Modern concrete pumps are capable of delivering concrete at high speed, they can pump the concrete mixture both horizontally and vertically. And if such brands of concrete pumps as Liebherr, Mecbo, Putzmeister, CIFA or Waitzinger have been successfully working on construction sites in Russia for a long time, then what do domestic manufacturers offer us?
In any type of construction, the most common type of work is the laying of concrete. The need for equipment for supplying concrete mixture to the construction site was, is and will be. And although concrete itself was invented several millennia ago, machines for transferring freshly prepared mixture over long distances appeared relatively recently.
Traditional stationary concrete pumps are manufactured by PJSC "Tuymazinsky Concrete Carrier Plant". The line of equipment is represented by two series of stationary concrete pumps with electric and diesel drives with a capacity of 20 to 70 m 3 / h. The equipment is not a vehicle and can only be moved within the construction site. For medium and small volumes of concrete work, it is worth taking a closer look at the mod. BN 20E or BN20D, issuing 20 m 3 / h at the outlet of the concrete distribution device. The differences between the models can be seen in their letter designation - the letter E indicates the electro-hydraulic type of drive from the 380 V network, and D indicates the hydromechanical drive from the autonomous D-242 engine.
These models also differ in weight: a concrete pump with an engine is 800 kg heavier, otherwise the equipment parameters are identical. The volume of the loading funnel is 0.45 m 3 , the loading height is 1400 mm, the internal diameter of the concrete pipeline is 125 mm. At the outlet, the maximum pressure on the concrete mixture developed by the concrete transport piston corresponds to 6 MPa. The dimensions of the concrete pump do not exceed 5300x1900x2050 mm. Concrete mixture can be supplied along a straight concrete pipeline horizontally to a distance of up to 340 m, and vertically up to 40 m. The hydraulic system is equipped with hydraulic accumulators and European-made concrete transport sleeves. The concrete pumping group is equipped with an S-shaped gate for supplying the concrete mix. Concrete duct links 2600 mm long, providing a total length of 125 m, with 48 couplings, five 90° elbows and one 4 m end flexible hose are standard.
For work with a large volume of concrete work, for example, in the construction of high-rise buildings or in monolithic housing construction, a stationary high-pressure concrete pump mod. BN70D. The performance of this equipment due to the high pressure on the concrete mixture of 11 MPa allows you to supply concrete horizontally to a distance of up to 600 m, and vertically up to 130 m, with a maximum productivity of 70 m 3 / h. The volume of the loading funnel is 0.7 m3, it is equipped with a mixing device, the inner diameter of the concrete pipeline is 123 mm. The main drive system is equipped with a direct-flow hydraulic system in a closed circuit. The main systems of the stationary concrete pump BN 70D, which are responsible for the reliability and stability of the working cycle, are equipped with imported components. So, in addition to the basic autonomous diesel engine D-260, the installation of a Deutz engine, the main block of hydraulic pumps manufactured by Bosch Rexroth, German hydraulic accumulators, Italian elements are also used hydraulics and electrical equipment.
Stationary type concrete pumps in Russia are also manufactured in LLC "Alliance Technologies". The Ryazan enterprise produces four models with a declared capacity from 25 to 80 m 3 / h. junior model of the series BN-25D with an autonomous diesel engine, it is designed to supply concrete mixture to a horizontal distance of up to 400 m, and vertically up to 100 m; brand concrete pump BN-25E- a colleague of the previous one, but powered by an electric motor AIR 180 M 4. Mod. BN-40 has similar parameters, but is equipped only with a diesel engine and boasts a capacity of up to 40 m 3 / h. BN-80 completes the line of concrete pumps produced by the enterprise, provides a capacity of up to 80 m 3 / h and delivers concrete at a distance of up to 500 m and a height of up to 100 m. On all models with a diesel drive, Perkins engines can be installed as an option for a power plant, and on concrete pumps stamps BN-25D and BN-40- Deutz or Hatz engines. The brand of the pump used is PSM-Hydraulics, the piston is Putzmeister or Schwing. The Siemens electronic programmable control unit controls the operation of the concrete pump. The volume of the loading funnel is from 0.4 to 0.6 m 3, the inner diameter of the concrete conduit is 125 mm. Builders will love the ability to equip the concrete pump with concrete-distributing booms, and the autonomous system for flushing the concrete pump and concrete pipeline will make it easy to keep it in working order on the construction site. Small dimensions, not exceeding 5800x1800x2500 for the largest model, make the equipment convenient when moving from site to site.
Russian factory Koluman Rus LLC, founded in Naberezhnye Chelny in 2013 by the Turkish holding Koluman Holding AS, offers five models of truck-mounted concrete pumps with a concrete mix delivery height from 24.5 to 56.2 m, and the delivery range is from 20.5 to 51.2 m. Koluman in terms of productivity can work in the range from 16 to 177 m 3 / h. superstructure JUNJIN Korean production is installed on a super-reliable Mercedes-Benz chassis. Spreading boom on all Z-fold models, front outriggers in X-out and vertical at rear outriggers or swivel on multi-axle models. Concrete pump gates are S-shaped, designed for pumping standard grades of concrete, they are highly reliable in operation. Rexrothhydromatik main hydraulic pump, automatic lubrication system available, centrifugal water pump made of stainless steel. The wireless proportional control panel is already in the basic package, the vibrator is available as an option. The company's decision to use an expensive but proven Mercedes chassis in combination with a low-priced superstructure from Korea justified itself: it turned out to be decent, and, importantly, domestic technology for concrete supply with excellent technical characteristics and an average price, successfully fitting into the price-quality ratio.
