What is it and what is it for?
When building a house under the foundation or screed, it is necessary to make a hard layer in the form of a lining of sand or gravel with fine dispersion. The tamping technique allows to provide the necessary density to such a base. To compact bulk materials, specialized equipment is used, and if the coverage area is small, a manual method of work is used. A sandy dense pad is necessary before starting construction work for the following reasons:
- for full leveling and increasing the degree of rigidity of the base surface of the future structure being built;
- to prevent the destruction of the foundation structure under the influence of moisture or low temperatures, when the soil begins to swell from excess water;
- to prevent the curvature of the structure from the action of bending and compressive loads on it during soil shrinkage processes;
- in order to eliminate hidden voids filled with air;
- for the construction of an intermediate stable layer formed between the soil and the foundation structure.
The compacted sand creates a dense and durable layer, which is a reliable base for laying asphalt pavement, paving slabs, and building foundations. A properly formed sand layer is not subject to deformation and does not collapse if you step on it. Compaction technology implies performing these works in multiple passes over the entire surface of the sand layer.
Upon completion of these actions, the quality is assessed not only visually, but also with the help of special devices.
In order to carry out preparatory work for construction, a sand cushion can be formed by various methods. Their choice directly depends on what kind of tool is in the equipment, how large the area of the working surface is, as well as what are the requirements for the density of the sand substrate.
There are several methods of performing work associated with compaction of sand.
- A self-driving machine is used, which, with the help of its wheels, ramps the sand. Sometimes trailed-type special equipment is used, equipped with rollers for rolling, with the help of which layer-by-layer compaction is performed in several passes.
- With the help of a crane, slabs weighing up to 2 tons are dropped onto the working platform.
- Sand can be compacted with a vibrating plate. a special mechanical device.
- With the help of a channel or a wide bar, sand can be compacted without a vibrating plate, that is, manually.
The selection of mechanized methods for ramming bulk material depends on the convenience for the operation of specialized equipment, the availability of access roads for it and the thickness of the sand substrate required by the project. On large areas, work is carried out using self-propelled tractors, and small areas are processed by self-propelled rollers. If you need to compact the sand in a very small confined space, a manual compaction may well be suitable for this case.
In order to efficiently tamp sandy bulk material, several passes are made using a tool on the same working surface, and the tamping movements are performed in a spiral direction. this way you can be sure that there will be no untreated areas of the substrate surface. If, after compaction, the material has subsided greatly, it is possible to add sand to those areas where it is clearly not enough. For a denser compaction of sand particles, it is regularly poured with water, which helps to push air between the grains of sand.
Tamping is carried out by dropping monolithic heavy slabs, if the pillow consists of clay and sand of a dusty fraction. Such substrates contain air in their multiple cavities, which comes out to the surface under the weight of the monolith. The slab with the help of special equipment rises to a height of up to 2 meters and is dropped onto the working surface flat. This method allows you to work through the clay-sand mixture to a depth of 1.5-2 meters. Usually, this method is resorted to when the foundation for the foundation of a capital structure is being prepared.
A work process of this kind is carried out in a continuous mode, but at a fast pace. This continues until the desired result is achieved.
The manual method of forming a sand layer is resorted to when the treated area is small, and the thickness of the sand layer is small. To solve a similar problem, the tool is made from scrap materials. Take a bar of wood, a wide base in the form of a wooden or steel plate is attached to it perpendicularly. The attachment points of the two parts are securely fixed using hardware fasteners or a weld. The result of the work should be a solid construction for manual labor. It has a lot of weight, but a person is able to lift it and perform frequent blows on the sand. To work more efficiently and faster, the horizontal plate is specially weighted with the help of additional metal plates or pouring from cement.
All about compaction of sand
Before the installation of foundation structures or preparatory work under the screed, as well as for laying paving slabs, it is necessary to tamp the sand cushion in order to expel the excess air volume from it, squeeze the fine fractions of sand grains together as tightly as possible. After compaction is completed, the sand base becomes very dense, ready for further construction work. To cope with this task, mechanized and manual methods of compacting bulk material are used.
How to ram properly?
