GB/T 14685-2022Pebble and crushed stone for construction (English PDF)

3.2 Crushed stone Rock particles, which have a particle size greater than

4.75 mm, as produced from natural rocks, pebbles or mining waste rocks, through mechanical processing such as crushing and screening.

3.4 Irregular particle The particles of pebbles and crushed stone whose smallest one-dimensional size is less than

0.5 times the average particle diameter of the particle level to which the particle belongs.

3.5 Clay content in pebble The content of clay particles in pebbles, which have a particle size less than 75 µm.

3.6 Clay content and fine content in crushed stone The content of clay and stone powder particles in the crushed stone, which have a particle size less than 75 µm.

6.3 Elongated and flaky particle content and irregular particle content

6.3.1 Elongated and flaky particle content The elongated and flaky particle content of pebbles and crushed stone shall comply with the requirements in Table 3.

6.3.2 Irregular particle content The irregular particle content of category I pebbles and crushed stone shall not exceed 10%.

6.4 Hazardous substances The harmful substance content of pebbles and crushed stone shall comply with the provisions of Table 4.

6.5 Soundness When using the sodium sulfate solution method for testing, the mass loss of pebbles and crushed stone shall comply with the requirements in Table 5.

6.6 Strength

6.7 Apparent density, continuous graded loose packing void ratio The apparent density of pebbles and crushed stone and the void ratio of continuously graded loose stacks shall comply with the following requirements.

6.8 Water absorption rate The water absorption rate of pebbles and crushed stone shall comply with the requirements in Table 9.

6.9 Radioactivity The radioactivity of pebbles and crushed stone shall comply with the requirements of GB 6566.

6.10 Alkali-aggregate reaction When the purchaser makes a request, the measured expansion rate and alkali activity evaluation results shall be provided.

6.11 Moisture content and bulk density When the purchaser makes a request, the actual measured value shall be provided.

7.3 Particle gradation

7.3.1 Instruments and equipment Instruments and equipment shall meet the following requirements.

7.6 Elongated or flaky particle content

7.6.1 Instruments and equipment Instruments and equipment shall meet the following requirements.

7.6.2 Test procedures

7.6.3 Result calculation and evaluation The content of elongated or flaky particles shall be calculated according to formula (3), accurate to 1%.

7.7 Irregular particle content

7.7.1 Instruments and equipment Instruments and equipment shall meet the following requirements.

7.8 Organic matter content

7.8.1 Reagents and materials Reagents and materials shall comply with the following requirements.

7.8.2 Instruments and equipment Instruments and equipment shall meet the following requirements.

7.10 Soundness

7.10.1 Reagents and materials Reagents and materials shall comply with the following requirements.

7.10.2 Instruments and equipment Instruments and equipment shall comply with the following requirements.

7.12 Crush Indicator

7.12.1 Instruments and equipment Instruments and equipment shall meet the following requirements.

7.14 Packing density and void ratio

7.14.1 Instruments and equipment Instruments and equipment shall meet the following requirements.

7.14.3 Result calculation and evaluation

7.14.4 Calibration method of volumetric cylinder Fill the volumetric cylinder with drinking water, at a temperature of 15 °C ~ 25 °C. Use a glass plate to push it along the opening of the cylinder, to make it close to the water surface. Wipe the outer wall of the cylinder dry. Then weigh its mass. The volume of the volumetric cylinder is calculated according to formula (17), accurate to 1 mL.

7.15 Water absorption

7.15.1 Instruments and equipment Instruments and equipment shall meet the following requirements.

7.15.3 Result calculation and evaluation

7.16 Radioactivity It is carried out, according to the provisions of GB 6566.

7.18 Moisture content

7.18.1 Instruments and equipment Instruments and equipment shall meet the following requirements.

8.1 Inspection

8.1.1 Exit-factory inspection The exit-factory inspection items of pebbles and crushed stone shall be. loose packing density, particle gradation, clay content in pebble (clay content and fine content in crushed stone), clay lumps and friable particles content, elongated or flaky particle content, irregular particle content (category I).

8.1.2 Type inspection Type inspection shall be carried out under any of the following circumstances.

8.2 Group-batching rules Group batches according to the same classification, category, nominal particle size, daily output. If the daily output does not exceed 4000 t, every 2000 t forms a batch; if it is less than 2000 t, it is also a batch.

8.3 Determination rules

8.3.1 When the test results are all in compliance with the provisions of 6.1 ~

6.9 of this document, the batch of products can be judged to be qualified.

8.3.2 When a test result does not meet the requirements of 6.1 ~ 6.9, it shall double the sample from the same batch of products, to carry out reinspection of this item. After re- inspection, if the test results meet the requirements, the batch of products can be judged to be qualified; if they still do not meet the requirements of 6.1 ~ 6.9, they will be judged to be unqualified. When two or more test results are inconsistent, the batch of products will be deemed unqualified.