Ease of operation of the add-on from JUNJIN is due to the use of a minimum number of electronic components, and the manufacturer himself launches into the series only parts that have been verified by numerous tests and their actual operation. In addition, reliability is added by the fact that Koluman manufactures most of the components of the superstructure in its own production in Turkey using standard components from leading global suppliers. All products manufactured by the Koluman Rus plant in Naberezhnye Chelny are distinguished high quality and occupies its own niche, offering equipment at the turn of the middle and premium class.
Offers concrete pumps on a truck chassis and "Tuymazinsky Concrete Carrier Plant". The model range includes truck-mounted concrete pumps of two main series: TZA with a concrete mix delivery height with short distribution booms of 21 and 32 m and TZA-LIEBHERR with distribution booms of large lengths of 37, 43 and 47 m. Truck-mounted concrete pump ABN 21 (58152A) on the chassis KAMAZ-65115 (6x4, Euro 4) has a compact size, high maneuverability, easy to operate and maintain. In addition, the truck-mounted concrete pump, with its small mass, fully complies with the Technical Regulations of the Customs Union 018/2011 “On the safety of wheeled Vehicle” and passes the weight control posts without violating the above mentioned regulations, as it has a load of less than 8 tons per axle. The autoconcrete pump mod. boasts a similar composition. ABN-37 (58153C) on the KAMAZ-6540 chassis with Liebherr technological equipment - its movement on the roads will be trouble-free. In mod. ABN-32 (58153A) Liebherr components are also used. One of the main advantages of these models, despite the components from Germany, is low price. Concrete pumps of the TZA- Liebherr series of fashions. ABN-43 (58154A) and ABN-47 (58154V) on the KAMAZ chassis are equipped with Liebherr technological equipment with distribution booms from 37 to 47 m.
In addition to the usual TZA concrete pumps, the plant offers a linear concrete pump mod. CityPump with a hydraulic system for unloading and loading cassettes with concrete pipelines, mounted on a KAMAZ-43253 chassis. This concrete pump is designed as standard for concrete delivery up to 120 m and has a capacity of about 80 m 3 /h. The main purpose of the updated model is the laying of concrete in hard-to-reach places in dense urban areas, when working in underground parking lots or tunnels.
As you can see, domestic manufacturers have something to offer Russian builders. Concrete pumping plants made in Russia will find application in the construction of roads, bridges, tunnels, in the construction of buildings and structures from monolithic concrete and reinforced concrete. Without regard to imported vehicles, you can choose a domestic stationary concrete pump or a concrete pump on an automobile chassis, and the chassis can be either a domestic KAMAZ or an imported Mercedes. It is gratifying that in modern construction there is equipment for supplying concrete of our Russian production, greatly facilitating and speeding up construction.
It depends on the dimensions of the site (distance and height of transportation), on the size of individual concrete sections (productivity) and on the properties of the laid concrete (cement content, consistency, grain size, etc.). A concrete pump, which is required to deliver a certain amount of concrete in a given time, must be designed to guarantee the collection of this amount of concrete and its transportation to the place of installation. The supply pressure is greater, the longer the transport pipeline is and the faster the concrete flows through it. It is easy to understand that the driving power of a pump that develops high pressure to transport concrete over a long distance will be greater than that of a plant that only transports concrete over short distances. Only pumps with the same drive power can be compared with each other.
suction
Concrete can only be squeezed out of the pumping cylinder if it has been previously filled with concrete. This filling also requires pressure. Atmospheric pressure (1 bar = 760 torr) forces the concrete into the low pressure tank. The suction piston creates a reduced pressure in the cylinder. Atmospheric pressure "squeezes out" the concrete from the hopper into the cylinder. The pressure difference between atmosphere and vacuum cannot, theoretically, be greater than 1 bar. In the pump, under favorable conditions, it can be 0.8 bar. This means that concrete is fed from the hopper into the cylinder with a maximum of 0.8 bar. Therefore, hard and coarse concrete mixtures are sucked in worse than thin and plastic ones. Optimum suction conditions are ensured when the suction holes have the same cross section as the pump cylinder. The valve (gate) must be designed in such a way that the suction section remains as open as possible, without preventing the inflow of concrete and without changing its direction of movement. Large volumes of concrete require large cylinders and appropriately sized suction ports. The diameters of the suction port and the cylinder determine the maximum grain size of the transported concrete. The simplest rule requires that the diameter of the suction port be at least 3 times the diameter of the largest grain. That is, concrete with a maximum grain of 63 mm assumes a concrete pump with a supply cylinder diameter of at least 180 mm.
Mixer
Modern concrete pumps are equipped with mixers installed in bunkers. The agitator is designed to keep the concrete in a flowing state during pump downtime, it prevents the concrete from settling and destroys the structures that form near the suction holes. However, these mixers are not full-fledged concrete mixers. With the pump switched off and long mixing times, the preparation of concrete with a mixer is very problematic.
