Concrete production today has been mastered not only by professionals, but also by private developers; this has made monolithic housing construction technology available. Such buildings are more durable than all other types of buildings. Previously, industrial facilities and multi-storey buildings were built using this technology. Today, this technique is known to private craftsmen who use it to build their own houses and cottages. Using monolithic technology, you can realize incredible and bold design ideas.
Future homeowners are increasingly thinking about the construction of monolithic houses, as such buildings are surprisingly durable. They are able to withstand even a small earthquake. And the work does not involve large labor costs in the construction process. Expensive materials do not need to be used, and during operation the house is durable and reliable. You can decorate such buildings with any facing material, it is permissible to erect walls immediately with additional thermal insulation.
Features of removable formwork
Monolithic reinforced concrete can be poured into removable or fixed formwork. The first variety is more common and well-known. After the initial setting of the mortar, the craftsmen will need to dismantle the material, leaving the structure to dry completely.
If reusable formwork is used, it will be possible to form a variety of forms for pouring concrete. You will be able to build a foundation, form a frame of a multi-storey building, equip monolithic walls and stairwells, as well as create elements of interior and exterior decor. Monolithic reinforced concrete walls are poured into removable formwork, for which:
- wood array;
- steel sheets;
- combined variations;
- aluminum molds;
- sheets of plywood.
Polyvinyl chloride coating is quite common, which facilitates the dismantling of multi-turn formwork. Metal options are used for the construction of complex structures and in cases where massive construction technology is used. To create the formwork of the foundation, it is best to use plywood, beams or wooden boards. You can facilitate the installation process by using metal frames into which wooden boards are installed. Formwork plywood can only be used to create a small concrete structure or thin partition wall.
Rules for the construction of removable formwork
If youIf you want to pour monolithic reinforced concrete, then you can use a removable formwork solution, however, certain requirements are imposed on it. The frame must be firmly fixed in place and have the qualities of rigidity. The individual elements of the overall design must be precisely fitted to each other. In this case, the gaps should be minimal.
In terms of height, the formwork must withstand significant pressure, which will be exerted by the mortar after pouring. It is desirable that the removable formwork has poor adhesion to concrete. If it is applied several times, then the structural elements should not deform from the impact of the load.
Preparation of wooden elements
If you want to pour monolithic reinforced concrete yourself, then you should choose wooden boards, the thickness of which can vary from 25 to 50 mm. The width of such elements can be very different, this parameter does not play a special role. However, as the width increases, the probability of cracking increases. It is better to choose boards whose width varies from 200 to 300 mm. The boards should be assembled into boards, the height of which should correspond to the future level of pouring concrete. To do this, apply the bars to which the boards are strengthened.
Beams should be located on the outside, while the nails are driven into the boards so that the hats are inside the formwork. It should be as close as possible to fit the boards together with the ends. If gaps were formed with a width of 1 to 5mm, then they are covered with tow. If there are gaps of a more impressive size, they should be hammered with slats.
For reference
Monolithic reinforced concrete will not get the desired strength if there are gaps in the formwork, as cement milk from the mortar will seep through them. In addition to the shields, bars should be prepared, the length of which should be 1/3 greater than the height of the formwork. Boards and wire are used to form the spacers to tie the walls by installing internal lintels.
Formwork device
Below, an example of the formation of a formwork structure for a strip foundation will be considered. These principles will allow you to build fences for most other purposes. First, the surface is prepared, a trench is dug for the foundation, a sand cushion is laid on the bottom. The layer of this preparation should be 150 mm. The resulting base is compacted and abundantly wetted with water. To simplify the process of determining the correct location of the walls of the formwork, its base should be made as strong as possible. To do this, it is covered with a cement-sand mortar or poured with a thin layer of concrete. Horizontalness should be verified using the building water level.
Formwork for stairs and ceilings
If the formwork for the stairs is being installed, then a foundation should be formed at the installation site of the structure, which is connected to the main base of the building. When creating slab formwork,create a base of shields that are supported by telescopic racks. The base area is fixed not with beams, but with I-beams and wooden beams.
