Preparation of the concrete by hand, on the building site

     In many cases the concrete work at home, in the garage of the house or the office, where it is impossible or unprofitable use of concrete-gun, concrete mixers and other heavy machinery and work to be done manually.
     Displayed below are the amounts deducted from the force before time "Quote norms" kn.02- High construction, since this is the easiest and quickest way to obtain such information.
     Of course, this is old data, but for their own use are adequate enough. At present already operate new regulations, but they are much more demanding than the old information.

Preparation of simple mix concrete at a construction site
(Here, under ordinary concrete mixtures to be understood concrete mixtures, which yield a so-called. Betoni- ie ordinary concrete with a density in the dry state greater than 2000 kg / m3 but not more than 2600 kg / m3) .


Standard humidity (in%) and the density (kg / m3) of the aggregates constituting the concrete:
- Sand beton- average humidity = 6%, Density = 1550 kg / m3;
- Sand solutions: moisture = 8%, Density = 1400 kg / m3;
- 5-10mm gravel, river: humidity = 3%, Density = 1450 kg / m3;
- 10-20mm gravel, river: humidity = 1%, Density = 1450 kg / m3;
- 20-40mm gravel, river: humidity = 1%, Density = 1500 kg / m3;
- 5-20mm gravel, river: humidity = 3%, Density = 1500 kg / m3;
- Crushed stone 5-10mm: humidity = 3%, Density = 1350 kg / m3;
- Crushed stone 10-20mm humidity = 1%, Density = 1350 kg / m3;
- Crushed stone 20-40mm humidity = 1%, Density = 1400 kg / m3;
- Crushed stone 5-20mm: humidity = 3%, Density = 1400 kg / m3;

The use of crushed stone, gravel expenditure norms be reduced by 100 kg and for the cement, sand and water were increased by + 10 kg + 65 kg + 10l.

When preparing the concrete placement with concrete pump, used felt with a grain size up to 20 (30) mm.

The maximum diameter of the large aggregate (gravel or crushed stone) is calculated and depends on:
- The minimum cross-sectional dimension of concreting element or group;
- Inner diameter of the pipe used to transport concrete mix concrete pump;
- The thickness of the slabs or the thickness of the enforced concrete flooring;
- The minimum distance between light rebar;
- The concrete cover of the bearing reinforcement.

The addition of other additives, such as accelerators, plasticizers, retarders and the like. be made only after appropriate laboratory proven quality and quantity, and in conducting systematic checks. (With one sentence: It is not working for everyone!)

Preparation of simple mix concrete at the construction site - Manual
Preparation of concrete class V7.5 construction site - manually 1 m3:

Workforce: concrete workers 2st. = 4.15chch / m3;
Materials:
-water = 0.165 m3;
-pyasak river = 0.610 m3;
-chakal river, crushed = 0.870 m3;
-tsiment MC 35 TO in bags = 165 kg;

Preparation of concrete class B10 construction site - manually 1 m3:
Workforce: concrete workers 2st. = 4.15chch / m3;
Materials:
-water = 0.218 m3;
-pyasak river = 0.520 m3;
-chakal river, crushed = 0.800 m3;
-tsiment MC 35 TO in bags = 255 kg;

Preparation of concrete class V12.5 construction site - manually 1 m3:
Workforce: concrete workers 2st. = 4.15chch / m3;
Materials:
-water = 0.233 m3;
-pyasak river = 0.480 m3;
-chakal river, crushed = 0.800 m3;
-tsiment MC 35 TO in bags = 295 kg;

Preparation of concrete class B15 construction site - manually for 1 m3:
Workforce: concrete workers 2st. = 4.15chch / m3;
Materials:
-water = 0.235 m3;
-pyasak river = 0.430 m3;
-chakal river, crushed = 0.810 m3;
-tsiment MC 35 TO in bags = 335 kg;

Preparation of concrete class B25 construction site - manually for 1 m3:
Workforce: concrete workers 2st. = 4.15chch / m3;
Materials:
-water = 0.250 m3;
-pyasak river = 0.390 m3;
-chakal river, crushed = 0.790 m3;
-tsiment MC 35 TO in bags = 405 kg;



Preparation of simple mix concrete at the construction site - a mechanical mixer (500 liters)
Preparation of concrete class V7.5 construction site - mechanized, for 1 m3 ::
Workforce: concrete workers 2st. = 1.55chch / m3;
Materials:
-water = 0.165 m3;
-pyasak river = 0.610 m3;
-chakal river, crushed = 0.870 m3;
-tsiment MC 35 TO in bags = 165 kg;
Mechanization: 500L mixer = 0.0461mch / m3;

Preparation of concrete class B10 construction site - mechanized, for 1 m3:
Workforce: concrete workers 2st. = 1.55chch / m3;
Materials:
-water = 0.218 m3;
-pyasak river = 0.520 m3;
-chakal river, crushed = 0.800 m3;
-tsiment MC 35 TO in bags = 255 kg;
Mechanization: 500L mixer = 0.0461mch / m3;