Injection
The maximum pressure provided by a concrete pump is determined by its design. Various devices have been developed for different operating conditions. Truck-mounted concrete pumps usually work with short concrete pipelines corresponding to the length of the concrete distributor mast. They require a lower discharge pressure compared to, for example, stationary pumps on construction sites, which must deliver the same volume of concrete to a height of 100 m. For mobile concrete pumps (concrete pumps), as a rule, discharge pressures up to 70 bar are sufficient, including and at high performance. Stationary concrete pumps with concrete delivery over distances up to 1000 m or heights up to 500 m require a pressure of up to 200 bar. Such pressures impose increased structural requirements on all components operating under pressure, such as gate valves, hoses, gearboxes, pipelines, etc. Uninterrupted operation of the pump is only possible if all the specific requirements of a particular construction site are taken into account when choosing it. A plant that is constantly overloaded cannot work efficiently.
| concrete pump model | Productivity, m 3 / hour | Supply pressure, bar | Range of feed up / horizontally, m | Appearance | |
|---|---|---|---|---|---|
Piston stationary concrete pumps |
|||||
| 18 | 70 | 60/200 | |||
| 71/47 | 71/106 | 100/250 | |||
| 65/42 | 56/101 | 100/250 | |||
| 95/57 | 91/152 | 130/350 | |||
| Stationary concrete pump Putzmeister BSA 2109 HP D - rent | 95/57 | 91/152 | 150/400 | ||
| Stationary concrete pump Schwing SP 4800 D - rent | 43-81 | 104-243 | 150/400 | ||
| 102/70 | 150/220 | 180/400 | |||
| Stationary concrete pump Schwing SP 8800 D - rent | 63-116 | 104-243 | 300/800 | ||
| Stationary concrete pump Putzmeister 14000 HP D - rent | 102/70 | 150/220 | 350/1000 | ||
Autoconcrete pump. Domestic, BN-80-20M2;
Productivity 5-65 m 3 / h;
Departure of a distributive arrow of 16 m;
Distribution boom feed height - 19 m;
Boom rotation angle 370 degrees;
Possible range of transportation of the mixture -200 m;
The mobility of the concrete mixture (OK) - 4-14 cm;
Loading height - 1400 m;
Receiving hopper - 0.4 m;
Dimensions: length - 9887 mm.
Calculation 1: norms of time and prices for the supply of concrete mix to the structure with a BN-80-20M2 concrete pump
The operational performance of a concrete pump truck is determined by the formula:
where P T- technical performance of the concrete pump truck;
TO 1 - coefficient of transition from technical productivity to operational, TO 1 = 0,4;
TO 2 - coefficient of reduction in the performance of the concrete pump, taking into account the non-constant mode of supply, TO 2 = 0,65.
5.4. Comparison of options
Table 3 - Comparison of options
Table 4 - Comparison of options
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Naming indicators | ||||
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Mechanical intensity of works | ||||
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Labor intensity of work | ||||
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Duration of work | ||||
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The cost of operating machines |
N mch \u003d \u003d V about / P bet
V about - the volume of concrete work, m 3
P bet - productivity of the concrete paving machine, m 3 / h
We accept the option “supply of concrete mixture by crane” for the supply of concrete mix.
Transportation of concrete mix
Truck mixers SB-92-1A;
The volume of the transported mixture - 4.0 m 3;
Base car KAMAZ -5511;
Mix unloading time - 480 sec;
Dumping height max. - 1950 mm.
Transportation time from the factory to the place of laying 17 min.
Transportation time from the place of laying to the factory 17 min.
The performance of the vehicle with a portioned method of delivering the mixture is determined by the formula:
(6.1)
Qtr - the volume of a portion of the concrete mixture transported in one trip, Qtr \u003d 4 m 3.
cm - shift duration, cm = 8 hours.
Kvr - the coefficient of the use of working time, Kvr \u003d 0.7.
c - the duration of the total cycle of transportation of the concrete mixture, min:
c \u003d s + gpr + in + cpr + o (6.2)
s - loading time of transport at a concrete plant. s \u003d 8 min.
tr - the time of transport with cargo from the plant to the place of laying the mixture tr = 17 min.
in - the time of unloading the concrete mixture, in = 480 sec = 8 min.
ppr - empty run time of transport from the site to the concrete plant. ppr = 17 min.
o - time of cleaning, washing and maintenance of the vehicle, related to one cycle, o = 5 min.
c \u003d 8 + 17 + 8 + 17 + 5 \u003d 55 min.
Then we get the required number of cars
N \u003d P cr / P tr \u003d 32.0 / 25.84 \u003d 1.23 pieces 2 pieces (6.4)
We accept 2 truck mixers.
Calculation of labor costs, machine time, wages for the construction of the foundation
Table 5 - Production costing of work and wages of workers
Designed for supplying freshly prepared concrete with a cone draft of 6...12 cm in horizontal and vertical directions to the place of laying during the construction of structures made of monolithic concrete and reinforced concrete. They are self-propelled mobile concrete transport vehicles, consisting of a basic chassis, a hydraulically driven concrete pump and an articulated boom with a concrete pipeline for distributing the concrete mixture in the boom area in all its spatial positions. Domestic concrete pumps are structurally similar and are equipped with two-cylinder hydraulic piston concrete pumps.
