GB/T 17669.3-1999 Gypsum plasters -Determination of mechanical properties
1 Scope
This standard specifies methods for determining flexural strength, compressive strength and hardness of gypsum plasters.
This standard is applicable to gypsum plasters requiring for their use only the addition of water.
2 Normative references
The following standards contain provision which, through reference in this standard, constitute provisions of this standard. At the time of publication, all editions listed were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below.
GB/T 17669.1-1999 General test conditions for gypsum plasters
GB/T 17669.4-1999 Gypsum plasters - Determination of physical properties of pure paste
JC/T 724-1982 (1996) Apparatus for physical test of cement Electrically driven flexure testing device
JC/T 725-1982 (1996) Apparatus for physical test of cement Compression jig
JC/T 726-1982 (1996) Apparatus for physical test of cement Mould for cement mortars
3 Test conditions
Test conditions shall meet those specified in GB/T 17669.1.
4 Test pieces
4.1 Sample treatment
Process the powder sample according to the requirements of GB/T 17669.1.
4.2 Apparatus for test pieces
4.2.1 Electronic scale with a sensitivity of 1g.
4.2.2 Molding die shall meet the requirements of JC/T 726.
4.2.3 Mixing container shall meet the requirements of GB/T 17669.1.
4.2.4 Mixing spatula consists of three oval rings bent from stainless steel wires, with a wire diameter of φ1 to φ2 mm and a ring length of approximately 100mm.
4.3 Preparation of test pieces
The amount of gypsum plasters mixed and prepared in one batch shall be sufficient to fill the molds for three test pieces. The volume of paste necessary, taking losses into account, is 950mL. Using the standard consistency water consumption, the amount of gypsum plasters and water to be added can be calculated using Equations (1) and (2).
Foreword I
ISO foreword III
1 Scope
2 Normative references
3 Test conditions
4 Test pieces
5 Determination of flexural strength
6 Determination of compressive strength
7 Determination of hardness
8 Test report