In order for the frame of the building foundation to be strong, the sand area must be perfectly flat and very dense. This effect is achieved due to the fact that with a well-executed ramming, the required shrinkage is guaranteed at the substrate. Whether it is true or not, after the end of the work, the result must be checked. Quality control of work is carried out with a rope pendulum or level.
In order to properly and with high quality compaction of sand with a vibrating plate, the following important nuances should be observed:
- the vibrating plate will show its effectiveness if the thickness of the sand layer does not exceed 0.6 m;
- before starting work, the sand layer is soaked evenly with water, but this must be done evenly and without frills;
- on the working surface, it is necessary to perform 5-7 passes in both directions.
As soon as the layer of sand is reliably compacted, you can pour in the next batch of sand to continue working. But the thickness of this layer should not exceed 0.6 m.Layers are added until the result is a dense sand cushion of the required thickness according to the project documentation.
For arranging garden paths, before building a garage, before installing the foundation of a country house, a sand pillow is often prepared manually. Sand ramming can be done with a vibrating plate or manually. Self-preparation of the surface will be much cheaper than hired craftsmen.
Consider how manual sand compaction is performed.
- They purchase a ready-made or independently make a device for manual ramming of the T-shape. a horizontal plate is made about 30×30 cm in size, and its weight should be at least 15-20 kg. For the convenience of work, 2 handles are attached to the handle bar on the sides. these grips are needed so that the device can be lifted with two hands at once. If the ramming structure turns out to be too light, it is additionally weighted down with metal or cement.
- With the help of a self-made tool, uniform and repeated blows are applied to the working surface of the sand mixture. With the help of these blows, it is possible to achieve the removal of voids and air, as well as to compact the sand fractions together. Tamping is performed layer by layer. when 1 layer is tamped, the next portion of sand is poured on top of it.
The process of compaction of sand is not so difficult, but quite a crucial stage in construction. The success of all further work depends on the quality of its implementation, so you need to approach it carefully and conscientiously.
The following video shows sand ramming.
How to use a vibratory plate
And although each vibrating plate includes instructions for use in the delivery set, questions about the use of the tool arise quite regularly.
The working capabilities of the vibrating plate are directly related to its weight. The greater the weight of the equipment, the greater the layer of material it is able to compact, tamp. The table below shows general data on the functional features of various vibrating plates.
Vibratory plate weight, kg
Type of material to be sealed
Sand, crushed stone, other non-cohesive soils
Silty weakly cohesive soils
Cohesive soils (clay, sandy loam)
How to properly tamp crushed stone with a vibrating plate
The main difficulty when working with crushed stone is that it is usually represented by different fractions. The maximum thickness of the poured layer is determined immediately before the work of the vibrating plate. As a rule, 3-5 passes are enough for ramming, after which a sufficiently high-quality compaction occurs. Further compaction is meaningless.
When working with crushed limestone, builders have to deal with the clinging effect, when the top layer of stones, under the influence of vibrations emanating from the vibrating plate, adheres tightly. In this case, the underlying stones are not compacted. To combat this effect, you need to use heavier equipment. For example, when operating a vibrating plate weighing 100 kg, you can qualitatively compact crushed limestone with a fraction of 10. 20 mm.
How to tamp sand with a vibrating plate
The procedure for compacting sand using a vibrating plate is as follows:
- the layer thickness should not exceed 60 cm;
- the surface of the entire sealing area must be evenly wetted with water. Water is required so that excessive dust does not rise during work, which has a detrimental effect on filters of construction equipment. At the same time, excess moisture should be avoided, only a moderate amount creates the desired cementitious effect;
- it takes about 3-5 passes with a vibrating plate;
- if the achieved degree of compaction suits its characteristics, then the next layer can be poured, etc.
How to lay tiles with a vibrating plate
Laying paving slabs using a vibrating plate is not much different from the usual compaction procedure. The only prerequisite is the presence of a special polyurethane or rubber mat, fixed on the working body of the equipment. The mat is necessary in order to avoid unnecessary damage to the tiles. Plates made of polyurethane are preferable because they are more wear-resistant and do not leave black stripes on the surface of the pavement.
Preparation of the base
The attractiveness and durability of the future coating will depend on how the technology of laying paving stones on sand is followed. The main condition for its observance is a thorough preparation of the base.
