GB/T 8813-2020Rigid cellular plastics--Determination of compression properties (English PDF)

Foreword

This Standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This Standard replaces GB/T 8813-2008, "Rigid cellular plastics -

Determination of compression properties". Compared with GB/T 8813-2008,

the major changes of this Standard are as follows:

-- Modify the scope (see Chapter 1, Chapter 1 of version 2008);

-- Modify symbols and abbreviations (see Chapter 4; Chapter 4 of version

2008);

-- Modify the displacement measurement (see 6.2.1; 6.2.1 of version 2008);

-- Modify the state adjustment (see 7.4; 7.4 of version 2008);

-- Modify the test procedures (see Chapter 8; Chapter 8 of version 2008);

-- Modify the overview (see 9.1; 9.1 of version 2008);

-- Modify the units of compressive strength and compressive stress at 10%

relative deformation (see 9.2.1, 9.3; 9.2.1, 9.3 of version 2008);

-- Modify the compressive modulus of elasticity (see 9.4; 9.4 of version 2008);

-- Modify the test report (see Chapter 11, Chapter 11 of version 2008);

This Standard uses the translation method that is equivalent to ISO 844:2014,

"Rigid cellular plastics - Determination of compression properties".

The documents of our country that have a consistent correspondence with the

international documents that are referenced in this Standard are as follows:

-- GB/T 6342-1996, Cellular plastics and rubbers - Determination of linear

dimensions (ISO 1923:1981, IDT).

This Standard was proposed by China National Light Industry Council.

This Standard shall be under the jurisdiction of National Technical Committee

48 on Plastic Products of Standardization Administration of China (SAC/TC 48).

The drafting organizations of this Standard: Light Industry Plastics Processing

Application Research Institute, Hebei Wuzhou Kaiyuan Environmental

Protection New Material Co., Ltd., Wuhan Industrial Control Inspection and

Testing Co., Ltd., Shanghai Pugong Testing Technology Co., Ltd., China

National Centre for Quality Supervision & Test of Plastic Products (Beijing).

Rigid cellular plastics - Determination of compression

properties

1 Scope

This Standard specifies methods for determining the following parameters:

a) Compressive strength and relative deformation; or

b) Compressive stress at 10% relative deformation; and

c) Compression modulus of rigid cellular plastics, if needed.

There are two methods:

-- Method A uses beam displacement to determine compression properties.

When it is necessary to determine the compressive stress at 10% relative

deformation, use Method A.

-- Method B uses a strain measurement device (contact extensometer) or a

similar device that is fixed on the sample to directly measure the

deformation of the sample. When it is necessary to determine the

compression modulus, use Method B.

Note: Both method A and method B can determine the compressive strength

(at maximum load).

2 Normative references

The following documents are indispensable for the application of this document.

For dated references, only the dated version applies to this document. For

undated references, the latest edition (including all amendments) applies to this

document.

ISO 1923, Cellular plastics and rubbers - Determination of linear dimensions

3 Terms and definitions

The following terms and definitions are applicable to this document.

5 Principle

Apply a vertical compressive force to the surface of the sample, so as to

calculate the maximum stress that the sample bears. If the relative deformation

corresponding to the maximum stress is less than 10%, call it "compressive

strength". If the relative deformation corresponding to the maximum stress

reaches or exceeds 10%, take the compressive stress at 10% relative

deformation as the test result, which is called "compressive stress at 10%

relative deformation".

6 Equipment

8 Test procedure

The test condition shall be the same as the condition of the sample state

adjustment.

According to the provisions of ISO 1923, measure the three-dimensional size

of each sample. Place the sample in the center between the two parallel plates

of the compression testing machine; compress the sample at a rate of 10% of

the initial thickness of the sample per minute as much as possible, until the

compressive strength sigmam and/or the compressive stress at 10% relative

deformation sigma10 are measured.

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