FOR THE PRODUCTION OF CONCRETE WORK
PNEVMOBETONIROVANIYA WAY

 
 
UDC 693.546.3
Recommended for publishing the decision section of construction technologies
Scientific - Technical Council of the USSR State TSNIIOMTP.
 
Guidelines for concrete works pnevmobetonirovaniya way. M., 1983. 28 p. (USSR State Committee for Construction. Center. Scientific-issled. Experimental and design. Inst organization, mechanization and technical. Help page-woo. TSNIIOMTP. Bureau of implementation).
At issue guidance technology of production operations in concreting the monolithic thin-walled concrete structures pnevmobetonirovaniya way.
Guidelines prepared by the Bureau of introducing TSNIIOMTP USSR State (MN Marchukov).
 
Central Research
and Design Institute of Experimental
organization, mechanization and technical
help build USSR State
(TSNIIOMTP). Bureau of implementation. 1983
 
M 30207-056-83
 

1. GENERAL PROVISIONS.

 

• Guidelines developed by the development of Chapter 8 of SNiP III-15-76, "Concrete and reinforced concrete structures monolithic" and Chapter II «Guide for the production of concrete work" (TSNIIOMTP, NIIZhB, Moscow, Stroiizdat, 1975 ).
• Guidelines apply to the manufacture of concrete work on the construction of residential, industrial buildings, their reconstruction and repair, as well as in the manufacture of reinforced concrete structures in the factory.
• the production of concrete work pnevmobetonirovaniya way to also comply with the requirements set out in the guidance letter NIIZhB USSR State Committee for "On the design of structures made of fine concrete" ("Bulletin of construction equipment» № 10, 1977), and the "Guide selection of compounds of heavy concrete "(Moscow, Stroiizdat, 1979).
• Concreting reinforced concrete way pnevmobetonirovaniya perform on a pre-designed projects of works, providing maximum use of mechanization and continuity of the process.
• Recommendations are designed to carry out works at an air temperature not lower than +5 ° C

2. FEATURES OF THE METHOD AND SCOPE OF ITS APPLICATION

• Pnevmobetonirovanie method is a kind of air supply application of concrete mixtures, which also includes a way to shotcrete. Unlike other methods pnevmobetonirovaniya shotcrete is that the pipeline material is transported in suspension and are applied with a nozzle on the work surface at a speed of 70-90 m / s is enough plastic concrete mixtures with fine-grained aggregates. Moreover, the mixture can be prepared centrally rastvorobetonnom factory or in a blender unit "Pnevmobeton».
• pnevmobetonirovaniya way has the following advantages:
• retained given water-cement ratio, which is one of the main factors ensuring the required physical and mechanical characteristics of concrete laid;
• decreases significantly dusty work space and reduces the overall fogging;
• loss of components of the "bounce" is reduced to 4-6%;
• labor costs per 1 m3 of concrete laid down by 20-30%;
• qualified service personnel may be lower;
• significantly reduced the accumulation of static electricity that occurs when the motion of a mixture of pipe material.

disadvantage is increased by 30-40% consumption of compressed air.

• This method is most effective in the following cases.

When concreting of reinforced concrete structures:

• surfaces of buildings and structures (domes, shells of positive and negative curvature, etc.);
• capacitive structures of various types and purposes;
• swimming pools;
• thin walls and walls of the rigidity of industrial buildings;
• hyperbolic cooling towers and ventilation;
• columns with flexible and rigid reinforcement;
• thin volume elements in the factory and on site;
• sled trails, etc.

When monolithing precast joints:

• capacitive structures of various types and purposes;
• slabs and coatings industrial buildings and structures;
• collectors large cross-section;
• large-panel buildings;
• wall rigidity frame buildings;
• teams facing channels and so forth;
• precast concrete tunnel lining.

When coating on concrete, reinforced concrete, steel, brick and rock surfaces to make them waterproof and corrosion resistance, as well as the creation of fireproof coatings on steel and wooden surfaces.
2.4. During the reconstruction of production facilities and repair method used pnevmobetonirovaniya:

• to reinforce concrete, reinforced concrete, brick, stone and steel structures such as silos housing elevators, bridge spans, floor slabs, bridges, etc.;
• to repair concrete and reinforced concrete structures such as walls of river locks, dry docks, cooling towers, silos, etc.