The ground is well leveled, plant roots and large stones are removed; pits and potholes are filled up. A well-leveled surface is compacted with a tamper, which you can do yourself.
The soil must be chosen to such a depth that the surface of the site, taking into account the sand cushion and the height of the bar, is equal to the ground level or slightly higher. Otherwise, water will accumulate on the paved area after rains.
A geotextile is laid on the prepared base and covered with sand with a layer of 10-15 cm. The pillow is carefully leveled, then a slope is made to drain the water, taking into account the “5% rule”. Sand for paving stones is well watered and compacted with a vibrating plate.
The final stage of laying
After the paving stones have been neatly laid out, strengthened and tamped, the paved area should be covered with sand to fill the joints. The question may arise, what kind of sand is needed for paving stones? The answer is unambiguous: fine wet river sand. Then you will need to process the paving stones again with a vibratory rammer. You can use the old old-fashioned way, when the sand was rubbed into the joints with an ordinary mop with a hard nap.
How to lay paving slabs on sand
If you follow the laying technology, then the surface of the track turns out to be smooth, beautiful and durable. Every detail is firmly secured in place. But for a lasting result, the surface of the plates should be compacted with a vibrator. After that, the path should be lightly sprinkled with a layer of sand so that it fills all the cracks and voids. The next day, you need to wash off its remnants with a stream of water and the track can then be used.
How to properly lay tiles on sand
Larger paving stones are used as a curb or special curbs for construction are used. A cord is fixed to the height of the curb and a trench is dug, which is filled with rubble. With a layer of one and a half centimeters, cement mortar is applied and a curb is installed. Using a rubber mallet, the curb must be aligned until it touches the cord. Then the curb is fixed with a concrete mixture prepared in a 1: 3 ratio of cement and sand.
Paving stones are laid on a sand cushion
After installing the curb, it needs to dry well, therefore, the paving stones are laid only after 24 hours. Before placing the paving stones on the sand, it must be spilled abundantly with water. In accordance with the selected pattern, the paving stones are laid close to each other. The coating is leveled with a level, and the bars are knocked out with a rubber mallet as necessary. If necessary, use an angle grinder with a diamond disc to cut the paving stones into small pieces.
When the laying of paving stones on the sand is finished, it is advisable to compact the entire surface with a vibratory rammer using a special rubberized base, in order to avoid damage to the tiles.
The technology of laying paving stones on sand
In recent years, paving stones have been widely used to cover park and garden alleys. This is especially true for individual construction, where chipped talcomagnesite paving stones are used.
The paving stone attracts developers with its beautiful appearance, uncomplicated installation technology and ease of maintenance. All this makes paving stones very popular both in cities and in rural areas.
Paving stone is a material made from various types of natural stone (granite, quartzite, sandstone) or concrete. The main difference from paving slabs is the geometric shape volumetric rectangle. Depending on the manufacturing method, it can be chopped, tumbling, sawn, sawn-chopped.
Compaction of sand
It is necessary to remember about the peculiarities of work in such a case: dust may rise, due to which the environment is polluted, and also the air filter becomes clogged. To avoid this, prepare the work surface in advance: moisten the sand with water, so that it compresses better.
The main conditions and principles of working with a vibrating plate
One of the first questions from users: how to start a vibratory plate. The nature and order of actions depend on the type of mechanism. Most modern models are easy to start, just press the start button. There are also devices equipped with a manual starter. in this case, you need to pull the cord, you need to do it smoothly, and then let the equipment warm up.
It is not difficult to use a vibrating plate. You just need to know the basic rules of its operation and observe them in practice:
- It is necessary to remember safety precautions all the time! The user must sit behind the appliance. Do not bend over the stove.
- If you need to unfold the device, follow the recommendations: use one hand for this, while quickly moving behind the vibrating plate.
- You can work without interruptions no longer than 40 minutes, after that you need to give yourself a rest and vibrating plate (10-20 minutes is enough).
Now you know how to work with this technique correctly. Let us consider in more detail the conditions for using the vibratory plate when performing certain tasks.
