In some cases, the construction of the object is impossible without the use of this equipment. For example, when installing structures in cramped conditions or during the pouring of densely reinforced structures.

The most popular types of concrete pumps today are techniques with a mechanical or hydraulic type of drive. Models are piston, rotary and screw. All of them have their pros and cons, so the choice of technique should be approached especially carefully.

There are different types of concrete pumps, each of which has its own features and scope of application. For example, there are not only stationary, but also auto concrete pumps.

How the concrete pump works

In most cases, the principle of operation of the concrete pump will be as follows:

• Due to the movements of the hydraulic cylinders, the mortar enters the inside of the transport cylinder from the receiving hopper.
• The mixture is pumped into the concrete conveyor.
• The pumping speed is regulated by using different amounts of oil (oil-hydraulic models).

It should be noted that the device and operation of the concrete pump are not always the same. Some types of equipment are designed for periodic delivery of concrete, while others – for continuous pouring. Each of the options has found its application in construction:

Continuous mix delivery is needed to fill large structures in their entirety. As a rule, rotary models are used for this purpose.

Intermittent pouring will be an advantage if it is necessary to pump concrete into small segments of formwork of different structures. For this purpose, piston-type equipment is best suited.

The principle of operation of the autoconcrete pump should be considered separately, since it differs from that of stationary equipment:

• The concrete mixture is unloaded from the mixer of the concrete truck into the receiving hopper.
• The pumping station pumps the solution into the system.
• The mortar is conveyed through pressurized pipes.
• The mixture is subsequently unloaded at the end point.

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Pouring the concrete mixture into the formwork is not the end of concrete work, as previously written poured concrete requires further care, to acquire the required strength in a certain period of time. Increase in the strength of concrete at the initial stages is fast and concrete prepared on Portland cement already on 7 – 10 days after pouring, gaining 60-70% of its design strength, which comes on 28 days. After that, the rate of strength gain slows down. Under optimal conditions of hardening concrete is best to gain strength at t=20 C and humidity of at least 80%) and it is especially important to maintain such conditions during the first 3-5 days. For more information about concrete care and its necessity, please see “Why Concrete Care?”.

Uncracking

To disassembly work can begin after the concrete has gained 70-80% of its design strength, under normal curing conditions, this occurs on the 7th day. But this is for general monolithic works including massive structures, in private construction, in private construction, in compliance with the technology of concreting and subsequent care for the laid concrete, depending on the massiveness of the structure, decompression can be carried out on 4-5 days.

Formwork removal, disassembling

The formwork should be carefully dismantled in order to avoid the destruction of the formwork and concrete structures. The surfaces of the formwork, which will still be used, should be cleaned with metal brushes and scrapers from the remains of concrete mixture and lubricated with a special emulsion. In case of large sinks and spalls on the concrete surface, it can be cleaned and grouted with cement-sand mortar. Remove the formed concrete surface buildup with a trowel.

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Concrete cutting tips

1) Allow the saw to cut evenly

The diamond cutter should always move naturally in a straight line, as any misalignment can affect the result. The cutting process should take place in a controlled environment. If you want to do it right, it is best to draw a straight line where the cut will go and then allow the saw to pass the material without adjusting halfway through.

2) Avoid bends

A fairly common mistake when diamond cutting concrete occurs when a novice cutter tries to make a smooth angle.

3) Use the right diamond disks

Choosing the right cutting disks is also important for smooth cuts. Poor quality cheap blades will give you wobbles. Always use only quality blades for diamond cutting concrete!

4) Think about safety

This is an important tip to consider when cutting concrete. It is essential to have the proper safety gear to ensure your safety while cutting concrete.

Believe it or not, it actually helps when cutting as it helps you better focus on the process rather than how to save your limbs.

5) Plan ahead

Planning is paramount when it comes to cutting concrete. By planning ahead, the right steps to take, you can save a lot of time and actually achieve the best possible result.

6) Turn to the professionals

The best guarantee of quality is always the professionalism of the craftsman. While achieving smooth concrete edges requires precision and the use of the right equipment, it is also important to seek professional help whenever possible.

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Covering with PVC sheeting: provides additional insulation and protection from low temperatures. This method is effective at moderate frosts.

Heat guns: are installed to maintain heat at the construction site. are used to create a thermal “tent” using polyethylene over the poured concrete surface. This allows concrete to harden quickly even at extreme low temperatures (concrete will set in 1-2 days).

Anti-freeze fillers: added to the concrete mix to prevent water in the mortar from freezing. They are used in frost and winter concrete.

Paving concrete in winter

Paving concrete in winter requires additional steps to preserve its qualities
To prepare concrete mix in winter conditions and preserve its qualities, the following recommendations should be considered:

• Heating of aggregates and water: this is achieved by heating the aggregates to 60°C and the water to 90°C. The cement is not heated, which ensures a final mix temperature of about 35-40°C.
• Filling the mixer drum with water: the drum is first filled with water and then the mix is added, ensuring more even heat distribution.
• Extending the mixing time: extending the mixing time by 1.2-1.5 times contributes to more efficient uniform heating.
• Transportation in insulated closed containers: to prevent cooling of the prepared mortar during transportation.

The base on which the concrete will be placed is heated to positive temperatures and thoroughly cleaned of ice and snow. The reinforcement may also need to be heated if its temperature is below 10°C. The concreting process is carried out at a rapid pace so that each previous layer of concrete has time to set before the temperature inside drops significantly.

Many builders wonder at what temperature concrete can be poured in winter and our experts have the answer: winter concrete can be poured at temperatures from +5°C to 0°C, frosty M5 – from 0°C to -5°C and frosty M10,15 – from -10°C to -15°C. That is, depending on the temperature regime, you can lay concrete from 0 to -15 ° C, the main thing is to choose the right material.

Temperature during concreting in winter

The use of electric heating of concrete is usually justified on large construction projects with powerful transformers. However, its cost makes it ineffective for private buildings in the current state of domestic power grids.

The most reasonable and affordable method to protect concrete from freezing is its covering, which is effective in the temperature range from +3 to -3 °C. Simple covering of concrete with polyvinylchloride film or other heat-insulating material allows preserving the heat released by cement when it interacts with water. Creating an artificial greenhouse effect also provides good results, but requires immediate covering of the fresh construction. However, covering is effective only in certain temperature conditions, and with a sharp drop in temperature to -5 or -15 ° C, becomes impractical, requiring the transition to the use of gas or electric heat guns.

When heating with heat guns, it is also necessary to use PVC film or other insulation for temporary shelter, providing sufficient conditions for rapid achievement of concrete strength within 3 days.

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