2.5. Concrete laid in this manner, a high physical and mechanical properties (density, water resistance, frost resistance, adhesion to different surfaces).
2.6 In respect of all the technological requirements and the correct selection of the mixture provided the following physical and mechanical properties of concrete:
strength - Up to 50 MPa
strength in the axial - Up to 3 MPa
tensile - Up to 6 MPa
the initial modulus
coarseness of sand Mcr = - Within the normal range for
Concrete
- 20% higher than for
conventional concrete
- V-8-10
- Higher than the average
concrete of the same brand

2. APPLIED MATERIALS Concrete mix MIX

Cement

• The binder cements should be used to meet the requirements of GOST 10178-76. Type of cement is selected on the basis of the requirements for normal weight concrete, depending on the conditions of construction and the environment.
• order to reduce the water demand of concrete mix is ??not recommended for use below grade cement M 400, with higher (27%) the normal density of cement paste.
When
• monolithing joints of precast concrete structures should be used widening (VRTS) and straining (NC) cements.

 

Aggregates

• As the filler sand is used, corresponding to GOST 8736-77 and GOST 10268-70.
• Sand for concrete structures, monolithing joints shall be not less than Mach 2.1 and a continuous granulometry.
When the device
• waterproofing coating should be applied to the sands of Mcr = 1,5-2,0.
• In fine sands should be added drop-out rock fines fraction 3-10 mm, obtained by crushing the rock to rubble in an amount up to 50% of the total weight of the filler. The presence of aggregate particles larger than 10 mm is allowed. The optimum content of dropouts should be checked empirically, based on the results of testing samples and the possibility of a mixture of feeder pumpability.
• in sands with more than Mach 2.8 is necessary to add fine sand to reduce the losses of materials to "bounce" and a more dense structure of concrete.
The use of fine sand
• with Mach = 1-1.5 is permissible only after appropriate testing.

 

Supplements
3.10 Additives improve properties of concrete and the structure of hardened cement and provide savings in the acceleration period of hardening. They are used in accordance with the instructions of the "Guidelines for the use of chemical additives in the concrete" (Moscow, Stroiizdat, 1980).

• additives (for example, potash, calcium chloride, water glass, ECO) is reduced to 0.5 hours setting time of concrete mixture, injected directly into the nozzle using a special device doamruyuschego. The use of calcium chloride is allowed only during the concreting of unreinforced structures.
• use of chemical additives during the concreting of structures designed for storage and processing of drinking water, must be approved by the project organization.
• as mineral additives that reduce the consumption of cement in the concrete of fine-grained, ash-use carry-over from burning coal, ground granulated blast-furnace slag, and dumping, ground quartz sand or rock flour.
• additives used in the preparation of concrete, should not adversely affect the skin and respiratory staff.

Water

Water for mixing
• concrete watering and laid concrete meet the requirements of GOST 23732-79.

 
Selection of

 

• composition of fine-grained (sand), concrete is selected in accordance with "Instructions for the preparation of fine-grained (sandy) concrete" SN 488-76 (Moscow: Stroiizdat, 1977).
• When mixing water-cement ratio of concrete, depending on application conditions, such as structural and physico-mechanical properties of the mixture can be 0,40-0,50. In the packed mixture of water-cement ratio is reduced by 10-20%, respectively, due to the compressed air entrainment of the mixing water. The mobility of a mixture of standard immersion cone loading in the feeder should be components of the mixture can be 0,40-0,50. In the packed mixture of water-cement ratio is reduced by 10-20%, respectively, due to the compressed air entrainment of the mixing water. The mobility of a mixture of standard immersion cone loading in the feeder should be 5-8 cm, and packed in a mixture of - 3-5 cm
• calculation of concrete mix on a simplified method under CH produced in the following order:

compressive strength and D / As for the fine (sand), concrete hardening under natural conditions, is determined by the formula:

Rb = 0,4 Rts ( - 0,43);

= + 0,43;

amount of material per 1 m3 of mixture are determined by the formula:

; ;
P = C ; Dm = C ;  
 
Where C, D, Dm, and In - consumption of cement, sand, mineral supplements and water, kg/m3;
C , P , D m, B - the same as in the test team fights;
g - bulk density of sandy concrete mix .
The composition of concrete mix for a given concrete waterproofing and frost should be established empirically. Example of calculation of concrete mix is ??given in Appendix I.