Compaction of crushed limestone
Working with large crushed limestone is not as easy as it seems. Due to vibration effects, material particles are collected in a large layer that cannot be compacted. In this case, the lower layers remain unconsolidated. To prevent this from happening, you need to use plates weighing 150 kilograms or more. If the vibrating plate weighs 100 kilograms, it is better to use crushed stone with a fraction of up to 20 millimeters.
Compaction of crushed stone and gravel
It all depends on what kind of material you are working with. In any case, the use of a vibrating plate gives results after four times the surface treatment. If you have already completed four approaches, but the compaction of rubble has not occurred, then this will not bring results in the future. In this case, it is necessary to pour in thinner layers.
When working with crushed stone, it is recommended to work incrementally, that is, gradually, each time to increase the thickness of the layer.
How to work with a vibratory plate
The main conditions and principles of working with a vibrating plate.
Compaction of sand.
Compaction of rubble and gravel.
Compaction of crushed limestone.
Sealing the sidewalk area.
It is important to know how to work with a vibratory plate. Thanks to the competent operation of the device, you can achieve the durability of the equipment, ensure safe working conditions and excellent work results.
Sealing the sidewalk area
If compaction of paving slabs is required, either a damping plate or a polyurethane mat must be used.
Polyurethane mats are more durable and durable, do not leave any marks on the surface.
Remember that the plate compactor must be lightweight. in the region of 70-90 kilograms. Too heavy a product can lead to a violation of the integrity of the paving slabs. Also watch the power level when working. an increased indicator will cause the destruction of the geometry of the product.
To ensure safe working conditions, you need to know how to use the vibratory plate correctly:
- Before each stage of work, you need to check the equipment.
- Check regularly that there is enough oil in the hydraulic system and the engine.
- Monitor the fuel level in the engine and refuel if necessary.
- It is important to check periodically for fuel or oil leaks.
- Inspect the vibrating plate before work for all parts and their reliability of installation, as well as for defects.
- Switch off the engine immediately after work and during breaks.
You can ask other questions about vibrating plates to our consultants.
How to properly ram sand and crushed stone with vibrating plate?
When compaction of the sand layer before starting work, it must be moistened to avoid dusty environment, clogging of the filter and overheating of the equipment.
When working with crushed stone, the characteristics of this material are taken into account. It is recommended to tamp solid granite and gravel crushed stone on an increasing basis. First, the thinnest layer is poured, the thickness of subsequent layers is gradually increased.
Certain difficulties are presented by tamping of coarse-graded limestone crushed stone. To compact fractions more than 20 mm, it is recommended to use only heavy vibratory rammers. weighing from 140 kg. When using a lighter technique, the bottom of the backfill may remain unconsolidated. Aggregates weighing about 100 kg are suitable for fractions of 20 mm and less.
How to properly work with a vibrating plate when laying paving slabs?
For ramming the laid paving slabs, it is recommended to use rammers weighing 75-100 kg. The use of heavier devices may cause the paving stone to split or sink below the general level if placed on a sandy base.
When sealing tiles, experts advise using damping pads, the functions of which are performed by rubber or polyurethane mats. Rubber mats are cheaper but have a limited lifespan. Another disadvantage of these products is the appearance of black marks on the surface of the paving slabs, which are washed off after several rains. Polyurethane rugs are more expensive but more durable and do not leave dark marks.
How to work with a vibrating plate?
Before starting operation, the unit must be inspected for external damage, the reliability of fastening parts and mechanisms, the presence of a sufficient amount of fuel (for internal combustion engines) or voltage in the mains (for electric models). Before turning on, the vibratory rammer is placed on a flat surface.
The procedure for starting up the equipment depends on the model. Budget units are equipped with a manual starter. a cord that must be pulled gently and smoothly. Modern models have a start button.
Basic rules for working with a vibratory rammer:
- The operator must be behind the machine and must not bend over the operating equipment.
- If a turn is required, the operator must quickly pass over the rammer by turning it around with one hand.
- The duration of operation without interruption is indicated in the passport. Usually it is 40 minutes. The required technological break is 10-20 minutes. Exceeding the established period of continuous operation leads to equipment breakdowns and its rapid failure.