The concrete pump (Fig. 1) consists of two concrete transport cylinders 6, the pistons of which receive synchronous movement in mutually opposite directions from individual working hydraulic cylinders 10, performing alternately the suction stroke of the mixture from the intake funnel 3 and the stroke of pumping it into the concrete pipeline 1. The movement of the pistons is coordinated with the work rotary concrete distributor 2, the rotation of which at a certain angle is carried out using two hydraulic cylinders 12. When in one of the concrete transport cylinders the concrete mixture is sucked from the funnel, in the second one the mixture is pumped into the concrete pipeline through the rotary pipe of the distributor.
Rice. 1. Concrete pump
At the end of the injection stroke, the switchgear changes its position simultaneously with the switching of the stroke of the drive hydraulic cylinders using a servo system.
The receiving funnel is equipped in the upper part with a grate 4, in the lower part - with a paddle stimulator with a drive 11.
Concrete transport cylinders are placed in a housing 5, which has a tank 8 or wash water and communicates with the rod cavities of the concrete transport cylinders. When replacing, the washing water is drained through the drain hole, covered by a lid with a handle 7. The concrete pump is equipped with an electro-hydraulic control unit 9.
The hydraulic drive provides a more uniform movement of the mixture in the concrete pipeline, protects the pump units from overload and allows you to adjust the working pressure and productivity of the machine in a wide range. Two-piston concrete pumps with a hydraulic drive provide a range of regulation of the volumetric flow of 5...65 m 3 /h with a maximum delivery distance of up to 400 m horizontally and up to 80 m vertically.
Technical productivity, m 3 / h, piston concrete pumps
P t = 3600AInk H
where A is the cross-sectional area of the piston, m; l - piston stroke length, m; n is the number of double piston strokes, s -1 ; k n - coefficient of filling with a mixture of a concrete transport cylinder (0.8 ... 0.9).
The main parameter of truck-mounted concrete pumps is the volume flow (capacity) in m 3 / h.
The truck-mounted concrete pump (Fig. 2) delivers ready-mixed concrete in horizontal and vertical directions to the place of installation using a distribution boom 4 with a concrete conduit 9 or an inventory concrete conduit. The distributing boom consists of three articulated sections, the movement of which in the vertical plane is communicated by double-acting hydraulic cylinders 5, 7 and 11. The boom is mounted on a rotary column 3, based on the frame 15 of the chassis 1 through the turntable 2, rotates in plan by 360 ° hydraulic swivel mechanism and has a range of up to 19 m. A hydraulic tank 6 and a water tank 10 are also mounted on the chassis. An articulated sectional concrete conduit 9 attached to the boom ends with a flexible hose 3. The concrete mixture is fed into the intake funnel 14 of the concrete pump 8 from a concrete mixer truck or concrete truck. During operation, the truck-mounted concrete pump rests on outrigger hydraulic supports 16. Truck-mounted concrete pumps have a portable remote control for boom movements, concrete mix flow and turning the concrete pump on and off, which allows the driver to be near the place where the mixture is laid.
Rice. 2. Concrete pump truck
OJSC "Tuymazinsky Concrete Carrier Plant" serially produces the following models concrete pump trucks:
concrete pump truck ABN 65/21 (58150V) on the KamAZ 53215 chassis (6 x 4) with a maximum productivity (supply) of 65 m 3 / h and a height of concrete mixture supply by a concrete distribution boom up to 21 m;
concrete pump truck ABN65/21 (581510) on off-road chassis Ural 4320 (6 x 6) for off-road operation. It has similar technical characteristics with the ABN 65/21 (58150V) model;
concrete pump truck ABN 75/21 on the KamAZ-53215 chassis;
concrete pump truck ABN 75/32 (581532) on the KamAZ-53229 (6 x 6) chassis with a maximum capacity of 75 m 3 / h and a concrete mix delivery height of up to 32 m. a centrifugal pump was installed by water pressure, air cleaning of concrete pipelines with a wad was used after work was completed, a hydraulic drive with closed circulation of the working fluid was installed, which made it possible to significantly reduce its volume;
concrete pump trucks ABN 75/33 and ABN 75/37, which are produced jointly with the Italian company "Antonelli", specializing in the production of concrete distribution booms.
Truck-mounted concrete pumps are operated at a temperature of - 5...+ 40 °C. The technical characteristics of concrete pumps of JSC "TZA" are given in Table. one.
Table 1. Technical characteristics of concrete pumps of JSC "TZA"
Parameters |
Model |
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ABN 65/21 (58150V) |
ABN 75/32 (581532) |
ABN 75/33 |
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The maximum height of the concrete mixture supply by the concrete distribution boom from the ground level, m |
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type of drive |
Hydraulic |
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Loading height, mm |
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Angle of rotation of the concrete distribution boom, degrees: |
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in the vertical plane |
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in the horizontal plane |
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Loading funnel capacity, m 3 |
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Chassis type |
KAMAZ-53215 |
KAMAZ-53229 |
KAMAZ-53229 |
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Overall dimensions, m |
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Gross weight of the concrete pump, kg, no more |
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including distributed to the front axle |
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on the axle of the rear bogie |
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OJSC "Tuymazinsky Concrete Carrier Plant" produces two models stationary concrete pumps:
concrete pump SB-207 with electro-hydraulic drive and 380 V mains supply;
concrete pump SB-207A with a hydromechanical drive from an autonomous D-144 diesel engine with a power of 36 kW, which eliminates the need for power supply.
