For the construction of a reliable foundation, certain technologies are used. But one of the cheapest and best options is considered to be a foundation made of rubble concrete. High strength, low cost and easy laying process are the advantages that have made it so popular in the construction environment. In addition, you can organize it yourself, but in this case you will have to follow the instructions clearly so that the result is a quality foundation.
The article will describe the process of laying a rubble concrete foundation, as well as discuss the features of the material and recommendations for organizing the foundation of this type.
General information
The peculiarity of the construction of a rubble concrete foundation is that it is necessary to use natural stone for its masonry. The material must be strong, large, without chips and cracks. Butu includes the following rocks and rocks:
- sandstone;
- bas alt;
- limestone;
- dolomite;
- granite;
- dense shell rock;
- diorite.
Toto organize a reliable rubble concrete foundation with your own hands, then you first need to check the quality of the stone: you should hit it with a hammer. If the building material is strong, then it will not crack upon impact. In addition, there is an artificial block booth, the shapes and sizes of which have a certain proportion. But such raw materials are used during facing works, and they are rarely used for the construction of the base.
Before you start building a concrete foundation, you need to choose the right grade of concrete and rock type. To reduce the cost of construction work, it is recommended to buy materials in those stores that deliver raw materials from far away places: transporting natural stone is expensive. When designing, it is necessary to take into account the fact that the width of the base should be 10 centimeters larger than the outer wall of the building. In addition, you should know: it is better to build such a foundation on solid ground.
Choice of rubble stone
Selection of high-quality material is an important stage in the work on the manufacture of the foundation. Rubbed concrete must be made from stones with torn edges, since rounded cobblestones will not set well with the mortar. Masters recommend using the same raw materials with the following sizes:
- length - 30cm;
- width - 20 cm.
Booth is a strong and durable material, however, when choosing it, the following points should be taken into account:
- Using small stones will increase the consumption of concrete mortar, and too large stones will reduce stabilitygrounds. Therefore, it is better to purchase buta elements, the optimal sizes of which were given earlier.
- Do not use contaminated building material: it does not adhere well to the concrete mix.
- It is forbidden to build a foundation of stones with noticeable defects, as the result will be an unstable foundation.
But there are some tricks when working with this natural material: for better adhesion to the mortar, the cobblestones must be moistened.
Scope of rubble concrete
This building material is usually used in the construction of low-rise facilities that will be located on solid ground. Before you start building a building, you should do a soil analysis on the site.
On loess-like loams and clayey soil, it will be necessary to organize a columnar concrete base, since in this case it is necessary to raise the building above the groundwater level and protect it from flooding. In addition, steel reinforcement or mesh will have to be mounted.
These are the main applications of rubble concrete. The peculiarity of the material lies in the fact that the stones will take heat from the solution, so the work is best done when the weather is warm outside.
Rubbed concrete base: advantages
This foundation is practically a copy of a conventional reinforced concrete counterpart. Most often, the base of buta is made in the form of a tape, and its advantages include the following technical parameters:
- environmental;
- strength and durability;
- beautiful exteriorlook thanks to the use of natural rocks;
- high moisture resistance;
- low cost (no need to buy steel rebar);
- good resistance to the negative effects of aggressive environments and low temperatures;
- withstands the load of multi-storey buildings;
- you can build the foundation yourself without the use of special equipment.
But the main advantage of such a foundation is that the stone is a natural material, thanks to which a reliable foundation will be obtained.
Flaws
The concrete foundation is not the most ideal foundation, therefore it has its own characteristic shortcomings, to be exact:
- The building will not retain heat well due to the tendency of the base to freeze in winter. To eliminate this drawback, you need to cover the base with heat-insulating material (for example, mineral wool, expanded clay or expanded polystyrene), and then veneer and make a blind area.
- High labor intensity of work - the stones will have to be sorted and prepared manually, so builders recommend using rubble concrete for the construction of small foundations.
- For the construction of multi-storey buildings, the foundation will have to be reinforced with reinforcement.
- It is possible to organize a concrete base only if the temperature outside is not lower than 5 °C. Otherwise, the mortar simply does not have time to harden, and this will inevitably lead to the fact that the load-bearing walls of the building will crack over time.