- The mode of operation of the unit depends on the thickness of the compacted layer and the characteristics of the bulk material. It is forbidden to make additional efforts to increase the compaction intensity.
How to work with a vibratory plate?
Compaction of bulk materials. soil, sand, crushed stone, gravel. is an event that can be significantly accelerated by using a vibrating plate. This construction equipment can be powered by electric, gasoline or diesel engines.
The technique is quite simple to operate, but you need to familiarize yourself with the rules and recommendations of the manufacturer, how to use the vibrating plate correctly when ramming various materials.
Scopes of vibratory rammers
This construction equipment is used to compact soil, sand, crushed stone, gravel, sand and crushed stone or sand and gravel mixtures. The scope of the tool depends on its mass. The larger it is, the thicker the layer, which can be compacted in one pass.
- Lightweight models weighing up to 75 kg are effective for paving slabs and landscaping. Maximum thickness of the rammed layer. 150 mm.
- Universal rammers weighing 75-90 kg are in demand when arranging foundations for foundations and floors, laying asphalt, partial repair of roads, construction of sports and playgrounds, and parking lots. Thickness of the compacted material. up to 250 mm.
- Vibratory plates of medium weight have a mass of 90-140 kg and can be used for compaction of foundations for a foundation, backfilling of trenches in which engineering communications are laid, for strengthening embankments, for constructing road embankments. The rammed layer. up to 600 mm.
- Heavy models weighing more than 140 kg are used in the construction and repair of large-sized objects.
Safety precautions when compaction of bulk materials and paving slabs with vibrating plates
Basic safety rules when working with vibrating plates:
- The operator must use protective clothing and earmuffs to operate the machine.
- It is forbidden to leave the tool in working mode unattended.
- When compaction of an inclined surface, the movement is made from top to bottom.
- It is forbidden to operate the unit in a fire and explosion hazardous area.
- When overturning, the vibrating plate is first turned off and then returned to its original position.
Special care must be taken when activating rammers without soft start function.
Overview of sand compaction methods
In the construction business, one of the most important details in the construction of any building is its foundation. Before laying the foundation, it is necessary to compact the soil. The technology must be followed as accurately as possible, otherwise it can lead to shrinkage, which will lead to cracks both in the base and in the walls. Any kind of breach will affect the budget, as the building will become less warm and heating costs will increase. The longevity and reliability of the entire building also depends on how well the soil was compacted. Therefore, sand serves as the basis for the implementation of many construction processes.
Tamping sand under the foundation is necessary in the following cases:
To avoid moisture penetration under the foundation or under the screed.
For uneven surfaces.
To prevent compression and stretching. Sand ramming technology will be able to prevent the shrinkage of the building.
Sand and water will be great helpers for problematic soil such as heaving soil or peat. The seal will maintain the integrity and reliability of the foundation.
What sand is desirable to use?
The ideal option for ramming would be gravelly sand, and we categorically do not recommend using a fine and fine fraction. Preference should be given to a large one, as it is more resistant to compression, which will prevent the building from shrinking in the future. In order to establish monolithic structures, it is advisable to use river or quarry sand of the middle fraction. In order for groundwater not to affect the sand layer, before filling a trench or foundation pit, it is necessary to make the installation with an insulating geotextile.
When arranging a sand cushion or preparing a concrete solution, it is recommended to sift the sand before using it. This eliminates various additives that can negatively affect the workflow. The moisture level, according to experts, is considered ideal if you cannot blind a lump. Too much clay will adversely affect the tenacity of the material. This will reduce the strength of the mortar, which is considered one of the main meanings of the design. The mobility of the soil composition changes depending on the moisture content, therefore, you need to be careful when choosing weather conditions for construction work, take into account their properties and make adjustments. The optimum moisture content for sandy soil is 8-14%.
The technologies that make it possible to make a seal are based on mechanically displacing air from it, which, if everything is done correctly, will be no more than 5%. Compaction should be performed in optimal weather conditions, taking into account humidity. Only in this way will you get the desired result. There are several methods for implementing this procedure. It can be done manually using a homemade bar with handles or using a special technique. Let’s consider all possible methods in more detail.