• more accurate calculation of concrete mix made according to the formulas and graphs in Section 7, "Guidelines for the selection of compounds of heavy concrete" (Moscow, Stroiizdat, 1979).
Matched
• of the need to adjust the results of tests of concrete samples, taking into account the actual loss of the components of concrete mix to "bounce". The composition of "rebound" is tentatively taken to be 1:10 (cement: sand) by weight. Fabrication and testing of samples produced by the method described in Section 7.

4. EQUIPMENT

• for transporting fine-grained concrete mixtures and mortars, injection, primary injection and control when tunneling is used setting "Pnevmobeton" - (gunite installation of CO 50PBN).
• Select design settings determine the conditions of production work and the type of construction, the construction of which will be used.
• In all cases, the installation "Pnevmobeton" shall consist of the following:

receiving and mixing device with a compulsory mixer, feeder, vibrating screens with a mesh of 10x10 mm, the material of the pipeline, air piping, nozzles for applying fine-grained mixtures or absorber velocity of the mixture.

• as receiving and mixing device is recommended Sat-97 mortar drum with a capacity of 325 liters or compulsory mixer SB-80 with a capacity of 250 liters, equipped with skip hoist, as well as receiving and mixing device installed UPTZHR-2, 5 designs scream Glavmosstroy.
• as feeder plants "Pnevmobeton" mortar used serial C-683 and C-317B, respectively, the nominal capacity of 2.4 and 6 m3 / h converted to uniflow scheme and additionally equipped with a mixing chamber (Fig. I). The need for conversion driven by the need to pump fine-grained concrete mix mobility of 5-8 cm at the maximum aggregate size of 10 mm.

 
 
 
 

Fig. I. Diagram of the mortar ram
1 - pumping chamber, 2 - a receiving hopper;

• - reference table, 4 - shaker, 5 - WHO-

sultry line; blower box-
tion valve, 7 - mixing chamber, 8 - ma-
arterial line 9 - the working chamber  

 

The material is mounted
• line of the individual bags type III-15 with an inner diameter of 50 or 63 mm (depending on the mode of operation) with special compounds that do not reduce the cross section of the pipeline. The vertical sections of the construction of tall buildings should be collected from the pipeline inventory of steel pipes of the same section.
• nozzle, attached to the end of the pipe material, designed to increase the speed of the mixture to 70-90 m / s and the formation of spray plume. The configuration and geometrical dimensions of the nozzle to the surface. These parameters are determined empirically. The most common types of nozzles are shown in Fig. Two.
• absorber designed to reduce the velocity of the mixture in a pipeline during transportation and installation in the casing or on a horizontal surface mortar or fine concrete mixtures (Fig. 3).

 

Fig. Two. The scheme of the nozzle for the application of concrete mixes
a - on a vertical surface;
b - on a horizontal surface from top to bottom;
in - at monolithing joints
 

Fig. Three. The scheme of the absorber
1 - housing 2 - handle for shifting
absorber, 3 - flange for connection
pipe material, 4 - ski

 

• installation must have a common feeder remote control, receiving and mixing device and vibrating screen, providing for the inclusion of separate mechanisms, including devices for controlling the supply of compressed air. Scheme of the air pipe is shown in Fig. 4. In addition, the unit must be connected audible or visual alarm to the place of the work. Schematic diagrams of installations are shown in Fig. 5, 6 and 7. Plants shown in Fig. 6 and 7 can run on both the starting materials and the finished commodity mix. In this case, they were additionally equipped hopper-loaders. Technical characteristics of the installation "Pnevmobeton" TSNIIOMTP design is given in Appendix 2.