Marking the site and preparing the pit
Building your own base is easy. To perform these works, you will need the following tools:
- shovel;
- building level;
- plummet;
- trowel;
- hammer;
- roulette.
Before you pour the concrete foundation, you need to examine the soil at the construction site. The level of groundwater and the depth of freezing of the earth are the main parameters that need to be studied and included in the project documentation. Next, you need to calculate the characteristics of the base, taking into account the temporary loads and the mass of the finished object.
The technology of the concrete foundation device consists of the following preparatory measures:
- Clear the construction site of debris, plants and other foreign objects.
- Remove the fertile layer, which is known to be 15 cm thick. If this step is neglected, the roots of the plants will rot over time and spoil the final structure of the flooring of the building.
- Mark the site: set the pegs in the places marked in the project, and then stretch a rope or nylon thread between them.
- Dig a trench 20 cm deep below the freezing point of the soil on the site, while the width of the ditch should be 10 cm larger than the foundation itself.
- Pour sand and gravel to the bottom, and then thoroughly moisten and compact the resulting layer, the thickness of which should be 20-30 cm as a result.
- Lay roofing material on a sand cushion like thisso that the waterproofing material goes on the walls of the trench by 15-20 cm
All work is easy to do on your own. However, you can hire an excavator to dig a trench, and it is better to compact the soil with a vibrating plate.
Preparation of mortar
The mixture for pouring must be done in a ratio of 1:3:1, where the first value is cement grade M500 (you can use at least M300), the second is medium-grained river sand, and the third is fine gravel.
The components must be thoroughly mixed, and then you need to add water to the resulting composition. The result should be a not too thick concrete mortar, which needs to be poured into the trench and the gaps between the stones.
Formwork installation
The form must be mounted in such a way that it is wider than the concrete foundation being erected. In addition, the formwork must protrude at least 25 cm above the ground. The walls must be installed end-to-end so that there are no gaps between them through which the concrete solution can flow out.
The above-ground part of the formwork must be strengthened with props made of wooden stakes. Experts also recommend pulling the walls of the structure together with crossbars, which must be connected with self-tapping screws. But there is another important point: the stones must be laid at a small distance from the boards.
However, if there is dense soil on the site, then you can not build formwork. In this case, the walls of the trench must be made even, and then covered with roofing material.
Rubber concrete foundation: construction instructions
This base need not be reinforced, since natural stone already provides a reliable bond. To build a foundation, you need to do the following:
- Spread rubble stones near the prepared trench. This will not only reduce labor costs, but also speed up the construction process.
- Pour concrete mortar into the ditch (this layer should be 25 cm).
- Lay the stones so that they are about 5 cm away from the formwork walls. The distance between the cobblestones should be the same. It is better to lay out the first layer of stones with slightly pointed edges: they will not damage the roofing material.
- Re-pouring a layer of concrete, the thickness of which should be 25 cm. There should be no voids and lumps inside the mortar, and if there are any, the mixture must be compacted with a construction mixer.
- The described work must be alternated until the required base height is reached.
If you strictly follow this simple technology, the concrete foundation will be strong.
Insulation of the base
To carry out these works, you will need to sheathe the foundation both from the inside and from the outside. In addition, along with this process, the construction of the basement of the building is being carried out. To insulate a rubble concrete foundation, you need to sheathe it from the outside with polystyrene foam. To do this, first, dirt and dust must be removed from the surface of the base. After you need to equip it in several layers with a rollbitumen. The final stage is gluing the base outside with the mentioned heat-insulating material.
To protect the building from frost, the plinth should be sheathed with foam. This material must be attached to glue or mastic, and then it is necessary to plaster the structure along the paint grid.
Sometimes builders use a complex technique to better insulate the foundation.
Conclusion
Constructing a concrete type foundation is a simple thing that anyone can do. The article showed how to do it. The main thing is to carefully study the instructions and correctly make preliminary calculations. Even a novice builder, who has all the necessary tools and building materials in his inventory, will cope with this task.