Concrete pumps are designed to receive freshly prepared concrete with a draft of a standard cone of 6 ... 12 cm from truck mixers or special loading devices and supply it through a concrete pipeline to the place of installation. They are used in the construction of buildings and structures made of monolithic concrete or reinforced concrete, in the performance of finishing work.
Pump units of concrete pumps SB-207 and SB-207A are similar. Concrete pumps are mounted on single-axle chassis and transported from site to site in a trailer to a truck. The chassis is equipped with four support legs, on which the concrete pumps rely during operation, and a towing device. High mobility and relatively small dimensions allow efficient use of concrete pumps in cramped conditions. The operation of concrete pumps is controlled from a stationary control panel.
Concrete pumps are operated at a temperature of - 5...+ 40°C.
The technical characteristics of stationary concrete pumps are presented in Table. 2.
Table 2. Technical characteristics of stationary concrete pumps
Parameters |
Model |
|
SB-207 |
SB-207A |
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Maximum technical productivity at the outlet of the concrete distributor, m 3 / h |
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type of drive |
ElectrohydraulicFrom the mains 380 V, 30 W |
Hydromechanical transmission from an autonomous engine D-144 |
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Installed power, kW, no more |
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Internal diameter of the concrete pipeline, mm |
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Loading height, mm |
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The volume of the loading funnel, m 3 |
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Maximum pressure on the concrete mixture by the piston at the outlet of the switchgear, MPa |
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Maximum aggregate size, mm |
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Overall dimensions, m |
3.575x1.86x2.05 |
3.575x1.86x2.05 |
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Mass of technological equipment, kg |
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Gross weight distribution, kg: |
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On the front axle |
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On the axle of the rear bogie |
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To increase the functionality and efficiency of stationary concrete pumps, a circular concrete distributor BRK-10 is used, which is designed to receive freshly prepared concrete from concrete pumps and place it in structures made of monolithic concrete and reinforced concrete. The most effective concrete distributor is used when concreting large open areas: foundations of structures (zero cycle), road surfaces, airfields, hydraulic structures, floors, floors and roofs of buildings, etc.
The use of the BKR-10 concrete distributor makes it possible to realize the maximum horizontal range of the concrete pump and increase labor productivity by reducing the number of rearrangements.
Below is the technical characteristics of the BKR-10 circular concrete distributor:
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Maximum boom reach, m |
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Angle of rotation of the boom in the horizontal plane, degrees |
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The area of overlapping (service) of the working platform with a concrete distributor, m 2 |
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Internal diameter of the concrete pipeline, mm |
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Maximum aggregate size, mm |
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Overall dimensions, m: |
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in working position |
12.37 x 2.32 x 1.97 |
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in transport position |
7.2 x 1.685 x 1.61 |
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Weight, kg: |
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constructive without ballast |
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ballast |
concrete pump truck(fig. 7.3) is a hydraulic concrete pump mounted on a vehicle and equipped with a sectional hydraulically controlled manipulation boom. Along the boom, which usually consists of three articulated sections, a concrete pipeline connected to the concrete pump passes, ending with a sleeve.
The concrete mixture from the mixer truck is fed into the receiving hopper (funnel) of the concrete pump, from where it is directed to two concrete transport cylinders, the pistons of which receive synchronous movement in mutually opposite directions from individual working hydraulic cylinders, alternately sucking the mixture from the funnel and forcing it into the concrete conduit. The synchronous operation of the hydraulic cylinders is provided by a valve-distributing device, which includes vertical and horizontal shutters to block the discharge and inlet openings, respectively, in the extreme positions of the pistons.
Rice. 7.3. ABN-65/21 concrete pump
1 - car KamAZ-53215; 2 - power take-off box; 3 - outrigger; 4 - hydraulic tank; 5 - distribution boom; 6 - water tank; 7 - receiving box; 8 – hydraulic cylinder of outriggers; 9 - frame
The technical characteristics of concrete pumps are given in table. 7.4 and 7.5. Table 7.4
Technical characteristics of domestic concrete pumps
Table 7.5
Technical characteristics of truck-mounted concrete pumps of foreign companies
Main parameter concrete pump truck is volumetric feed(productivity) in m 3 / h. In the technical characteristics of the machine, the design and construction (maximum) performance P max is given.
Operating hourly productivity concrete pump truck P e is defined as
P e \u003d P max K and, (7.5)
where K and - the coefficient of use of the maximum supply of a concrete pump (K and = 0.4 ... 0.6).
Concrete pump truck (ABN) is structurally adapted to work in a set with concrete mixer trucks (ABS), the number of which N ABC is:
N ABC = P ABN / P ABS, (7.6)
where P ABN is the operating hourly productivity of the concrete pump, m 3 / h; P ABS - the same, concrete mixer truck.