The result is achieved by the static pressure of the drum or wheels of self-propelled or trailed rollers. Uniaxial models weigh from 10 to 25 tons. Lightweight devices are assigned to loose soil of 20-30 cm layer with a gripping width of 2.5 m. Two-axle (using trailers) can weigh up to 50 tons. They provide soil compaction with a layer of 30-35 cm.The working width is 2-3.5 m.
The most efficient semi-trailed rollers weigh about one hundred tons. They take on dispersed soil with a layer of 40-50 cm. Their coverage reaches three meters. The rollers run 4-12 times (depending on weight) one section at a time. Self-propelled and trailed drum rollers are in greater demand than cam rollers due to their wide spreading area. Often, a spiral-ring scheme is used in the rolling work. The number of machines for sandy soils is usually 2-3, and for clayey. 3-4.
The method is based on the use of a vibrating plate, from which mechanical vibrations are transmitted to the compacted soil. The advent of this technique has made it possible to successfully prevent possible soil shrinkage and to carry out fast and efficient compaction. It is distinguished by its reliability, compactness, mobility and ease of use. With its help, work is carried out on the construction of massive structures, shopping centers, multi-storey buildings. Vibration can be superficial or deep. Depending on this, a spiral ring or shuttle system is used. In the process, water and air are squeezed out of the cultivated soil.
Gasoline vibratory rammer.
Today the vibratory rammer is becoming more and more popular. The main advantage of this method is the increased impulse of force and the increased time of impact on the ground. With its help, it is possible to compact the layer by one centimeter with a total thickness of one meter or more. The price of rollers fluctuates depending on the size and condition.
The vibratory rammer is used in cases where sand has poor adhesion. The most dense packing is done by the movement of mineral particles in a vibrating unit. The process is influenced by the general characteristics of vibration compactors (amplitude and frequency of vibration, mass, support area) and soil composition. Modern vibratory rammer makes it possible to compact the layer up to 30-50 cm.
The vibratory rammer differs from the compaction of sand with a vibratory plate in its parameters. The amplitude of vibrations in the vibro-shock mode increases, but at the same time it loses in frequency. The electric rammer is a great companion in areas with limited ventilation and trenches. The equipment used for this purpose helps to achieve a greater depth effect than under static pressure, therefore it confidently occupies about 70% of the market.
It is produced by ejection of slabs weighing up to two tons from a height of one or two meters by a crane. This method is relevant for cohesive soils with a pronounced deformation of the plastic type or for those in which sand serves as the basis. The ramming is carried out using special machines with electric, gasoline or diesel engines. There are a lot of varieties, the price for them fluctuates in the region of three to five thousand dollars.
Compaction of sand by hand
Ramming under the foundation is also possible manually. This is energy-consuming physical labor, which will have to spend a lot of time and effort. However, if the goal is “compacting sand in small volumes”, then there is no need to call professional teams, the price of which is from fifteen dollars per square meter. You can even manually create a construction tool for sand. a crush. To do this, use a fairly wide wooden beam or a steel plate. They can be both light (about 30 kg) and heavier (up to 80 kg). Naturally, manual ramming will not allow deep compaction of the soil. This must be taken into account when choosing a method.
Tamping by hand can make it possible to make a special cushion under the screed, the main material of which is sand. It is imperative that you first use tamping with water, taking into account the degree of moisture in the sand, otherwise all efforts may be in vain. Water is a necessary thing in this process, its volumes are important to control. For example, in order to seal under a screed, sand should be covered with a thin layer (about 10-15 cm). Then water is applied in small quantities and then compaction is performed to the desired depth.
There are many techniques that make sand compaction simple and straightforward. Even a person with little knowledge of construction is capable of participating in it. A vibrating plate and a vibrating rammer are some of the most affordable devices for purchasing. They are optional items to buy. today they can be rented in many places. per day.
The abundance of technology differing in power, size, price, ergonomics, of course, pleases the eye, but still it will not allow you to achieve such a seal as when using heavy tools.
The main criterion for assessing the quality of work is the indicator, which is calculated by the ratio of the achieved soil density to its maximum compaction capability, derived with the help of special GOST devices. The required value for the foundations of buildings depends on the project, but often. not less than 0.98. It is a factor that has no size. Soil density control takes place thanks to field and stationary laboratories.
