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Foundation

August 12, 2017 18:06

Can I pour the foundation parts

When pouring reinforced concrete foundation required volumes of the house often exceed several cubic meters.Large construction companies are addressing this problem with the help of heavy machinery - Concrete mixer and, with their help, the solution is mixed and fed into the formwork.However, private developers, this technique does not always afford, in addition, small areas may not be access routes for heavy vehicles.Part of the problem will help solve the concrete mixer, but the volume of the solution being prepared in one load, thus limited.Do builders this raises the question: is it possible to pour a foundation in parts?Does this affect the performance characteristics and durability of the foundation?

Can I pour the foundation parts

Can I pour the foundation parts

stages of maturation

concrete Concrete is a mixture of cement and fillers - sand, gravel, expanded clay - water.To improve the fluidity of the solution, improving cold resistance and impart specific properties in the concrete mix are also added various additives and plasticizers.

slurry after cooking is poured into a form, called a formwork and then the concrete begin irreversible processes:

  1. concrete grasp. During this stage, the liquid becomes a concrete solution to the solid state due to the interaction of cement components and water.However, the connection between the components is still very fragile, and under the influence of the load may be destroyed, and the re-setting of the solution does not occur.

Lasts this phase, depending on the air temperature from 3 hours to 1 day.The lower the temperature, the longer the concrete hardens.In the initial stages of setting it remains liquid without any structural changes.If during this time add a new formwork concrete portion.No destruction of the cement bonds will not happen.For a temperature of 20 ° C 'liquid' stage lasts about 2 hours, at zero temperature, it lasts about 6-8 hours.

can extend the time before the setting of concrete by constant agitation, but it will worsen its characteristics, so abused by this method is not necessary.

  1. concrete hardening. This phase lasts for a long time, due to the progressive hydration of the concrete foundation components gaining strength for years.The first 28 days - this is a mandatory aging period of concrete to set them strength corresponding to its mark.Curing takes place fairly rapidly during the first day, then it slows down the speed.
  2. In the first hours after the setting of concrete hardness is still low, and the addition of the next portion of the concrete may result in microcracks due to the load increase.After three days of hardening, generally, these loads do not have such an impact on the first layers of concrete.

Based on the characteristics of concrete maturing, we can say: pour the foundation parts as possible.In this case you need to follow some rules:

  • The sequential mixing concrete between their parties during pouring into the mold should not exceed 2 hours in a warm weather, and 4:00 in the offseason.Seam is not formed, it does not change the strength of the foundation.
  • If you want to make a long break in the work, it should be at least 2-3 days.After the break the surface of the foundation on which a fresh batch of concrete will be filled, must be cleaned of dust, moisture, and clean with a wire brush.The seam in this case will have a good grip.
  • When pouring the foundation is often necessary to observe all recommendations for reinforcement.
Methods for reinforcing the corner in the basement

methods of reinforcement in the basement corner

layer by layer or blocks?(Pour pieces)

Another issue of concern to developers - how to distribute the concrete portions?There are three types of joints location:

  • Horizontal;
  • Vertical;
  • an angle.

snip on this score gives specific instructions: seam between the sections of a monolithic foundation should be directed perpendicular to the axis.That is, for columns and piles only suitable layered pouring concrete to form a horizontal seams.

to tape the seams monolithic foundation can be placed both vertically and horizontally.To maintain the strength of the foundation must be a qualitative reinforcement, directed perpendicular to the seams monolithic blocks.If the seams are made vertically, the longitudinal reinforcement must always firmly bind the corners of the building.When layered horizontal casting plant vertical reinforcement is required.In practice, the strip foundation is usually poured layers for filling the individual vertical units required an extra casing.

The process of pouring of the foundation

process of pouring the foundation parts

When filling the tape base layers should be considered a feature: if the formwork is raised only in the aboveground part of the foundation and the underground part of the excavated trench is filled in, the joints of the series make the level of the soil.Before filling the cap need to wait for concrete hardening in the underground part in a few days, otherwise the weight of the concrete poured into the formwork, their weight can destroy insufficiently cured cement-hydrated connection.The concrete will be micro-cracks, it becomes more hygroscopic, and eventually begins to break down.

Fill strip foundation

Fill strip foundation

When pouring the foundation slab joints have either horizontally or vertically in a direction perpendicular to the short side of the plate.This arrangement allows the joints to reduce the likelihood of fracture when an inhomogeneous load and soil heaving.

monolithic foundation casting technology

casting technology monotone foundation

Plasticizers

addition of additives and plasticizers can improve the fluidity of the concrete, making of the filling process can be deleted concrete vibration.This will reduce the impact of the new solution is already serving on the drenched layers.

Mixing solution produced after the preliminary calculation.With the addition of plasticizers have to strictly follow the manufacturer's recommendations regarding dosage, since failure to comply with the proportions can lead to the opposite result.

The process of mixing concrete

process of mixing concrete

Video - basic error by pouring the foundation