Method of work on creating formwork
Once you have leveled and strengthened the base in the trench, you can begin to install the formwork. Using rope and pegs, outline the perimeter of the formwork elements, following the requirements of the project. Along the perimeter of the foundation, pegs and bars are installed on all sides. Surfaces that face the foundation must be removed from the marking line at a distance equal to the thickness of the formwork panels. Pegs are needed to hold the bottom of the shields, while the bars will become the basis for the props. Wooden shields should be attached to the beams and pegs, fastening with nails. The inner surface of the shields should repeat the outer shape of the future base.
Expert Tips
If after you want to grind on concrete, then you should indent the edge of the formwork from the marking by 15 mm. The upper part of the support bars must be additionally fixed with props. To do this, use a board, the length of which should be 1.5 times greater than the height of the foundation. With one edge, it will rest against the upper part of the support beam, while with the other - against the soil. With a large thickness of the foundation, when the supports may not withstand the pressure, it is necessary to carry out a bunch of formwork with additionaljumpers. They are made of wire rod, which will allow you to tie opposite shields.
Technology for erecting buildings with fixed formwork
Formwork for concrete can be non-removable, this technology is most often used today in the construction of cottages. In this case, the formwork elements will act as an additional layer of thermal insulation. The cost of work will be as low as possible, since labor costs are negligible. After the formation and waterproofing of the base of the building, formwork is installed on it, which looks like expanded polystyrene molds. They are attached with profiles. The molds have a thorn-groove locking system, which allows you to connect the elements firmly and without gaps. This completely eliminates the possibility of penetration of the solution and the occurrence of sagging at the junction of the forms.
Formwork can have completely different thicknesses, but blocks are considered standard in which the empty space has a width of 150 mm. At the same time, on both sides there is polystyrene foam with a layer of 5 to 7.5 cm. This will be enough to keep the house warm in winter and cool in summer. When buildings are built from monolithic reinforced concrete using the technology of creating fixed formwork, concrete is poured into the latter after installation. As soon as its layer reaches a thickness of 50 cm, the material should be compacted with a vibrator.
Important to remember
It should be noted that only concrete can be used for pouring fixed formwork, the use of warm mixes is excluded. This is due to the fact that the vapor permeability of expanded polystyrene is low, and the vapor permeability of warm mixtureshigher. If warm concrete is sandwiched between layers of thermal insulation, then condensation will accumulate inside, during which fungus and mold will certainly form. This technology of monolithic reinforced concrete does not provide for the need for additional insulation. The walls will need to be plastered with a decorative composition or sheathed with siding. The advantage of the technique is the simplicity of the work, low cost and no need for additional insulation. However, the cottage will not be able to breathe.
Precast technology
The main difference between reinforced concrete prefabricated elements is that they are not assembled on construction sites, but in factory conditions. This allows for higher product quality. At the manufacturing stage, highly mechanized machines are used, as well as fully automated equipment. The price of such structures is lower, since the complexity of the process is minimized. Precast concrete is produced taking into account the insignificant costs of formwork installation, since in this case it is reusable.
Reinforced concrete structures are divided into four classes according to their purpose, namely:
- for industrial facilities;
- Reinforced concrete products of different profiles;
- for the construction of civil and residential structures;
- for engineering structures.
Precast concrete for civil use includes floors, flights of stairs, panels, landings, foundation concrete blocks and wall structures. For industrialuse reinforced concrete columns, column foundations, piles and floor slabs.
DIY precast concrete
The formwork device will also need to be carried out if you yourself want to make reinforced concrete products. At the same time, some home craftsmen believe that it is not at all necessary to spend money on reinforcement, since concrete already has high strength and reliability. However, in 90% of cases, the load-bearing elements are combined loads, namely tension and compression. The reinforcement will undergo tension, preventing the structure from breaking. Concrete will only withstand vertical loads well when it has the shape of a regular cube, which can only be achieved in laboratory conditions.
Conclusion
The production of concrete for pouring the foundation must involve the observance of the ratio of ingredients. So, the proportion of cement, sand and gravel is as follows: 1:3:5.