Which sand is best to use to create a pillow
Gravelly sand is used to create the foundation cushion.
For the construction of a high-quality sand cushion, experts recommend using coarse gravel sand. At the same time, it is categorically not advised to use a thin and fine fraction, because such a material negatively affects the resistance to compression, and this fact in the future threatens with severe shrinkage of the entire structure. In order for a reliable monolithic slab to be installed in accordance with all the requirements, it is advisable to use clean river sand of the middle fraction.
As a last resort, you can use quarry sand. But in order for the sand layer to serve for many years, not to be destroyed and washed by groundwater, before filling a trench or foundation pit, an insulating material should be laid. geotextile. Why is this needed? This precaution will effectively prevent sand and soil from mixing in the future.
Materials and tools used:
- pegs and rope;
- insulating material. geotextile;
- level and tape measure;
- an excavator for digging a hole or a shovel for the manual method;
- dump truck for sand delivery;
- vibrating plate, manual vibrator or large round bar with handles.
Compaction of sand under the foundation
When erecting any structure, specialists take into account everything, even the most insignificant stages, which during further construction can become an important link in such a long process. They can even influence the operation of the building in subsequent years. At the same time, quite often experts ask the following question: why do we need a foundation for a house and why should it devote so much time and effort?
The foundation is the foundation of the whole house as a whole. Without it, a strong and reliable building will not work. Therefore, great attention should be paid to its construction.
The basis of any capital structure is a reliable and strong foundation, on which depends how durable and high-quality this building will be in the future.
At the same time, a special pillow for the foundation, which is sometimes not given due attention, which is considered a gross mistake, is the capital basis of the entire structure to be installed.
Monolithic sand cushion and its purpose
When using a sand cushion, the costs are minimal, and the effect is quite good.
By creating a sand cushion, the cost of building materials is significantly reduced. At the same time, private developers have an excellent opportunity to easily and simply replace low-quality soil in the base under the foundation and at the same time make a general and uniform rise in the level of the entire floor. Despite the small material costs and simplicity of technology, such a monolithic slab perfectly copes with all the tasks assigned to it.
Sand base pillow: its advantages
- It becomes possible to create, according to the permissible load standards, a high-quality base for the foundation.
- There is a guaranteed protection of the entire base of the structure from destructive destruction by groundwater.
- There is an excellent opportunity to level the entire site under the foundation of the structure being built.
- And most importantly, this is a relatively low-cost construction stage compared to its value for the entire structure.
When is a sand cushion needed under the foundation??
It is far from always required to make such an arrangement for the foundation of the structure being erected. Therefore, experts recommend that it is imperative to carry out a detailed analysis of the soil on the site where the house will be built. And already on the basis of these data, decide: is such a plate required in a particular case? But most often a sand pillow is necessary to create a reliable and strong house, as well as to protect it from groundwater, flood waters, freezing and thawing of the soil.
Conditions under which it is necessary to install such a layer:
Heavy soil must be tamped with sand, because it deforms during thawing and freezing.
- If, according to analyzes, the site where the house will be built is problem soil. In this case, it is more expedient to compact such soil with sand.
- Be sure to ram the heaving soil with sand, since during freezing and thawing of the soil it is strongly deformed.
- The sand layer is an intermediate link between the base soil and the foundation itself, due to which the settlement of the entire structure in the future is significantly reduced.
To make a flat basement area near a dug pit or trench, experts most often use sand, since a thin layer of sand gives an excellent opportunity to align the bottom of the pit or trench with a horizontal mowing line. At the same time, it is possible to eliminate everything, even minor irregularities of any surface.
Diagram of foundation parameters depending on the type of soil.
Compaction. Jumping Jack Vs. Plate Compactor Vs. Hand Tamper
A building material such as sand is able to actively resist the natural compression process. Therefore, it is necessary to replace the surface layers of the soil with sand in order to avoid settling of the entire structure, as well as to protect its walls and foundation from dampness and moisture during many years of operation.
Sand cushion dimensions:
- The thickness of the layer of the sand bed itself is determined based on certain conditions. Usually the pillow is laid in a layer of up to 20 cm, thanks to this, you can significantly save on the consumption of cement under the foundation.