 
 

Fig. 4. Scheme of the air pipe
1 - mortar mixing chamber;
2 - delivery hose with an outer diameter
50 mm, 3 - clip 4 - plug valve, 5 -
gauge of 1.0 MPa, 6 - flange receiver
Compressor
 
 
 
 

Fig. Five. The experimental setup UPTZHR-2, 5, "Pnevmobeton»
1 - stirrer, 2 - Tray 3 - Remote
Control 4 - shaker, 5 - mortar
 
 
 
 
 

Fig. 6. The experimental setup PBTK 6.00.000 "Pnevmobeton»
1 - the water tank, 2 - control unit 3 - vibrating;
4 - compulsory mixer mixing SB-80;
5 - skip hoist, 6 - mortar
 

Fig. 7. Apparatus "Pnevmobeton» 259-2.00.000
1 - cement mixer SB-97, 2 - shaker, 3 - mortar;
4 - skip hoist
 

• The required amount of compressed air at the work unit "Pnevmobeton" is 7-9 m3/min, pressure - up to 0.7 MPa. For compressed air is used most often mobile compressor installation type DC-9M capacity of up to 10 m3/min. In some cases, the great length (60 m) of the material of the pipeline must be used simultaneously two compressor units. Air is fed into the pipeline must be clean and free from impurities oils.
• before beginning work to determine the actual performance and the pressure created by the installation of a compressor at the pressure gauge located on the "Pnevmobeton." Performance calculated from the formula:

P =
where P - performance of the compressor, m3/min;
V - volume of air collector and air pipe, m3;
P - the degree of compression, MPa;
T - time of filling the air collector to the compression ratio R, min.

• Water to install "Pnevmobeton" sum of the water network. The pressure in the network and the diameter inlet pipe should ensure that the water flow of at least 60 l / min. In the absence of piped water supply networks may be from the vessel, equipped with a pump.
Dosage
• water in the preparation of concrete produced with the help of a water meter that came with receiver-mixer.

 

• PRODUCTION WORK

Preparatory work

 

• Prior to work:
• make the selection of fine-grained concrete mix;
• connect installation "Pnevmobeton" to the mains, water mains, alarm and adjust, if necessary, mechanical ventilation of workplaces;
• mount or portable timber bridges, so that the distance between the floor and work surface was 1.2-1.5 m and the height of the stage was equal to 2.0 m;
• link workers to provide the necessary tools and personal protective equipment (see Section 8);
• arrange lighting installation and production work in the dark.
• Before repair work, and when applied to the work surface waterproofing, corrosion-resistant coatings, you must first prepare the surface, ie, cut nodules, clear bumps, bowls, weaknesses, cut the protruding part of the armature and wire, then wash the surface water-air jet and done through holes in the formwork.

Where necessary, should perform additional reinforcement.
Formwork

 

• formwork, concrete used for horizontal surfaces shall comply with the requirements of SNiP III-15-76.
• to establish vertical structures such as lightweight casing, which serves as a reflective screen when applying the mixture in the initial period of concreting.
• as a protective screen can be used rolled steel mesh with a mesh of not more than 3x3 mm and wire thickness not less than 1 mm, and woven materials (burlap, fiberglass, etc.).
• not permitted in the mold slit width of 5 mm.
• To reduce the grip of wooden formwork with concrete, the surface before applying the concrete mixture is not recommended to wet with water.
You may not
• stud wooden formwork rolled roofing materials (tar paper, roofing material, polymeric films, etc.), as it makes the first coat of concrete mix.

 
Reinforcement of

 

• the production of reinforcing steel work should be guided by the requirements of SNiP III-15-76, and the following provisions:
• clear distance between reinforcing bars shall be not less than 90 mm at a thickness of 80 mm constructions;
• design thickness greater than 80 mm clear distance between the rods must be at least 135 mm;
• minimum distance between reinforcing bars and formwork is assumed to be 15 mm;
• structures with a thickness greater than 200 mm of vertical reinforcing structures is recommended in two stages;
• nodes knitting wire must not extend beyond a shadow of rebars;
• splicing of rebars produced in a plane parallel to the direction of the pneumatic feed mixture.

 

monolithing joints

• Depending on the design of the junction are two ways to monolithing vertical joints.

