River sand is an order of magnitude higher than sand mined in a career. The fact is that such sand is cleaned from crushed stone directly in the career and gets rid of other extraneous substances. Career sand may contain clay, which does not allow the composition to sag. There are also crushed stone stones. The most in demand today is sand and gravel. It is ideal for the manufacture of concrete, residential buildings, roads. They are performed by high -quality reinforced concrete products.