Artificial river sand

River sand is generally divided into two types: artificial river sand and natural river sand. Artificial river sand, known as machine-made sand, is a rock particle with particle size less than 4.75mm separated and broken by crushing machine after removing soil. But it does not contain soft rock and particles of weathered rock. Rock particles formed under natural conditions (mainly rock weathering) and below 5mm diameter are called natural river sands.
The size of sand is divided into three types: coarse, medium and fine according to the fineness modulus (the index of the thickness and type of the natural sand diameter).
Coarse sand: fineness modulus is 3.7 - 3.1, and the average particle size is o.5mm or more.
Medium sand: fineness modulus is 3 - 2.3, and the average particle size is O.5 - 0.35mm.
Fine sand: fineness template is 2.2 - 1.6, and the average particle size is 0.35 - 0.25mm.
Super fine sand: fineness modulus is 1.5 o.7, and the average particle size is below o.25mm.
The greater the modulus of the fineness, the thicker the sand. The fine modulus of sand for ordinary concrete is 3.7-1.6, medium sand is suitable, or coarse sand plus a small amount of fine sand is 4:1. The particle gradation of sand refers to the proportion of the size and size of the sand. If the same thickness of sand, the largest gap, the size of the two kinds of sand mix together, the gap is reduced, the three kinds of particle size sand match, the gap is smaller. It can be seen that the voidage of sand depends on the degree of collocation of sand grains at all levels. The well graded sand can not only save cement, but also improve the density and strength of concrete and mortar.
The specifications of artificial river sand are 4-8 mesh, 8-16 mesh, 16-30 mesh, 30-60 mesh, 40-70 mesh, 50-100 mesh, etc.
Artificial river sand is a natural stone, which is produced by repeated collisions and frictions through the force of water for a long time. Its composition is more complex, the surface has a certain smoothness, and the content of impurities is more. The cement paste forms strong adhesive force, which enhances the bending strength and compressive strength of the slurry, and is beneficial to the improvement of the overall strength of the polystyrene granule insulation slurry.