The average hourly operational productivity of the concrete mixer P ABS is equal to:
P ABS \u003d 60 q K in / T c, (7.7)
where q is the volume of the mixture transported in one run of the mixer truck, m 3;
T c - the duration of the cycle of the concrete mixer truck, min.:
T c \u003d t 1 + t 2 + t 3 + t 4 + t 5, (7.8)
where t 1 is the loading time of the concrete mixture; t 2 - the duration of the flight in the cargo direction; t 3 - the duration of processing of the concrete mixture delivered in one run, min; t 4 - the duration of the trip empty, min; t 5 - time for cleaning, washing, maintenance of the machine, related to one trip, min.
It is assumed that
T 2 \u003d t 4 \u003d 60L / v CP, (7.9)
where L is the average distance of concrete mix transportation, km; v cf - the average speed of the car (loaded - 30 km / h; empty - 50 km / h).
The processing time of the concrete mixture delivered in one run t 3 can be calculated by the formula
T 3 \u003d 60 q K n / P e, (7.10)
where q is the volume of concrete mix transported by a concrete mixer truck in one trip, m 3; K n - the coefficient of uneven supply of the concrete mixture (K n \u003d 1.15 ... 1.25); P e - operational performance of the concrete pump, m 3 / h.
7.4. Concrete Compaction Equipment
Various types of vibrators are used for compaction and leveling of the concrete mixture during its laying, as well as for unloading materials from bins, buckets and vehicles.
vibrators, used to compact the concrete mixture, are classified (Table 7.6) according to the method of influencing the concrete mixture, the type of energy used, the method of excitation of vibrations and the range of vibration parameters (frequency and amplitude of vibrations).
Table 7.6
Classification scheme for vibrators for concrete compaction
| Vibrators | By way Impact For concrete mix | deep (internal) |
| superficial |
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| outdoor |
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| By type used Energy | electromechanical |
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| electromagnetic |
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| pneumatic |
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| hydraulic |
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| By way arousal fluctuations | oscillatory (reciprocating) |
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| rotational (unbalanced) |
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| According to the frequency range and amplitude of vibrations | low-frequency (3500 min -1; 3 mm) |
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| midrange (3500…9000 min -1 ; 1.5 mm) |
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| high frequency (10000…20000 min -1; 1…0.1 mm) |
In construction, electric and pneumatic deep and surface vibrators with circular (rotational) vibrations are most widely used. Compared to electric pneumatic vibrators, they are used less often, since they require a compressor unit and emit noise during operation. Electric vibrators in the model index have the letter IV, pneumatic - VP. The digital part of the index means the model number, the letters after the digital index - the ordinal modernization of the vibrator. Each vibrator is characterized by driving force, static moments of unbalances, frequency and amplitude of oscillations.
Internal vibrators used for compacting concrete mix in reinforced structures. The diameter of the working part of the vibrator should be 1.5 times less than the distance between the reinforcement bars. Deep electromechanical vibrators are divided into vibrators with a built-in electric motor (maces) and vibrators with an external electric motor and a flexible shaft.
Deep manual unbalanced electromechanical vibrators-maces(Fig. 7.4, a) with a built-in electric motor have a single design scheme. The body of the vibrator head is a hermetically sealed steel cylinder, inside of which there is an electric motor and an unbalanced vibration mechanism. A cover with a tubular rod is screwed on top of the body, cut into two parts in order to install a rubber shock absorber that protects the worker's hands from the harmful effects of vibration. Power is supplied to the motor by an electric cable located in a tubular rod.
Rice. 7.4. vibrators
1 - body; 2 - platform; 3 - formwork
Internal vibrator with remote motor and flexible shaft(Fig. 7.4, b) consists of an asynchronous electric motor with a squirrel-cage rotor, a flexible shaft and replaceable vibration exciters. The electric motor with external air cooling is mounted on a trough-shaped stand. From the electric motor shaft, the rotation is transmitted by the coupling to the intermediate shaft installed in the bearings of the tip housing.
Surface (site) vibrators transmit vibrations to the laid mass of concrete through a trough-shaped rectangular slab-platform (Fig. 7.4, c). They are used when concreting ceilings, floors, vaults and other structures with a thickness of not more than 0.25 m. vibration exciters surface vibrators are used unbalanced vibrators general purpose with circular vibrations and built-in electric motor. Surface vibrators also include vibrolaths, having a more elongated base, on which several vibration exciters are installed, interconnected by shafts.
Outdoor vibrators (Fig. 7.4, d) transmit the vibrations of the compacted mixture through the formwork or form, to which they are attached from the outside with the help of special fastening devices. Such vibrators are used in the concreting of thin densely reinforced structures, the manufacture of prefabricated reinforced concrete elements in the factory, and to stimulate the unloading of loose and viscous materials.
The technical characteristics of deep and surface vibrators are given in Table. 7.7.
Table 7.7
Technical characteristics of deep and surface vibrators
| Indicator | Vibrating heads | Flexible Shaft Vibrators | Over- vibrator IV-91A |
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| IV- | IV-102A | IV-103 | IV- | IV- | IV- | IV- |
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| Dimensions of the working body: | area 550×950 mm |
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| diameter, mm | 50 | 75 | 114 | 28 | 38 | 76 | 51 |
|
| length, mm | 412 | 440 | 480 | 410 | 410 | 430 | 410 |
|
| Oscillation frequency, Hz | 200 | 200 | 100 | 330 | 330 | 210 | 285 | 50 |
| power, kWt | 0,27 | 0,8 | 0,8 | 0,75 | 0,75 | 1,0 | 0,75 | 0,8 |
| Weight, kg | 10 | 15 | 24 | 5,5 | 11 | 11 | 11 | 46 |
vibrator type are prescribed depending on the nature of the structure to be concreted and the degree of its reinforcement, as well as the laying conditions and the consistency of the concrete mixture. The laying and compaction of the concrete mixture is carried out in layers, the thickness of which must be consistent with the characteristics of the vibrator. So the thickness of the layer compacted by manual deep vibrators should not exceed 1.25 of the length of the working body (vibrator tip). For the IV-91A surface vibrator, the maximum layer thickness with single-row reinforcement is 25 cm; with a double - 12 cm.
