Sand-gravel mixture (ASG) – an inorganic granular bulk construction material mined in open pits, from the date of rivers, lakes and seas. cbc is used to align the construction site, the device of road surfaces the top layer of ground under the cover, forming drainage layer. Also, sand and gravel used to backfill pits, trenches in the residential and commercial construction, laying and repairing communications. Most widely-rich sand and gravel opgs (derived from natural sand and gravel through the enrichment), which contains 70% gravel and 30% sand, allowing the mixture does not succumb to the strong shrinking at a fairly high load. Such opgs can be used for primary stable layer before pouring the concrete playgrounds, roads or, for example, before installing the tennis court.
asg is divided into natural and enriched with sand-gravel mixtures: natural – for construction of road surfaces, the top layer of ground under the coating layer for drainage and for other purposes in road construction in accordance with the requirements of rules and regulations for the construction of highways; enriched (derived from natural sand and gravel through the fortification) – in accordance with the requirements of building regulations to include appropriate construction works. Standard does not apply to natural sand-gravel mixture (ASG), used as a semifinished product for the downstream consumers. Specifications for Sand and gravel (CBC) is characterized by: the content of gravel and sand mixture, the highest grain size of gravel; indicators adopted for the evaluation of gravel in accordance with gost 8267-93 (grain composition, strength and content of the grains of soft rock, frost, content of dust, clay and silt particles, clay lumps, and mineralogical and petrographic composition); indicators adopted for the evaluation of sand in accordance with gost 8736-93 * (grain composition and gradation, dust content, clay and silt particles, including clay lumps, organic impurities, and mineralogical and petrographic composition).