In modern construction, a large number of natural non-metallic materials and their mixtures are used. In most cases, it is sand, gravel, clay. At the bottom of reservoirs, rivers and seas, a mixture of sand and gravel is mined, which is the basis of OPGS. What is it and what is the difference between ASG and OCG?
Mixtures of natural materials
Sand and gravel mixtures are very popular and are part of concrete structures that are used in the construction of houses, paving roads, laying the foundation. The quality of the mixtures and their properties depend on where they were mined. The main indicator is bonding properties. Often require mixtures in which the amount of gravel is increased. To do this, gravel is added to the natural mixture. Used specifically designed for this equipment - vibration screen. The result is a mixture of OPGS, the decoding of which is an enriched sand-gravel mixture. The artificially enriched mixture is part of concrete: it is combined with cement and water. The main thing is compliance with the proportions so that the concrete is of the right quality for the purpose for which it is intended. The scope of concrete depends on the quantity and quality of gravel. The natural mixture of ASG contains up to 20% of gravel, and when enriched, its amount is increased to 75%, as can be seen in the photo. OPGS and refers to the artificially enriched composition of ASG.
The composition and division of the OCG into groups
Of great importance is the size of the crushing of grains, the presence of clay and silt in the composition of the mixture. All this affects such an indicator as the strength of the OPGS. What is it: concrete quality indicators ? This is not only strength, but also frost resistance.
One of the most popular OPGS is considered a mixture in which the gravel content is 70%. The remaining 30% is sand, which is free from impurities. But the composition of the mixture may contain clay, not more than 1% of the total mass, and up to five percent of organic substances. Gravel grains come in different sizes: from 10 to 70 mm. It should not be a mix. The mixture uses grains of one of the fractions: their size can be either 10, or 40, 20 or 70 mm. OPGS is divided into groups according to the content of gravel in them as a percentage:
- up to 25%;
- from 25 to 35%;
- from 35 to 50%;
- from 50 to 65%;
- up to 75%.
Mode of application
Just as it is divided into OPGS groups (what it is - they have already been decoded), so concrete is produced of different types. It all depends on where and why it is used. Standard method of preparation: four parts of the mixture are taken, one is cement and ½ part of water. Part of the ingredients is determined by weight. When concrete is being prepared for laying the foundation, the optimal ratio of parts is 1: 8. Given the amount of gravel in the composition, the type of cement that is taken to prepare the mixture, receive the concrete of the brand that is required. In road construction from OPGS make some layers in the base or top pavement. In the construction of houses, concrete is used not only for the foundation, but also for cement screeds, for concreting floors. On the territory around the building, landscape design is also done using concrete and a mixture of OPGS.
Mix Features
As a building material, the mixture is very convenient and has great popularity in construction work. After all, it perfectly levels the surface. This quality is especially useful when paving roads. When buying an enriched sand-gravel mixture for construction, you should pay attention to some of its parameters: the group to which it belongs, what is the percentage of the content of clay, dust, silt in it. All these indicators affect the cost of OCG. What is it and how to find out the percentage of all inclusions? It should not exceed 3% of the total mass. It is worth paying attention to what fractions gravel has: they should not exceed 40 mm. All information is indicated in the documents confirming the compliance of the mixture with the requirements of GOST.