One of the most popular pillar foundation designs is the foundation of asbestos-cement pipes. This technology is used in the construction of light buildings and frame houses, and its implementation requires a minimum of resources and efforts. In addition, the foundation of asbestos-cement pipes is used in regions prone to flooding - the foundation material has the necessary strength and resistance to wetting and destruction.
Foundation from asbestos-cement pipes
Advantages of the foundation of asbestos-cement pipes
- Ease of implementation, eliminating the need for special construction equipment;
- The contracted terms of works and endurance;
- Simple calculation of the foundation, which you can do yourself, without contacting the project organization.
- Possibility of erection and long-term operation of buildings in flooded areas;
- The low price of materials.
Field of application of columnar foundations
The columnar foundations of asbestos-cement pipes serve as the basis for the construction of light buildings: summer cottages, small baths and saunas, terraces and verandas, as well as frame lighter houses. In regions with a cold climate, such a foundation makes it possible to save considerably, since the penetration of separately standing pipes, both for materials and for the cost of work, is much cheaper than a buried band or block foundation.
Calculation of the foundation of asbestos pipes
For calculation it is necessary to know the depth of freezing of the soil in your region, as well as the planned load on the foundation. The depth of freezing can be determined from the reference data. The reference shows the depth of freezing of bare ground, without snow cover. If your area has a high snow cover, reference data can be somewhat reduced.
Table - the depth of soil freezing in the regions of Russia
To the reference value, it is necessary to add 0.3-0.5 meters - this is the required depth of the underground part of the piles. Above the soil level, piles of pipes usually protrude by 0.3 meters, but if there is a possibility of flooding, they can be made even higher.
The diameter of the pipes depends on the weight of the structure. For light arbors, enough pipes with a diameter of 10 cm, for log buildings it is better to choose pipes with a diameter of 25-30 cm.
The load on the foundation depends on the structure of the structure, and also on the material from which it is made. Below are approximate information on the specific gravity of different materials. When calculating it is necessary to take into account not only walls, but also roofing, insulation and finishing.
Table - loads on the foundation
Piles are located in the corners of the building, at the intersection of the bearing walls, as well as along the perimeter at a distance of not more than 1 meter. The redistributed load on each pile should not be more than 800 kg. If, as a result of the calculation, the load value is greater, it is necessary to increase the number of piles.
Based on the results obtained, the required number of pipes is determined, as well as the required number of reinforcement, based on 2-3 reinforcing bars per pipe.
The amount of concrete depends on the diameter of the pipe. On average, to fill 10 meters of a pipe with a diameter of 10 cm, taking into account the base of 0.1 cubic meter of concrete, for a pipe with a diameter of 20 cm - 0.5 cubic meters, and for a tube with a diameter of 30 cm - 1 cubic meter of concrete.
Technology of pile foundation execution from asbestos-cement pipes
- Preparation should be started with marking. Remove from the construction site garbage and foreign objects, if possible level it and remove the turf. Mark out with the help of pegs and rope contours of the future building, corners, intersections of walls. Mark the place of installation of piles with pegs. To check the perpendicularity of the angles and the correctness of the marking, check the equality of the diagonals.
- Begin drilling wells for supporting poles. This can be done with the help of a drill, and in its absence it is possible to excavate pits with a diameter larger than the diameter of the pipes. The depth of the well is 20 cm more than the estimated size of the underground part of the piles, which is necessary for the installation of a sand pillow.
Borehole drilling process under pile
- Arrange at the bottom of each well a sand pillow 20 cm thick, stamp it and spill it with water. After absorbing water, the bottom is covered with a ruberoid. After that, the prepared pipes are installed in the well. If the pipes have to be cut to the required size, it is necessary to leave a stock of about 10 cm tall so that after the foundation is completed, align the height of the supports.
Process of installation of
- support asbestos-cement pipes. The pipes are leveled, fixed with temporary supports made of wooden blocks. Once again check the equality of the diagonals. In areas with a close groundwater table, the pipes are waterproofed with bitumen-based mastic to ground level. Dry the mastic.
The process of aligning asbestos-cement pipes with wooden formwork
- Concrete is prepared: 1 part of the cement is mixed with 2 parts of sand, diluted with water to the consistency of the batter, then 2 parts of fine gravel are poured into the resulting solution. Well knead and pour the base of the pipe for 40-50 cm
- Pipe lifted by 15-20 cm and left until the full hardening of the concrete. This technique will help create a solid support base that is resistant to ejection forces when punching the soil.
- After the concrete has solidified, the well on the outside of the pipe is additionally waterproofed with a roofing material and covered with river sand, spilled and tamped, checking the installation according to the level. String between them a string or install a bar and align them horizontally.
Foundation of asbestos-cement pipes is ready
- Inside the pipes, reinforcement is installed: several bars connected by cross wires from each other. Mix the concrete and pour the rest of the pipe. To remove air from the solution, pierce it several times with a metal rod.
- After complete drying of the concrete, after two to three weeks, the foundation is ready for further construction. In order to extend its service life, it is recommended to make its waterproofing with bituminous or polymeric materials.
The construction of a pile foundation from asbestos-cement pipes reduces the cost of building a solid foundation under the building several times. However, if the load is too heavy, such a foundation may not be strong enough. In this case, it is better to choose another type of foundation, tape or monolithic.
In conclusion, be sure to read about the bored foundation yourself.
