GB/T 9966.3-2020Test methods for natural stone - Part 3:Determination of water absorption,bulk density,true density and true porosity (English PDF)

3.1 true density

value reflecting the true density of rock not considering the influence of open pores and closed pores contained in stone

3.2 true porosity

volume percentage of closed pores contained in stone

4.1 Air drying oven

the temperature may be controlled at 65°C± 5°C.

4.2 Balance

with the accuracy of 10mg for the maximum weighing of 1,000g;with the accuracy of 1mg for the maximum weighing of 2,000g.

4.3 Water tank

the bottom surface is flat, with glass rods as specimen support.

4.4 Metal basket

it can meet the requirements of specimens of various specifications and has sufficient rigidity.

4.5 Pycnometer

the volume is 25mL-30mL.

4.6 Standard sieve

63µm.

4.7

Dryer.

5.1 Water absorption and bulk density

5.1.1

The specimen is a cube with a side length of 50mm or a cylinder with a diameter and height of 50mm, and the size deviation is ±0.5mm, with five pieces in each group. Other specimens with regular shapes may be selected if any special requirements. The geometric volume of the specimen shall not be less than 60cm3, and the ratio of surface area to volume shall be in the range of 0.08mm-1 - 0.20mm-1.

5.1.2

The specimens shall be taken from representative parts, without cracks and other defects.

5.1.3

The surface of the specimen shall be smooth, and the rough surface shall be polished.

5.2 True density and true porosity

Take about 1,000g of clean sample and crush it into particles less than 5mm; divide by quartering, take a powder sample that has been ground to pass the 63µm of standard sieve, and take 150g as the specimen.