GB/T 9966.13-2021Test methods for natural stone—Part 13: Determination of water absorption coefficient by capillarity (English PDF)

Foreword

GB/T 9966 "Test Methods for Natural Stone" consists of 18 parts.

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

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

Part 3: Water absorption, bulk density, true density, and true porosity tests;

Part 4: Abrasion Resistance Test;

Part 5: Hardness Test;

Part 6: Acid Resistance Test;

Part 7: Strength Test of Stone Hanging Component Assembly Unit;

Part 8: Test Method for Structural Strength Testing of Stone Hanging Systems Using Uniform Static Pressure Difference;

Part 9: Determination of dynamic elastic modulus by measuring the fundamental resonant frequency;

Part 10: Determination of the seismic performance of the hanger assembly unit;

Part 11: Determination of Accelerated Aging Strength Due to Rapid Cooling and Heating;

Part 12: Determination of Static Modulus of Elasticity;

Part 13: Determination of capillary water absorption coefficient;

Part 14: Determination of fracture resistance energy;

Part 15: Determination of Salt Spray Aging Resistance;

Part 16: Determination of the linear thermal expansion coefficient;

Part 17: Determination of Salt Crystallization Strength;

Part 18: Lithofacies Analysis.

This part is Part 13 of GB/T 9966.

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

1 Scope

This part of GB/T 9966 specifies the principle, instruments, equipment, sample preparation, and test procedures for the capillary water absorption coefficient test of natural stone. Test results and test report.

This section applies to the determination of the capillary water absorption coefficient of natural stone.

4 Principles

After the sample is dried to constant weight, one side (the untreated side) is immersed in water to a depth of (3±1) mm below the surface, and measurements are taken within a specified time period. The mass increase is calculated by determining the capillary water absorption coefficient, which is the amount of water absorbed per unit area over time.

5 Instruments and Equipment

5.1 Flat-bottomed water tank with lid. built-in non-oxidizing, non-absorbent sample holder.

5.2 Water level control device. maintains a constant water level in the tank.

5.3 Timer. Accurate to 1 second.

5.4 Blower drying oven. can maintain the temperature at (65±5)°C.

5.5 Balance. accurate to 0.01 g.

5.6 Vernier calipers or other length measuring tools. The measuring accuracy shall not be less than 0.1 mm.

5.7 Temperature control equipment. Maintain the room temperature at (20±5)°C.

5.8 Dryer.

6 Sample Preparation

7 Experimental Procedure

7.1 Measure the mass (ma) of each dried sample, accurate to 0.01 g.

7.2 Measure the length of the two midlines of the immersed surface of each sample, accurate to 0.1 mm, and calculate the immersed area (A) of the sample, in square meters. express.

7.3 Place the sample on the support in the water tank, ensuring that only a very small area of the bottom of the sample is on the support, and that the rise is related to the water level. The position of the anisotropic surface is consistent with the requirements.

7.4 Add deionized water or distilled water to the water tank, immerse the bottom of the sample to (3±1) mm below the water surface, and start timing.

7.5 Close the water tank lid to prevent moisture from evaporating from the wetted sample. To maintain the water level, add water as needed during the test.

7.6 Different soaking times should be selected for each type of stone according to its water absorption rate. The water absorption rate test should be performed according to GB/T 9966.3. Marble, granite, slate, etc., soaked in 0.6% water for 1440 minutes; marble, limestone, etc., with a water absorption rate greater than 0.6% but not greater than 1.0% Soak limestone, sandstone, and other stone materials with a water absorption rate greater than 1.0% for 480 min. Record the data from the start of the test to each weighing. Time (t), accurate to 1 s.

7.7 When weighing, remove the sample, carefully remove any water droplets from the wetted portion with a wrung-out damp cloth, and immediately measure the mass (m); accurately. Up to 0.01g.

8 Test Results

8.1 The capillary water absorption coefficient is described as the mass of adsorbed water divided by the square root of the area immersed in water and the time. The capillary absorption coefficient for each sample... The water coefficient is calculated according to formula (1).

8.2 The arithmetic mean of each group of samples shall be used as the test result, and the result shall be retained to three significant figures.

9 Test Report

The test report should include at least the following information.

a) The commercial name of the stone as specified in GB/T 17670;

b) Sample quantity, dimensions, surface treatment (as required for testing), and orientation of anisotropic surfaces;

c) Dates of sample delivery, preparation, and measurement;

d) The name and address of the testing laboratory; if the test is not conducted in a testing laboratory, the location of the test should be noted.

f) The capillary water absorption coefficient (C1 or C2) of each sample perpendicular to or parallel to the anisotropic surface;

h) Test deviations (such as specimen size and surface treatment).