Preparation of concrete class V12.5 construction site - mechanized, for 1 m3:
Workforce: concrete workers 2st. = 1.55chch / m3;
Materials:
-water = 0.233 m3;
-pyasak river = 0.480 m3;
-chakal river, crushed = 0.800 m3;
-tsiment MC 35 TO in bags = 295 kg;
Mechanization: 500L mixer = 0.0461mch / m3;

Preparation of concrete class B15 construction site - mechanized, for 1 m3:
Workforce: concrete workers 2st. = 1.55chch / m3;
Materials:
-water = 0.235 m3;
-pyasak river = 0.430 m3;
-chakal river, crushed = 0.810 m3;
-tsiment MC 35 TO in bags = 335 kg;
Mechanization: 500L mixer = 0.0461mch / m3;

Preparation of concrete class B25 construction site - mechanized, for 1 m3:
Workforce: concrete workers 2st. = 1.55chch / m3;
Materials:
-water = 0.250 m3;
-pyasak river = 0.390 m3;
-chakal river, crushed = 0.790 m3;
-tsiment MC 35 TO in bags = 405 kg;
Mechanization: 500L mixer = 0.0461mch / m3;


In short for those who are interested in the properties and laying of concrete mix:

* Classes consistency of concrete mixtures:
Class of subsidence: S1, subsidence: 10-40 mm;
Class of subsidence: S2, subsidence: 50-90 mm;
Class of subsidence: S3, subsidence: 100-150 mm;
Class of subsidence: S4, subsidence: 160-210 mm;
Class of subsidence: S5, subsidence:> 220mm.
* Texture of the concrete compounding sort of degree of density, density or softness of the concrete mix

Vebe ** classes of concrete mixtures:
Class Vebe: V0, weather sealing: ≥ 31sec;
Class Vebe: V1, weather sealing: 30-21sec sec;
Class Vebe: V2, weather sealing: 20-11sec;
Class Vebe: V3, weather sealing: 10-6sec;
Class Vebe: V4, sealing time: 5-3sec.
** Class Vebe- required time in seconds for compaction of the concrete mix

Slurry of the concrete mix, depending on the type of structure:
-Betonova Mixture of elements unreinforced or poorly reinforced sizeable scale concrete elements, such as dams, retaining walls, foundations, concrete base beneath foundations, concrete pavements, runways and others. Ready mix concrete for reinforced concrete products produced by vibropressed and bench technology: Class of subsidence: S1, subsidence: 10-40mm; Class Vebe: V0, weather sealing: ≥ 31sec.

-Betonova Mixture of solid reinforced concrete slabs, beams, columns, walls, etc., Transported by crane vehicle and kyubel. Plates with a thickness of 12cm thick and reinforced with horizontal concrete elements: Class of subsidence: S2, subsidence: 50-90mm; Class Vebe: V1, weather sealing: 30-21sec.

-Betonova Mixture of solid reinforced concrete slabs, beams, columns, walls, etc., Transported by concrete pump. Ready mix concrete for reinforced concrete products produced by cassette (vertical) technology. Concrete mixture that will be applied to concrete pump: Class of subsidence: S3, subsidence: 100-150mm; Class Vebe: V2, weather sealing: 20-11sec.

-Betonova Mixture of thin walls, columns, bunkers, silos and beams with thickness up to 12 cm: Class of subsidence: S4, compaction: 160-210mm; Class Vebe: V3, weather sealing: 10-6sec.

- Concrete mixture with high mobility, designed for densely reinforced, thin-walled concrete elements with a limited ability to seal. Proper consistency for SCC: Class of subsidence: S5, subsidence:> 220mm; Class Vebe: V4, sealing time: 5-3sec.


IMPORTANT:
-Posochenite Above values ​​are recommended!
-If There are guidelines to be observed the prescribed duration of vibration and to provide overlap of vibration zones. Excessive vibration leads to undesirable delamination of the concrete mix and the deterioration of the concrete strength!
-With A time of laying the concrete mix, it is necessary to monitor the design position of reinforcement. During and after the laying of the concrete mix, it is advisable to monitor the state of the elements of the formwork and dolulezhashtata structure that takes loads of formwork (on which foot formwork).

Striking:
If no specific instructions from the designer (and it is mostly the case), stripping of concrete structures shall be allowed when the concrete strength has reached levels not lower of the following:
-for fundamenti- least 50% of the design strength of concrete;
-for slabs and vaults with a hole to 2.00m- least 50% of the project;
-for beams opening up to 8.00 m, slabs and vaults with an opening of 2.00 meters to 8.00 meters - a minimum of 70% of the design strength of concrete;
-for bearing structures with an opening larger than 8.00 m - at least 100% of the design strength of the concrete;
Before proceeding to striking, it is necessary to look good state of dolulezhashtata structure on which foot formwork. Began striking pages (formwork side) to be scanned condition of the concrete. Load of striking construction is allowed when the concrete strength has reached 100% of the project or edokazano (in any case only talk) harmless taking loads of the structure at the current strength of the concrete (which is also subject to proof).

Note-classification concrete in compressive strength is dependent on the cylindrical (cylindrical test pieces with a diameter of 15 cm and height 30 cm) or cubes (cubic specimens with edge 15 cm) their strength tested on the 28th day of their maturation under water at + 20 ° C.
     Information was used from: http://www.offroad-bulgaria.com/