Technical Performance deep vibrator is determined by the formula
P t \u003d 3600 π R 2 H k p / (t 1 + t 2), (7.11)
where R = (5…6)D n – vibrator action radius, m; D n - diameter of the working body of the vibrator, m; H is the thickness of the worked layer of the laid concrete mixture, m; k p - coefficient of overlap of vibration zones (k p \u003d 0.7); t 1 - the optimal duration of vibration in one position, s (Table 7.8); t 2 is the time of moving the vibrator from one position to another, s (t 2 = 5…15 s). In technological calculations, it is recommended that the layer thickness H be taken equal to:
H \u003d L P - (0.05 ... 0.1), (7.12)
where L P is the length of the working body of the vibrator, m.
The technical performance of the surface vibrator is
P t \u003d F δ k p / (t 1 + t 2), (7.13)
where F is the working area of the vibrator base m 2 (for the IV-91A vibrator F = 0.55 × 0.95 ≈ 0.5 m 2); δ is the thickness of the structure, m (should not exceed 0.25 m); k p - overlap coefficient (k p \u003d 0.9); t 1 , t 2 - see above.
Table 7.8
Vibration duration of the concrete mix at one vibrator station, s
| Mobility of concrete mix, m | Concrete mix processing time, s, vibrator |
|
| deep | superficial |
|
| 0 | 40 | 50 |
| 1…3 | 35…30 | 45…36 |
| 4…8 | 29…25 | 36…30 |
| 9…12 | 24…20 | 29…25 |
| 13…15 | 19…17 | 24…20 |
Operating performance vibrator P e, m 3 / h, is equal to
P e \u003d K in P t, (7.14)
where Кв is the coefficient of vibrator utilization in terms of time during the shift, Кв = 0.75…0.85.
When choosing the type of vibrator, it is necessary to ensure the fulfillment of the following condition:
P e ≥ N star / H vr, (7.15)
Where N vr - the rate of labor costs per 1 m 3 of laid concrete according to (ENiR-4-1), man-hour; N zv - the number of link concrete workers, pers.
7.5. Control questions to section 7
1. From what components are concrete mixtures and mortars prepared? What types of machines and equipment are used for this?
2. Give a classification of mixers and name the preferred objects of their application?
3. Name the main types of cyclic mixers, describe their design and principle of operation.
4. Name the main types and applications of continuous mixers. Describe their device and principle of operation.
5. Name the types of mixing plants and give their classification. What are the features of high-altitude and two-stage technological schemes? How is the capacity of a concrete mixing plant determined?
6. How are dispensers classified? How do they differ in functional and constructive features? Which components are dosed and under what conditions are they used?
7. How does a batch weigher work and how does it work? Explain the diagrams of the device and the principle of operation of continuous dispensers.
8. What tasks are solved by using automatic control systems for equipment and installations for the preparation of concrete mixtures and mortars? What is the element base of modern automatic technological systems? Give a classification of automatic systems according to the algorithm of control and assignment.
9. Name the composition of concrete pumping plants. What are the types of concrete pumps? What is the purpose and device of concrete pumps. How is the performance of a concrete pump truck determined?
10. In what ways is the concrete mixture compacted? Give a classification of vibrators for compacting concrete mixtures. What are the principles of their operation and security measures in their application?
11. What are internal vibrators intended for, how are they arranged and how do they work? How to choose the type of internal vibrator and determine its performance?
12. What are surface vibrators intended for, how are they arranged and how do they work? How is the performance of surface vibrators determined?
8. Machinery for track work
8.1. Classification and indexing of track machines
The work performed during the construction of the upper structure of the railway track is commonly called track work. Track works during the construction of new railways, second tracks, station and sidings, the following processes include: assembly of track elements (track links, turnout blocks), track laying, track ballasting, straightening and finishing of the track. All these processes are carried out with the help of sets of track machines.
Track machines they are classified according to their purpose, the possibility of movement, the principle of operation, the type of drive, the type of running equipment, depending on the presence of a power plant, the method of movement in working condition (Table 8.1).
