What kind of sand can be washed？

What kind of sand can be washed？

Construction sand has a wide range of uses. Sand is one of the main components of concrete and mortar, and it is the bulk material of civil engineering. Sand is generally divided into natural sand and artificial sand. It is formed by natural conditions, mainly by rock weathering, and the particle size is less than 5mm, which is called natural sand. Artificial sand, namely machine-made sand and sand washing machine, refers to the rock particles which are broken by machinery after soil removal The size of rock particles made by crushing and sieving is less than 4.75mm, but it does not contain the particles of soft rock and weathered rock. The specifications of sand can be divided into coarse, medium and fine according to the fineness modulus (the index of coarseness and classification of natural sand particle size).
   coarse sand: the fineness modulus is 3.7-3.1, and the average particle size is more than 0.5mm.
   medium sand: fineness modulus is 3.0-2.3, average particle size is 0.5-0.35mm.
   fine sand: the fineness is 2.2-1.6, and the average particle size is 0.35-0.25mm.
   extra fine sand: fineness modulus is 1.5-0.7, average particle size is less than 0.25mm.
The larger the     fineness modulus is, the coarser the sand is. The fineness modulus of sand for ordinary concrete is in the range of 3.7-1.6, which is suitable for medium sand, or coarse sand plus a small amount of fine sand, with the ratio of 4:1.
The grain gradation of sand refers to the matching proportion of sand size particles. If the sand is of the same thickness and fineness, the gap is large. When two kinds of sand are combined, the gap is reduced. When three kinds of sand are combined, the gap is smaller. It can be seen that the porosity of sand depends on the matching degree of sand particle sizes at all levels. A good sand can not only save cement, but also improve the quality of concrete and sand Density and strength of slurry