parts of this standard or when extended application is used in accordance with ISO/TR 12470. Since ISO/TR 12470 only provides general guidance, analysis of extended application for a specific case should only be conducted by experts in fire-resistant construction.

2. Normative references

The following normative references are indispensable for the application of this standard. For dated references, only the cited edition applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

TCVN 9311-1:2012 ¹⁾, Fire-resistance tests – Elements of building construction – Part 1: General requirements.

TCVN 9311-3:2012 ¹⁾, Fire-resistance tests – Elements of building construction – Part 3: Commentary on test method and application of test data.

ISO/TR 12470, Fire-resistance tests – Guidance of the application and extension of results

ISO/IEC 13943, Fire safety vocabulary

3. Terms and definitions

For the purposes of this standard, the terms and definitions given in TCVN 9311-1:2012, ISO 13943 and the following apply:

3.1. Vertical separating elements

Loadbearing elements of a building oriented vertically, which act as fire separating or fire shielding elements. These elements divide the building into fire compartments or fire cells, or separate the building from adjacent buildings, in order to restrict the spread of fire to other compartments or adjacent buildings.

3.2. Wall

Loadbearing vertical separating element of a building structure that carries load.

4. Symbols and abbreviated terms

For the purposes of this standard, the symbols and abbreviated terms given in TCVN 9311-1:2012 apply.

5. Test apparatus

The apparatus used for the test includes the furnace, loading equipment, boundary conditions and instrumentation as specified in TCVN 9311-1:2012. An example of a test is shown in Figure 1.

KEY

Figure 1 – Example of a loaded vertical assembly test setup

6. Test conditions

6.1. General

The heating and pressure conditions, the furnace atmosphere and the loading conditions shall comply with the requirements specified in TCVN 9311-1:2012.

6.2. Boundary conditions and restraint

Boundary conditions and restraint shall comply with the requirements specified in TCVN 9311-1:2012 and the requirements of this standard.

6.3. Loading

6.3.1. All loadbearing vertical separating elements shall be tested under the load calculated according to 6.3.a) or c) of TCVN 9311-1:2012, in consultation with the test sponsor to produce conditions appropriate to the element as designed. The material properties used in the load calculation shall be clearly indicated including their sources. For vertical separating elements containing components that support negative loads, the load shall be proportional to the number of those components.

6.3.2. When the height of the specimen proposed exceeds the suitable height of the test furnace, the load shall be adjusted to correspond to the ratio between the slenderness of the loaded element of the specimen and the load of the full-sized structure provided.

6.3.3. The vertical load shall be applied at either the top or bottom edge. All edges not restrained shall be sealed with non-combustible, non-restraining material.

6.3.4. The load shall be applied uniformly across the width of the specimen through a loading beam or individual loading jacks at selected points, where this better represents the end use of the element. Where the specimen is designed to support eccentric loading or to support load on one face only of a hollow element, such conditions shall be reproduced in the specimen.

6.3.5. When uniformly distributed loading is used, the specimen shall be installed within a loading frame of a stiffness appropriate to the element under test and the loads applied to it during the test. As guidance, the members used to distribute the load should not deflect more than 1 mm under a force of 10 kN applied at midspan in the plane of the frame.

6.3.6. The loading system shall be capable of accommodating the maximum anticipated deflection of the specimen.

6.3.7. When both leaves of a double-leaf wall support load, loading of each leaf independent of the other shall be taken into account. The loading apparatus shall be capable of imposing different magnitudes of load from one leaf to the other where appropriate.

7. Test specimen preparation

7.1. Specimen construction

The specimen shall be constructed with the structural features designed to achieve the desired performance that the specimen is intended to represent.

When vertical separating elements incorporate building services (e.g. electrical socket outlets and concealed wiring) which are an integral part of the element design, they shall be incorporated into the specimen.

7.2. Size of specimen

The specimen shall be full size when the actual element is up to 3 m high or up to 3 m wide. For specimens over 3 m x 3 m size of the test furnace, the minimum size of specimen exposed to the fire shall be not less than 3 m x 3 m.

7.3. Number of specimens

For symmetrical elements, only one specimen is required unless otherwise specified in this standard. For non-symmetrical elements, the number of specimens shall comply with the requirements of this standard and TCVN 9311-1:2012.

7.4. Conditioning of specimen

At the time of the test, the strength and moisture content of the specimen shall be approximately as expected in normal service. This includes bedding and jointing materials. Guidance on conditioning test specimens is given in TCVN 9311-1:2012. Once equilibrium has been established, the moisture content or state of cure shall be determined and recorded. Supporting constructions including the lining of the furnace in the test frame are not subject to this requirement.

7.5. Installation of specimen and restraint

The specimen shall be installed with its vertical edges free to deflect unless otherwise requested by the test sponsor.