Table 8.1
Classification of track machines in the construction of railways
| classification sign | Varieties Machines |
| Purpose cars | to assemble track links |
| for assembling turnout blocks |
|
| for laying track and turnouts |
|
| for track ballasting |
|
| for ballast compaction and track straightening |
|
| transport and handling facilities |
|
| Ability to move | heavy (non-removable) machines |
| light (removable) machines |
|
| Principle actions | cyclic action |
| continuous action |
|
| drive | electric |
| hydraulic |
|
| pneumatic |
|
| mechanical |
|
| A type running equipment | on the railroad |
| on caterpillar tracks |
|
| on the combined (pneumo-railway) |
|
| Power supply method | autonomous (with power plant) |
| non-autonomous (without power plant) |
|
| Way movement in working order | self-propelled |
| semitrailer |
|
| trailed |
Track machine indexes consist of alphabetic and numeric parts. The letters before the numeric index are usually an abbreviation of the main purpose of the machine. The digital index most often contains the technical characteristics of the machine (capacity, load capacity, structure length, etc.), and the letters after the digital index contain serial modernization
8.2. Machinery and equipment for track assembly and laying
8.2.1. Machines for assembling rail links
Machines for assembling rail links are divided into two groups: semi-automatic link assembly lines and mechanized link assembly stands. During the construction of new railways with a volume of work of more than 70 km / year, links with wooden sleepers are assembled on production lines PPZL-650 (PPZL-500), ZLKh-800, and with reinforced concrete sleepers - on ZLKh-500, ZLZh-650 (CHPZ- 500B), PZL-850. The technical characteristics of these lines are given in Table. 8.1.
Table 8.1
Technical characteristics of link assembly lines
| Parameter | PPZL- | PPZL- | ZLH- | ZLH- | ZLZh- | PZL- |
| Productivity, m / shift | 450 | 585 | 1000 | 500 | 650 | 850 |
| Binding type | crutch | terminal bolt |
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| Type of sleepers | wooden | reinforced concrete |
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| Rail type | R43 | R43 | R-50 | R-50 | R-50 | R-50 |
| Link length, m | 25; | 25; | 25; 12,5 | 25; 12,5 | 25 | 12,5 |
| Weight, t | 38,2 | 36,5 | 35 | 30 | 31 | 20 |
| Number of service personnel | 20 | 19 | 12 | 29 | – | 35 |
With annual volumes of work less than 70 km, ZS-400, ZS-500 and ZS-500M link assembly stands are used.
Turnout blocks are assembled on three-line mechanized assembly stands.
During the operation of semi-automatic link assembly lines and mechanized stands, the set of machines includes cranes (most often gantry) and electric tools.
8.2.2. Link tracklayers
The rail sections pre-assembled on the base are laid on the track by tracklayers PB-3, PB-3M (Fig. 8.1) or UK-25 (Fig. 8.2).
Rice. 8.1. Tractor gantry tracklayer PB-3M
1 - tractor; 2 - towing device; 3 - rail link;
4 - four-axle platform; 5 - farm; 6 - caterpillar trucks;
7 - traction winch; 8 - lifting winch; 9 - portal;
10 - slinging devices
Rice. 8.2. Laying crane UK-25/9-18
1 - three-axle traction bogie; 2 - frame; 3 - power plant;
4 – platform control panel; 5 - control cabin;
6 – electrical equipment of the platform; 7,13,15 - winches; 8 - cargo traverse; 9 - cargo trolley; 10, 11 - blocks; 12 - arrow; 14 - remote control; 16 - middle transverse beam; 17 - load capacity limiter;
18 - folding beams; 19 - portal carriage; 20 – boom lifting hydraulic cylinders; 21 - portal rack; 22 - fence; 23 - roller conveyor; 24 - electrical equipment on the boom
The technical characteristics of the tracklayers are given in Table. 8.2.
Table 8.2
Technical characteristics of tracklayers
| Indicator | PB- | UK- | UK- | UK- 25/9-18 |
| Annual track laying volume, km | Up to 80 | 80 and over |
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| Length of laid rails with sleepers: wooden | 12,5; | 12,5; | 12,5; | 12,5; |
| reinforced concrete | 12,5; | 12,5 | 12,5; | 12,5; |
| Carrying capacity, t | 18 | 9 | 17 | 18 |
| Productivity, m/h, when laying links with sleepers: wooden | 290 | 800-1000 | 800-1000 | 1000 |
| reinforced concrete | 240 | 350-500 | 350-500 | 750 |
| Weight, t | 31,75 | 78 | 102 | 102 |
Depending on the type of the tracklayer, the links of the rail and sleeper grid are transported in packages on the couplers of four-axle railway platforms equipped with the unified removable equipment USO-4 (tracklayers UK-25 and PB-3M), or on removable trolleys PT-13 (tracklayers PB-3 and PB-3M ). To supply the platform couplers with link packs to the tracklayer, motor diesel platforms MPD or MPD-2, equipped with a roller conveyor, are used.
With dispersed small volumes of work, the links can be transported on automobile trailers-dissolutions.
For transportation of turnout blocks, a special SPS rolling stock of 8 platforms is used, on which turnout blocks are placed in an inclined and horizontal position.
When laying the rail-sleeper grid in curves with a radius of 600 m or less with the UK-25 tracklayer, a MIUZ machine is used to bend the links, which is a hydraulic leveler on a tractor. Docking links produce temporary dockers. Applied in transport construction TsNIIS auto-joiner allows you to accurately maintain the value of the rail gaps.
Turnout blocks are laid with the help of jib railway cranes with a lifting capacity of 10 ... 16 tons (with wooden beams) or with a lifting capacity of 40 ... 50 tons (with reinforced concrete beams). For these purposes, you can also use the laying crane to replace the turnouts UK-25SP, created on the basis of the UK-25/9-18 tracklayer.