In order for the strip foundation to meet all the requirements for it, you need to be able to properly prepare concrete of a suitable grade. For monolithic foundations, this is M-200 (B15).
You will need
- - concrete mixer
- - sand
- - cement
- - gravel or crushed stone
- - sieve
- - water
Instruction manual
1
The strip foundation is the most popular among other types of substrates. This is due to its economy and excellent bearing capacity. There are two types of tapes: monolithic and prefabricated. For the construction of the former, concrete is required, for the latter, foundation blocks. A properly prepared solution is needed not only for monolithic bases, but also for prefabricated ones, since it is a binder in the laying of blocks. Therefore, the strength and durability of any strip foundation depends in many respects on the quality of the cement-sand mixture.
2
To make concrete on your own, you will need a concrete mixer. Without it, it will be difficult to process such a large volume of solution. The main ingredient of the cement-sand mixture should be cement grade M400 and above. When buying this material, you need to make sure that its expiration date has not expired. All the strength characteristics of the foundation depend on the quality of this main component of concrete.
3
According to GOST 10178-85, the shelf life of Portland cement and slag Portland cement, subject to the rules for its transportation and storage, is 45 days for quick-hardening compounds, 60 days for other types of cement, and for delivery in bulk - no more than 45 days. The buyer should be aware that in a month of storage, cement loses up to 10% of its activity. For this reason, after 6 months from the date of its manufacture, the M400 brand turns into the M300.
4
To prepare concrete on a monolithic strip foundation, sand and gravel (crushed stone) will be needed. The first should be of medium grain size and quarried. Before laying it in a concrete mixer, it must be sieved through a sieve (grate) with a mesh of 5-10 mm. Concrete aggregate is gravel or crushed stone. These stones should be of medium fraction, that is, their maximum size can be 20/40 mm.
5
In order for concrete for the strip foundation to correspond to the most acceptable brand M-200 (B15) for it, the following laying criteria must be adhered to: 2.8 kg of sand and 4.8 kg of gravel or crushed stone will be required for 1 kg of cement. To prepare M200 concrete from M500 cement, the following proportions will need to be observed: for 1 kg of cement, you need to take 3.5 kg of sand and 5.6 kg of aggregate. It is under these rules that the M-200 (B15) mortar is manufactured in the factory.
6
It is difficult for an individual developer to maintain the parameters corresponding to the production process. Therefore, with independent preparation of concrete, experts recommend adhering to this rule: for 1 part of cement, you need to take 3 parts of sand. The amount of aggregate should not exceed 40% of the total volume of the mixture. Water is added gradually to the concrete mixer, achieving a paste-like consistency of the solution.
