The concrete of high specific weight is prepared, using crushed stone as filler. There are several types of this stone: granite, calcareous, gravel, secondary. Depending on requirements to durability of concrete choose any given type of filler.
Instruction
1. For preparation of the concrete having high strength use heavy aggregates, one of which is crushed stone. These stones are distinguished in several parameters: size, resistance to influence of temperature, radioactivity, durability, leshchadnost. Depending on way of production and type of rock, crushed stone is granite, calcareous, gravel, secondary. Granite stones have the most high strength. This filler of the most expensive therefore it is used only for preparation of high-quality concrete: M350 brands above.
2. For construction of owner-occupied dwelling gravel or secondary crushed stone of average fraction (20/40 mm) will be the best choice. The houses built by individual builders generally have small weight. Therefore the foundation load is not so big. Necessary bearing capacity to it will be quite provided by M200 brand concrete. For its preparation as filler use gravel crushed stone.
3. If stones are received by crushing of dolomitic breeds (and it is generally limestone), it is necessary to consider that they have hygroscopicity. Therefore to define water cement ratio in concrete with calcareous crushed stone quite difficult. It is important point because concrete durability depends on this parameter. If in solution there is few liquid, then in monolith there will be cracks and emptiness. It considerably will reduce bearing capacity of the base.
4. The best crushed stone - that which form is close to cubic. Therefore, in the choice it is necessary to consider leshchadnost of stones. The cement consumption in many respects depends on this parameter. Therefore those private developers who seek to save first of all should pay attention to form of stones. In addition, cubic filler considerably will increase the concrete durability as keeps within in solution more densely. Therefore, there is one more opportunity to save: the base from high-strength concrete can be not so massive.
5. In the choice of crushed stone the size of stones is important. Usually for construction of foundation of the house it is enough to stop on average fraction. But for regions with low temperatures it is required to consider also degree of frost resistance. In this case F300 brand crushed stone will be the optimum choice. Digits indicate here quantity of cycles of freezing defrosting which the stone will be able to sustain without prejudice to the durability.