Test method: clean with 75 micron sieve.
The new national standard GB14684-2001and the national standard GB14685-2001for building pebbles and broken stones were approved by the General Administration of Technical Quality Supervision and Quarantine and released on July 6, 2006. ?
People's Republic of China (PRC) National Standard "Building Sand" (Abstract)
1 and range
This standard specifies the definition, classification and specifications, technical requirements, test methods, inspection rules, marks, storage and transportation of building sand.
This standard is applicable to sand and building mortar for concrete and its products in building engineering.
2. Cite GB14684-2001for building sand and GB14685-2001for building pebbles and gravels.
The clauses contained in the following standards constitute the clauses of this standard by reference in this standard. At the time of publication of this standard, all versions shown are valid. All standards will be revised, and all parties using this standard should explore the possibility of using the latest version of the following standards.
GB 175- 1999 portland cement and ordinary portland cement.
3. The following definitions are adopted in this standard.
3. 1. Natural sand
Rock particles with particle size less than 4.75 mm formed by natural weathering, water flow handling and sorting, and accumulation, but excluding particles of soft rock and weathered rock.
3.2, artificial sand (artificial sand)
Machine-made sand and mixed sand after soil removal are collectively referred to.
Machine-made sand: rock particles with particle size less than 4.75 mm, which are formed by mechanical crushing and screening, but do not include particles of soft rock and weathered rock.
Mixed sand: sand mixed by machine-made sand and natural sand.
3.3. Mud content (material of natural sand less than 75 μ min)
Content of particles with particle size less than 75μm in natural sand.
3.4. Stone powder content (machine-made sand with material particle size less than 75 μm)
Content of particles with particle size less than 75μm in artificial sand.
3.5, clay content (clay)
The original particle size of sand is greater than 1. 18mm, and the particle content is less than 600μm after washing and kneading.
3.6. Fine module
An index to measure the thickness of sand.
3.7. Health
The ability of sand to resist cracking under natural weathering and other external physical and chemical factors.
3.8. Light substances (substances lighter than 2000 kg/m3)
A substance with an apparent density of less than 2000 kg/m3.
3.9. Alkali Aggregation Reaction
It refers to the expansion reaction of concrete components such as cement and admixture with alkali in the environment and alkali-active minerals in aggregate, which occurs slowly in wet environment, leading to concrete cracking and destruction.
3. 10, methylene blue MB value (methylenebluevalue)
An index used to determine whether the content of particles with a particle size less than 75μm in artificial sand is mainly soil or stone powder with the same chemical composition as the treated parent rock.
4. Classification and specifications
4. 1, classification
Sand is divided into natural sand and artificial sand according to production sources:
Natural sand: including river sand, lake sand, mountain sand and desalinated sea sand;
Artificial sand: including machine-made sand and mixed sand.
4.2, specifications
Sand is divided into coarse, medium and fine specifications according to fineness modulus, and its fineness modulus is as follows:
Rough: 3.7-3. 1
English: 3.0-2.3
Fines: 2.2- 1.6
4.3.types
According to the technical requirements, sand can be divided into Grade I, Grade II and Grade III.
4.4. Use
Grade I is suitable for concrete with strength grade greater than C60; Class II is suitable for concrete with C30-C60 strength grade, frost resistance, impermeability or other requirements; Grade III is suitable for concrete and building mortar with strength grade less than C30.
5. Technical requirements
5. 1, particle gradation
Grain gradation of sand shall conform to the provisions of Table 1.
Table 1 particle gradation
Note ①: Compared with the figures listed in the table, except for 4.75mm and 600μm screens, the actual particle size distribution of sand may slightly exceed the standard, but the total amount of exceeding the standard should be less than 5%.
②: The cumulative surplus of artificial sand 150μm sieve holes in185, artificial sand 150μm sieve holes in Area 2/0/80, and artificial sand13.