- As for its shape, it is better to lay a trapezoidal sand pillow, which should taper towards the bottom. The taper angle should be 30 °.
- In this case, the created monolithic slab should not exceed the width of the foundation itself by more than 3 times in thickness.
Sand pillow and its device under the foundation
Strip foundation scheme on a sand cushion.
- First of all, on the site, an appropriate marking of the foundation is made and its main parameters are determined. To do this, use a level, tape measure, pegs and rope.
- According to the markings, a pit or trench is dug to a certain depth, this directly depends on the selected type of future foundation. A pit or trench is dug with an excavator or manually with a shovel.
- The bottom of the pit or trench must be leveled and carefully tamped.
- To create such a foundation slab, sand is poured into a foundation pit or trench in several layers, the width of each layer should be up to 20 cm thick.
- Each poured layer must be well tamped and moistened, but not watered with abundant water. This is especially important in the summer, when the water evaporates faster. Sand that is constantly moistened will give maximum density to the entire sand layer.
- To compact the sand, use special equipment. a vibrating plate. or rent a hand vibrator. If the first two methods are unacceptable, then homemade devices can be successfully used. For example, take a large round bar, attach handles to it and roll each layer yourself.
The number of layers depends on the required thickness of the pillow itself. It is necessary to fill and tamp the sand until the required thickness is formed. In this case, one must not forget to ensure that each new vertical layer is as even as possible, and at the same time to carry out horizontal alignment. The strength and reliability of the entire structure directly depends on this. In heaving soils, with the threat of freezing of the foundation, which has a sand slab under it, the installation of a special drainage is required. Only in this way the sand layer will not be flooded with water and will not lose its original properties.
The base slab is: sand, crushed stone and concrete.
When designing a structure, it is necessary to provide for, and when laying a house, installation work is carried out under the foundation, when a pillow is laid, which still needs to be carefully tamped. Why is it required to ram? Then, so that a monolithic, strong and even slab was created under the base of the structure, the purpose of which is to ensure as little shrinkage of the entire building as possible in the future for many years.
- crushed stone;
Each of them has its own advantages and disadvantages, but this does not mean that each of the listed types of pillows can be suitable for the construction of any house. As a result, each developer is recommended to conduct a certain analysis and find out the condition of the soil. Why you should follow these precautions?
Before starting to build a foundation, it is necessary to examine the condition of the soil, the presence of groundwater, etc.
In this case, when constructing a structure, it is recommended to take into account the peculiarities of the climate, the condition of the soil, the presence or absence of underwater waters, the general parameters and dimensions of the object, as well as various other factors. An incorrectly selected slab for the foundation, as well as a poorly installed one, can lead to irreparable consequences, this includes the destruction and subsidence of the entire base and the appearance of cracks on the walls of the house.
Numerous private developers prefer laying a cushion under a sand foundation, it is distinguished by its simplicity and low cost of building material. over, such a solid slab has one drawback: heavy bulky buildings cannot be erected on it. But in private construction, when planning ordinary houses, there is no need to comply with such strict conditions, and therefore such a pillow has been popular among developers for many years.
How to choose the right sand
When choosing sand, the following factors must be considered:
- Large clay in the sand reduces the strength of the concrete solution itself and negatively affects the adhesion of the material, and this is very important when arranging a sand cushion.
- To create a high-quality concrete solution, sand of the middle fraction is used. For arranging a sand cushion under the foundation, coarse sand is used. It is such sand. with large granules. that is best tamped, and it fits well into dense layers.
- If we talk about the degree of moisture of sand, then professionals check this quality in the following way: sand is considered ideal, from which it is impossible to make a lump.
- Before using sand for concrete mortar or arranging a pillow, it is recommended to sift it so that different inclusions cannot negatively affect the quality of work.
The foundation cushion is the initial layer that forms a reliable and stable platform on which the foundation for the house will be installed. Such a device allows the entire structure to be provided with minimal shrinkage over many years of operation and protects against the negative effects of underwater waters and soil displacement. Most often, professionals use a sand cushion for tape or monolithic types of foundation.