In the first case, the end of the discharge hose with an inner diameter of 38 or 50 mm lowered into the joint to its full depth and extent of joint filling mixture is gradually removed from the oral delivery hose joint. The distance between the end of the sleeve and packed with a mixture should be 40-60 cm diameter orifice nozzle when using sleeves 50 mm in diameter should be equal to 40 mm.
In the second case, the joints of the concrete mixture monolithing layers are applied on the side, using a nozzle of rectangular cross section.
5.11. Horizontal joints zamonolichivayut fiberwise application of concrete from the top down, using a nozzle with an orifice diameter of 40 mm. Each layer should have a thickness of 20-40 mm.

Concreting reinforced concrete structures

• Concreting way pnevmobetonirovaniya structures should be performed at a thickness of structures up to 150 mm. In some cases, the relevant feasibility study can be manufactured in such a way thicker structures.
When concreting
• particularly complex structures should first develop technology for production work on the fragment, manufactured in full size.
In the production of works
• pnevmobetonirovaniya way to observe the following requirements:
• nozzle when applied to the concrete mix horizontal and vertical surfaces are perpendicular to them;
• permitted deviation of the nozzle at a slight angle when filling the space with a diameter of reinforcing bars bolee16 mm;
• concrete mixture is applied to vertical surfaces from the bottom up;
• carried out by applying a mixture of vertical translational movement of the nozzle (Fig. 8);

 
 
 

Fig. Eight. The scheme of moving the nozzle for application of concrete
mixture on a work surface

• nozzle should be at 0.7-1.2 m from the working surface to minimize the "bounce" and to prevent premature fouling reinforcement concrete mixture;
• once applied layer thickness should not exceed 15 mm - when applied to the horizontal (bottom to top) surface, 25 mm - when applied to vertical surfaces, 50 mm - when applying horizontal (downward) surface, which is determined by the temperature and humidity conditions of the environment, as well as the rheological characteristics of the mixture;
• when the signs of sliding into the concrete mix to reduce the thickness of the deposited layer;
• when applying the first layer on the casing, or hardened concrete, use a fine-grained concrete mix, prepared on the fine sand, which reduces the loss of materials to "bounce", and the thickness of this layer should not exceed 10 mm;
• each subsequent layer is applied after the previous setting;
• during outages before applying the next layer of the surface of the previously laid concrete should be wet.
• large surfaces is divided into zahvatki and arrange construction joints .. Damage layers are reduced to "wedge" of width 250-300 mm, provided that the total thickness of the layers does not exceed 80 mm. For greater thicknesses, respectively, the width of the wedge increases.
• For a flat surface after the last seizure caused by an additional layer of concrete finished surface application of the solution on the fine sand, which is immediately smoothed.

 

device is waterproof, corrosion-resistant coatings and other

When the device
• waterproofing, corrosion resistant, fire retardant coatings, etc. in addition to the requirements of Section 5.14 shall be complied with the following conditions: the thickness of applied layer should not exceed 10 mm, the total number of layers is determined by the project, but it can not be less than two, the second and subsequent layers are applied after the previous setting, for the application used a nozzle with a diameter of 26-320 mm orifice, regardless of the position of the working surface as an aggregate concrete used sand from Mcr = 1.5-2; consumption of cement shall be not less than 600 kg / m3.

 

repair and strengthening of structures

• Repair and strengthening of structures perform under Section 5.14 with the following additional guidance: working surface shall be thoroughly cleaned in accordance with the draft prepared by the project organization based on the survey.

 

Transportation fine-grained concrete mixtures and solutions

To lay
• solutions and concrete in the formwork or to the horizontal surface at the end of the pipe material installed damper velocity and motion of the mixture.
• Legislative mixture compacted in the usual way, using the vibration.

 

• STAFF AND RESPONSIBILITIES

• Link, serving the installation of "Pnevmobeton" shall consist of four people: plasterers IV Res. - 2 V driver bit. - 1, a maintenance worker II Res. - 1.

When preparing a mixture of raw materials to the worksite of the link further comprise a part-time worker II category.

