What is necessary concrete cover: how to choose the thickness of the concrete

Concrete is used not only as a solid support member, but also as a protection of metal reinforcement from moisture, extreme temperatures. The protective layer of concrete is poured also between the bottom and the foundation soil: foundation protection against harmful microorganisms, even load distribution during the shrinking.

Also such a layer serves as waterproofing, for use to protect a material with low air permeability.

requirements

The requirements depend on the protection of functional time pads, laying, installation of the main structure.

Between the foundation and the soil.

1. Water resistant.

2. Plasticity of the mixture.

3. The presence of bactericidal agents.

4. Using the respective equipment, depending on the characteristics of the mixture.

For basements - heaters depreciation and moisture permeability of the joint foundation with the soil.

Since the protective layer under the concrete foundation is not in contact with the atmosphere - the frost resistance is not a primary requirement.

to the concrete protection requirements armature

1. Adhesiveness - a snug fit to the fixture.

2. Ability to grasp with other solutions.

3. Frost resistance.

4. Resistance to aggressive compounds.

5. The high thermal conductivity.

6. The relative ease.

7. The rapid solidification of the contours of the valve.

How to choose the thickness?

Installation of concrete protective layer of thick - additional costs. For the protection of steel structures hinged excessive thickness, 5-10 years of operation may cause damage to these. Concrete, accumulating moisture heavier with time.

By SNIP - the following layer thicknesses are used for the different constructions.

1. Under the foundation - a minimum of 4 cm.

2. For cables - no more than 1 diameter.

3. For rods - to 2 diameters.

4. On iron structures - up to 3 diameters.

5. If you want to protect the bundle of rods rope - 32 mm.

Important! Over time, the concrete stronger. It is necessary to take this into account during installation.

The ratio of the thickness and Labeling

Installation of concrete protective layer under the foundation with high performance in the middle zone of Russia is carried out from early May to mid-September. During this period, the optimal hardening of the concrete mix. If the humidity is below 60 - watering for 3-7 days. To obtain high ductility and permeability, better prepare their mixture.

Plastic concrete M50 is short-lived, absorbs moisture. Concrete with low permeability, the M-200 neplastichen - high load during the shrinkage of the soil. To ensure a good frost will have to use the M-350-M400.

Important! Hard mixture not suitable for protection. Because of the small volume of the material - the rapid formation of cracks. High-quality concrete can be used only if there is concrete in the construction of lower grades - damage less robust.

Armature - M-150, and in areas of high humidity - M-200-300. If the main filler gravel - bottom - 0.5 cm of crushed glass, typically bottles, - a good streamlined. Not suitable for wall constructions.

results

Protective layer of concrete is used to protect the valve from weathering and under the foundation in order to minimize harm to the shrinkage. The minimum thickness of the protective layers is registered in SNIP. To protect the valve using a more durable concrete; under the base - plastic.

channel RemontDom thanks for subscribing. Please Like - many thanks!