This standard specifies the test method for tensile properties of glass fiber reinforced cement. This standard is applicable to the determination of tensile properties of alkali-resistant glass fiber reinforced cement paste or mortar (GRC for short). GB/T 15231.4-1994 Test method for properties of glass fiber reinforced cement Tensile properties GB/T15231.4-1994 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Test methods for the properties of glass fiber reinforced cementTensile properties
Test methods for the properties of glass fiber reinforced cementThe properties of direct tension1 Subject content and scope of application
This standard specifies the test method for tensile properties of glass fiber reinforced cement. GB/T15231.4-94
This standard is applicable to the determination of tensile properties of alkali-resistant glass fiber reinforced cement paste or mortar (abbreviated as GRC). 2 Instruments
2.1 Electronic universal testing machine: range 50kN, accuracy 1%. 2.2 Vernier caliper: reading value 0.02mm.
3 Test piece
3.1 The test piece is 250mm long, 30mm wide and 8mm thick. For tensile tests for the purpose of inspecting product quality, if the test piece cannot be cut from the product according to the specified thickness, its minimum thickness shall not be less than 6mm. If it exceeds 10mm, it must be ground to 10mm before use. 3.2 The length of the test piece is 180mm, and the ratio of the length to the width is 6. For the tensile test for the purpose of inspecting the quality of the product, when the test piece cannot be cut out from the product according to the specified size, the ratio of the length to the width of the test piece can be 5-7. 3.3 According to the provisions of 3.1 and 3.2, the test pieces are cut from the middle of the test plate of 600mm×600mm×10mm or the middle of the product, and each group has 6 pieces. 3.4 The test piece is fully moistened and cured for 26 days at a temperature of 20±3℃ and a relative humidity of more than 80%, and then placed in a well-ventilated room for 48 hours to make it in an air-dried state before testing. 3.5 The surface of the test piece should be flat and the two sides should be parallel. Otherwise, it needs to be ground before use. 4 Test conditions
The test should be carried out in a room at 205C.
5 Test steps
5.1 Measure the width and thickness of the test piece in the center of the test piece with an accuracy of 0.25mm. 5.2 As shown in Figure 1, first clamp the specimen in the upper wedge-shaped chuck, and insert a 0.8mm thick aluminum sheet between the chuck and the specimen. The chuck is flexibly connected to the loading device. Then separate the clamping pieces of the lower wedge-shaped chuck, and clamp the other end of the specimen in the lower wedge-shaped chuck padded with a 0.8mm thick aluminum sheet. The specimen must be accurately centered and clamped along the width and thickness directions. 5.3 Paste the resistance strain gauge in the center of the specimen and arrange it symmetrically on both sides of the specimen. 5.4 Apply load at a loading speed of 1~~2mm/min until the specimen breaks, and draw the load-strain curve with a function recorder. Approved by the State Administration of Technical Supervision on September 24, 1994 420
Implementation on June 1, 1995bzxZ.net
6 Result calculation and evaluation
6.1 Obtain the following values ​​from the load-strain curve: GB/T 15231.4-94
Tensile proportional limit load (i.e. the load when the curve just starts to leave the straight line) W,; Maximum tensile load W2;
One-third of the tensile proportional limit load W:,
Strain at W. .
6.2 Calculate the tensile proportional limit strength according to formula (1): BOP =
W: BOP
Tensile proportional limit strength, MPa;
Tensile proportional limit load, kN;
Specimen width, mm;
dSpecimen thickness, mm.
6.3 Calculate the tensile strength according to formula (2):
tt: urs-
-tensile strength, MPa;
W-maximum tensile load, kN;
b-specimen width, mm.
d-specimen thickness, mm.
× 103
Lower die chuck; 2 Aluminum sheet 3 Test piece; 4 Upper die chuck; .--Strain gauge (1)
6.4 Calculate the tensile elastic modulus according to formula (3): Tensile elastic modulus.MPa;
t: E. --.
GB/T 15231. 4 - 94
w… tensile proportional limit load, kN; test piece width, mm;
d test piece thickness, mm
Strain at E·W.
× 103
5 The result is expressed as the average value of 6 test pieces, accurate to 0.1MPa. 6.5
Test report
The test report must include the following contents:
Type, size, age and curing conditions of the test piece; average value of tensile ultimate strength (BOP); average value of tensile strength (UTS);
average value of tensile elastic modulus (E,);
Test period, unit and personnel.
Additional remarks:
This standard was proposed by the State Administration of Building Materials Industry. This standard was drafted by the Building Materials and Concrete Research Institute of the China Academy of Building Materials Science. The main drafters of this standard are Shen Rongxi and Yang Ruishan122
(3)
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