• entire staff before any work has to pass the relevant theoretical and practical training.
• Darby IV level required:
• clean work surface from dirt, foreign material and moisture;
• keep the nozzle perpendicular to the work surface and at an optimum distance from it;
• apply a layer of desired thickness uniformly across the surface;
• when working with reinforced structures to prevent premature fouling of rebar concrete mixture;
• care for hardening concrete;
• adjusted in the production process and the mobility of the concrete mix plant productivity;
• promptly remove the "rebound»;
• to signal the beginning and end of work (no signal plasterer supply of air, water or concrete in the pipeline are prohibited).
• Motorman V level required:
• provide installation services;
• follow the correct dosage of the mixture, and mixing water (in the case of mixing at the worksite);
• ensure continued mobility of the mixture while loading the hopper feeder;
• to adjust the installation to ensure a uniform spray, and the expiration of the concrete mix at the nozzle exit;
• monitor signals plasterers;
• provide overall guidance link.
• maintenance worker II category must:
• to make acceptance of mixture with the car;
• loaded skip hoist bucket of ready mix or dry ingredients with the required dose;
• assist the engineer in the care of the installation;
• assist plasterers in the relocation of the pipeline material.

• CARE AND QUALITY CONTROL CONCRETE

 

• Enabling temperature and moisture conditions for curing of concrete is determined protect it from exposure to wind, direct sunlight and constant moisture.
• Concrete surface sheltered vlagozaderzhivayuschimi materials (burlap, sawdust, etc.) is recommended to periodically watered.
• surfaces of concrete, which are then not subject to union with the other structures with concrete or mortar joints should be covered film-forming compounds, or protective seal.
• hardening concrete must be protected from impact, shock and other mechanical influences.
• layer of concrete caused pnevmobetonirovaniya way, and being in contact with running water, must be protected from its effects in the first two or three days (depending on the intensity of flow).
• During the production of works on construction pnevmobetonirovaniyu laboratory staff constantly monitor: particle size distribution of aggregates and their compliance with state standards, the activity of cements, ready for concreting sections (surface preparation, installation reinforcement); correct dosing and mixing (twice per shift), the thickness of layers applied (not less frequently than every 100 m2 of surface), irrigation timing, physical and mechanical properties of concrete (for every 50 m3 of poured concrete).
• control samples (cubes, prisms, cylinders) are cut from specially concreted slabs, with dimensions of at least 50h50h12 cm or directly from the structures. From the extreme parts of the plate with the disturbed samples are not cut.
• To simplify the determination of strength of poured concrete applied during compression technique developed by the institute "Orgenergostroy," but it is introduced into the conversion factor K

conversion factor determined by the results of joint tests of at least 36 standard-size cubes 100h100h100 i36 mm specimens cut from plates made pnevmobetonirovaniya way.
Standard samples and experimental plates are made from a mixture of both of the same composition and mobility.
The conversion factor is calculated by the formula:

K = ,
where Rszh - compressive strength of test samples;
R - compressive strength of standard samples.
The value of conversion factor is in the range 1,1-1,2.

• SAFETY

 

• the production of works with the installation "Pnevmobeton" should be guided by SNiP II-4-80 "Safety in Construction" and "Technical description and operating manual installation" Pnevmobeton "TSNIIOMTP construction (project 259 - 2.00.000T0).
• not use a faulty installation, and repair various defects during its operation. Troubleshoot the working chamber, the outlet valve box valve, mixing chamber, the material and air piping and nozzles can only be received after the termination of the compressed air into the mixing chamber and the total discharge of residual pressure over the whole path from the inlet valve to the nozzle.
• At the time of the flare control, and the washing nozzle is installed needs to be fixed to an immovable object. It is strictly forbidden to direct the nozzle towards the people.
• safety valve of mortar should be adjusted according to the gauge pressure of 1.0 MPa maximum. Working with the corked hole of the valve or no valve is strictly prohibited.
• With increasing air pressure in the compressor air collector in excess of the allowable grouting should be shut down, reset all the pressure in the system and identify the causes of increasing pressure in the pipe material.
• Before starting material molded to the pipeline pressure of 1.5 MPa. The pipeline have so that it does not interfere with the movement and not exposed to damage.
• Individual sleeves should be fixed to each other in a special flange bolt-wedge connections supplied by the manufacturer. The dimensions of fittings shall conform to the diameter and wall thickness of the sleeve. Inner ring compounds and pressure hoses as they wear must be replaced in a timely manner.
• to work with a deficiency of air, causing the pipe plug can be formed, is strictly prohibited.
• Power and lighting wiring must be enclosed in conduit to prevent possible damage.
At
• lights, wear protective shields of toughened glass.
• Permanent and mobile scaffolds must have a continuous solid floor with a railing and stairs with railings.
• During the plasterer must wear protective goggles or face shields with a transparent screen, and respirators when working inside the premises where it is impossible to arrange ventilation. The rest of the staff, provide protective clothing in accordance with existing regulations.
• presence of unauthorized persons in the area of ??the plant "Pnevmobeton" is prohibited.

