River sand price skyrocketed, mechanism sand "popular", you do not understand can not
Recently, mechanism sand price rises all the way, in the past to gravel processing mainly manufacturers have also joined the ranks of mechanism sand, but before "into line" you still need to make clear these knowledge points!
1. What is mechanism sand?
According to the provisions of "construction sand" (GB/ t14684-2011) : rock, mine tailings or industrial waste slag particles with particle size less than 4.7mm made by mechanical crushing and screening after soil removal treatment, but excluding soft and weathered particles.
Extra-fine sand: natural river sand with fineness modulus of 0.7-1.5 obtained by testing according to the method specified in "construction sand" (GB/T14684).
Mixed sand: sand made by mixing mechanical sand with natural sand.
2. What is machine-made sand concrete?
Concrete prepared with mechanical sand as fine aggregate. At present, the annual production of mechanism sand in foreign countries is no less than 5 billion tons.
3. What kind of mechanical sand is qualified?
Mechanical sand that meets the national technical standards and has passed the factory inspection is qualified. Generally need to detect the items are: fineness modulus, particle size, stone powder content, apparent density, voidage, crushing value, methylene blue MB value.
4. Which rocks can be used for mechanical sand production?
Mechanism sand (gravel) sand-making raw materials are usually granite, basalt, river pebbles, pebbles, andesite, rhyolite, diabase, di