GB/T 9966.1-2020Test methods for natural stone—Part 1:Determination of dry,wet and after freezing compressive strength (English PDF)

Foreword

GB/T 9966 "Test Methods for Natural Stone" is divided into 18 parts.

--- Part 1. Compression strength test after drying, water saturation and freeze-thaw cycles;

--- Part 2. Bending strength test after drying, water saturation, freeze-thaw cycles;

--- Part 3. Water absorption, bulk density, true density, true porosity test;

--- Part 4. Wear resistance test;

--- Part 5. Hardness test;

--- Part 6. acid resistance test;

--- Part 7. Hanging strength test of stone pendant combination unit;

--- Part 8. Testing the structural strength of stone mounting systems with uniform static pressure difference;

--- Part 9. (by measuring the fundamental frequency of resonance) determine the dynamic elastic modulus;

--- Part 10. Determination of seismic performance of pendant combination units;

--- Part 11. Determination of accelerated aging intensity by chilling and heat;

--- Part 12. Determination of static elastic modulus;

--- Part 13. Determination of capillary water absorption coefficient;

--- Part 14. Determination of resistance to fracture energy;

--- Part 15. Determination of aging resistance to salt spray;

--- Part 16. Determination of the linear thermal expansion coefficient;

--- Part 17. Determination of salt crystal strength;

--- Part 18. Lithofacies analysis.

This part is the first part of GB/T 9966.

This section is drafted in accordance with the rules given in GB/T 1.1-2009.

This section replaces GB/T 9966.1-2001 "Test methods for natural facing stone. Part 1. Drying, water saturation, pressure after freeze-thaw cycles Shrinkage strength test method ". Compared with GB/T 9966.1-2001, the main technical changes in this part are as follows.

--- Added normative references (see Chapter 2);

--- Modified the sample drying temperature and constant weight time (see 3.4, 5.1.1, 2.4 and 4.1.1 of the 2001 version);

--- Added some test equipment (see 3.6, 3.7);

--- Increased the sample size and size related to the maximum particle size, adjusted the deviation, and increased the size of the large size sample (see 4.2, 2001 version 3.1);

--- Identified the marking requirements for the layering direction of the sample, and increased the number of samples required to prepare the corresponding samples when testing in accordance with the layering direction. Added schematic diagrams (see 4.3, 3.3 of the 2001 version);

--- Modified the accuracy of sample size measurement (see 5.1.2, 4.1.2 of 2001 version);

--- Modified loading rate (see 5.1.3, 2001 version 4.1.3);

--- Modified the water saturation test method steps (see 5.2.1, 4.2.1 of 2001 version);

--- Modified the freeze-thaw cycle test method of the sample (see 5.3.1 ~ 5.3.3, 4.3.1 of the 2001 version);

--- Added part of the test report (see Chapter 7, Chapter 6 of the 2001 edition).

1 Scope

This part of GB/T 9966 specifies the instruments and equipment, test samples, test procedures, and test results for the compression strength test of natural stone. Fruit and test report.

This section applies to the determination of static uniaxial compressive strength of natural stone after drying, water saturation and freeze-thaw cycles.

2 Normative references

The following documents are essential for the application of this document. For dated references, only the dated version applies to this document. For undated references, the latest version (including all amendments) applies to this document.

GB/T 17670 unified number of natural stone

3 Equipment

3.1 Testing machine. It has a spherical support and can meet the test requirements. The relative error of the displayed value does not exceed ± 1%. The failure load of the specimen shall be at the indicated value. 20% ~ 90%.

3.2 Vernier caliper. The reading value can be accurate to at least 0.1mm.

3.3 Universal Angle Ruler. Accuracy is 2 '.

3.4 Blast Dryer. The temperature can be controlled within the range of 65 °C ± 5 °C.

3.5 Freezer. The temperature can be controlled within the range of -20 °C ± 2 °C.

3.6 Constant temperature water tank. it can keep the water temperature at 20 °C ± 2 °C, the maximum water depth is 105mm, and it can hold at least 2 groups of test samples, and the bottom pad is not contaminated Cylindrical support of stone.

3.7 Dryer.

4 Test samples

4.1 Prepare samples with typical characteristics in the same batch. The samples under each test condition are a group of 5 pieces in each group.

4.2 The sample specification is usually a cube with a side length of 50mm or a cylinder of phi50mm × 50mm with a dimensional deviation of ± 1.0mm.

The largest particle size is more than 5mm, and the sample size should be a cube with a side length of 70mm or a cylinder of phi70mm × 70mm.

The difference is ± 1.0mm; if the maximum particle size in the sample exceeds 7mm, the number of each group of samples should be doubled. If dry and saturated at the same time Three groups of specimens are required for compressive strength tests after the freeze and thaw cycles.

4.3 The stratified specimen shall indicate the direction of stratification. The test is usually carried out in the direction of vertical bedding (see Figure 1).

When parallel bedding or used in load-bearing, hydraulic pressure and other occasions, choose the weakest compressive strength for testing. Parallel bedding direction should be used.

Test (see Figure 2), and a corresponding number of samples shall be prepared according to the test conditions of 4.1 and 4.2.

Note: Some stone materials have obvious bedding direction, and their splitting directions can be divided into the following three types.

a) rift direction. the direction most likely to split;