When the specimen is smaller than the opening of the test frame, a supporting construction shall be used to reduce the opening to the required size. The supporting construction is not required to follow the conditioning requirements for the specimen unless it contributes to the specimen’s performance. Where a supporting construction is used, the design of the junction between the separating element and the supporting construction, including any fixing details and materials used to form the junction, shall be as used in practice and shall be considered as part of the specimen. The supporting construction shall be considered part of the test frame. An example of a supporting construction in a test design is shown in Figure 2.

If a junction between the specimen and supporting construction including test frame is used, it shall reproduce normal levels of restraint appropriate for the end use. The stiffness of the supporting construction shall also reproduce the normal levels of restraint appropriate for the end use.

8. Installation of instrumentation

8.1. Furnace thermocouples

Thermocouples shall be provided to measure the furnace temperature and shall be distributed to obtain a reliable indication of the average temperature over the exposed face of the test specimen. The thermocouples shall be mounted and positioned as specified in TCVN 9311-1:2012.

The number of thermocouples shall be not less than one per 1.5 m² of the exposed face area of the test specimen. There shall be a minimum of four thermocouples for any test and each shall have its “A” face pointing towards the back wall of the furnace.

KEY

Figure 2 – Example of a supporting construction in a loaded assembly test

8.2. Unexposed face thermocouples

Unexposed face thermocouples shall be attached and positioned in compliance with TCVN 9311-1:2012. For the determination of maximum temperatures, unexposed face thermocouples shall be placed no closer than 100 mm to any edge at the following locations, when they occur:

a) At a head of the test specimen and at mid-width;

b) At a head of the test specimen in line with a stud/post;

c) At the intersection of a stud and a noggin in a non-loadbearing wall system;

d) At mid-height adjacent to a fixed edge;

e) At mid-height adjacent to a free edge;

f) At mid-width adjacent to a horizontal joint (positive pressure zone);

g) At mid-height adjacent to a vertical joint (positive pressure zone).

8.3. Deformation measurements

The zero for the test shall be the deflection and axial deformation measured after the load is applied at the start of the test prior to heating and after deformation has stabilized.

For single wall specimens, the axial vertical deformations shall be measured. For double-wall specimens, the axial vertical deformations of the loaded leaves shall be measured independently.

Measurements of the horizontal deformations shall be made on the unexposed face in a sufficient number of positions to establish the maximum displacement.

9. Test procedure

9.1. Application of load

The application and verification of the load for the vertical element shall be in accordance with TCVN 9311-1:2012 and 6.3 of this standard.

9.2. Furnace control

Measurements and control of conditions such as furnace temperature and pressure shall be in accordance with TCVN 9311-1:2012.

9.3. Measurements and observations

Monitoring of the specimen against the criteria of loadbearing capacity, integrity, and insulation shall involve measurements and observations in accordance with TCVN 9311-1:2012.

10. Performance criteria

The fire resistance of loadbearing vertical separating elements shall be assessed against and expressed in terms of the loadbearing capacity, integrity and insulation criteria specified in TCVN 9311-1:2012.

11. Validity of test results

The test shall be considered valid when the procedures have been conducted within the limits specified as appropriate to the requirements of: the test equipment, test conditions, preparation of the test specimen, installation of instrumentation and test procedure, and shall be in compliance with the requirements of this standard.

The test shall also be considered valid when the fire exposure conditions relating to furnace temperatures, pressures and the pre-test ambient temperature exceed the limits of the tolerances specified in this standard and TCVN 9311-1:2012.

12. Expression of test results

The results of the fire resistance test shall be expressed in accordance with TCVN 9311-1:2012.

When a test is conducted on a specimen loaded to an engineering load specified by the test sponsor to be less than the maximum that could occur according to an accepted code of practice, the loadbearing capacity shall be expressed in the test result with the term “limited”. The details of this loading discrepancy shall be stated in the test report.

13. Test report

The test report shall be in accordance with TCVN 9311-1:2012.

ANNEX A (Informative) FIELD OF DIRECT APPLICATION OF TEST RESULTS

The results of a fire resistance test may be directly applied to similar unloaded vertical elements not subject to testing provided that each of the following is true:

a) The height is not increased;

b) The load is not increased, the eccentricity is not increased, and the load position is unchanged;

c) The boundary conditions are unchanged;

d) The thickness is not reduced;

e) The characteristic strength and density of any materials are unchanged;

f) The insulation is not reduced at any location;

g) There is no change in the cross-sectional design (e.g. the position of reinforcement);

h) The dimensions of any apertures are not increased;

i) The method of protection of any apertures is unchanged (e.g. glazing, doorsets, penetration sealing systems);

j) The position of any apertures is unchanged;

k) The length is not increased when the test specimen was tested restrained on its vertical edges.

[1] TCVN standards to be issued