 
 

Appendix 1

SELECTION OF THE SAMPLE fine concrete
required to select the composition of fine-grained concrete M 300 in the uncured Portland cement M 400 and the average particle size of sand with a bulk volume of 1,500 kg/m3. The mobility of the concrete 5 cm

According to the formula
• find the required C / B

= + 0,43 = + 0,43 = 2,30 (B / D = 0,43).

Calculate the amount of material
• on a test batch of 7 liters. Take at the same time-averaged flow rate 230 kg/m3 and a flow of sand m3/m3.

 

In i = = 1.61 l;
C i = 1,61 x2, 30 = 3.70 kg;
P i = = 10,5 kg;

Prepare a trial batch
• determine the mobility of the concrete mix. If mobility is not sufficient, an additive injected cement and water to 0.1 of their content in a test batch to achieve the required mobility (mobility with excess sand is added).

need to enter a single supplement.
The content of the materials in the adjusted trial batch:
In i = 1,61 + 0,16 = 1,77 l;
C i = 3.70 + 0.37 = 4.07 kg;
P i = 10,5 kg;
The composition of concrete mix by weight:
U: P: B = 1: 2,58: 0,43.

Determine the volumetric mass
• (gp.b.s.) in a measuring cylinder 1-liter, rigidly fixed to the vibrating table, and seal it with a 5.

Bulk density turned gp.b.s. = 2200 kg/m3.
Consumption of materials, kg/m3:

C = = 548;
n = 549 = 1413;
In = 549 = 238.
Prepare control samples - cubes that are experiencing after steaming or after 28 days of normal hardening in accordance with GOST 10180-74. The strength of the samples should be evaluated according to GOST 13105-77 and comply with a given brand. If the concrete strength has turned more or less a given, conduct adjustment of D / V.
Appendix 2

characteristics of the unit "PNEVMOBETON»
TSNIIOMTP CONSTRUCTION
capacity, m3 / h:
fine-grained mobility in the concrete mix 9.11 - 3
However, 6-7 2
Operating pressure in the pressure pipe, MPa - 0.7 (7)
Range of feed mixtures for spraying, m
on - 60
on - 30
Range of feed solution during transportation, m
Horizontal - 150
on - 60
The highest water consumption, - 60
The greatest flow of compressed air, - 9
The greatest pressure of compressed air, MPa - (0.7) 7
Mortar, - 0-684
number - 1
diameter of the plunger - 90
move the plunger, - 90
speed of rotation of the crankshaft, rad / s - 9 (165)
motor, the type of -A02-41-4
Power - 5,5
voltage, - 220/380
rotational speed, rad / s -153 (1460)
Mortar, - SAT-97
motor, - 4A112M
Power - 5,5
voltage, - 220/380
rotational speed, rad / s -152 (1450)
Vibrator - IV-20
Power - 0,4
voltage, - 220
speed of rad / s -292 (2800)
Installed capacity, - 9,9
Dimensions,
- 3670
- 2775
- 3410
Weight - 2810

 

 

 

 

 

CONTENTS
 
General
Features of the method and its application area
The materials used and the selection of concrete mix
Equipment
Production work
Service personnel and their responsibilities
Curing and quality control
Safety
Applications.

• Sample selection of fine concrete
• Specification unit "Pnevmobeton" TSNIIOMTP designs