Sand making machine – what are the requirements for sand aggregate?

Cobblestone sand making machine, also known as high-efficiency sand making machine, is a special sand making equipment for construction production sand. Because the sand and gravel produced are more uniform in particle size and have strong compression and wear resistance. Compared with natural sand, the cobblestone sand making machine produces. The sand is more in line with the high standard construction sand requirements.

Sand making machine – Sand and gravel is one of the main components of concrete, which is customarily called aggregate or aggregate. Those with a particle size above 4.75ram are called stones, and those below 4.75ram are called sand.

Ordinary sand refers to rock particles with a particle size below 4.75mm formed under natural conditions, including river sand, sea sand and mountain sand.

Characteristics of ordinary sand

(1) Harmful impurity content: Sand often contains impurities such as clay, silt, organic matter, mica, sulfide and sulfate.

(2) Thickness and particle gradation: The sand used for mixing concrete should not be too coarse or too fine. The particle gradation of sand is the combination of large, medium and small particles in the sand. The thickness and particle gradation of the sand are determined by sieve analysis. The thickness of the sand is expressed by the fineness modulus Mx. The sand can be divided into three specifications: coarse, medium and fine according to the fineness modulus Mx: 3.7-3.1 is coarse sand, 3.0-2.3 is medium sand, and 2.2-1.6 is fine. sand. Ordinary concrete sand is preferably medium sand.

(3) Physical properties of sand: the apparent density is generally 2.55-2.759/cm3; the bulk density of dry sand is generally 1450-1700kg/m3. The moisture state of sand is divided into four states: fully dry, air-dry, surface-dry and wet. The standard stipulates that the design mix ratio of the aggregate is in the dry state. And the moisture content in other states should be converted.