The laying of concrete turns out to be a very important task since if it is not done correctly, the technical characteristics for which it was projected and manufactured could not be achieved. Let’s see, next, 6 methods to correctly carry out this work.
The pouring of concrete consists of a set of operations carried out to arrange the fresh concrete, just received or manufactured, in the corresponding molds or formwork. Accordingly, to Concrete Utah Contractor, the placement must be carried out in such a way that the components of the mixture are not disintegrated, for which we will see some recommendations and provisions that we must follow during this operation.
There are different methods for pouring concrete, so concrete contractor Utah will always choose the most appropriate one depending on the means available and the accessibility to the place. Let’s go there!
1. Concrete Pouring: Bucket Crane
This system consists of loading a bucket or cupola and, with the help of a crane, moving it to the exact place of the work where it is desired to pour. In that place, there will be an operator who will receive the cupola and place it properly so that the pouring, which can be carried out from the bottom of the bucket or one side of it, is carried out correctly.
This concreting system is very common in building works since it can be carried out with any type of truck crane, or even tower cranes, of which we can frequently find on a construction site. The capacity of the buckets can vary from 0.5 to 8 m3, the most used being 1 m3. In any case, discharge from a prudent height should be considered in order not to segregate the material when precipitated.
2. Pouring Method
It is based on lifting the cupola through the use of cables. To do this, two pillars embedded in the ground are arranged, joined by a carrying cable on which a trolley moves which, in turn, transports the cupola. This concreting system is widely used in large dams, where access by land is complex.
3. Placement of Concrete with Conveyor Belts
The conveyor belt concreting system allows continuous concreting, unlike the two methods described above. The belt allows us to place concrete with a maximum size of high aggregates, although we must bear in mind that to use this system, the concrete used must have a plastic consistency.
If this method is used, it is advisable to have “tubes” or conduits that prevent free fall to a certain height of the concrete, which would cause its disintegration.
4. Pouring Concrete from Conveying Equipment
One of the simplest and most used ways to put concrete on the job. It consists of pouring the material directly from the concrete mixer truck in which it has been transported, through a chute.
To be able to carry out this concreting system, we must place the concrete mixer truck very close to the formwork, so it requires having enough space and accessibility to execute it correctly. This system, like the previous one, allows concreting continuously.
5. Pumped Concreting
In this case, the concrete is transported through a pipeline from the truck that transports it to the construction site to its place of installation, driven by a rotary or piston pump.
For concrete to be pumped it must have a series of specific characteristics that allow the success of the operation. Thus, the seat of the Abrams cone (consistency test) must be between 8 and 20 cm to avoid problems of segregation of coarse aggregate and blockage of concrete within the pipe. Regarding aggregates, sand must correspond to 40-45% of the total aggregates, while the proportion of fines must be between 350 and 400 kg / m3, also, the water-cement ratio must be between 0, 5 and 0.6.
It should be noted that the pumps allow continuous concreting, obtaining good performances and reaching difficult-to-access points, it is also a technology that is in continuous advance and allows the choice of the type of pump among a wide variety of them. However, there are also several drawbacks that we must take into account when selecting this method, such as that to make it economically profitable we will have to pour around 30-150 m3 / h since it involves a complex installation process, which requires specialized staff and detailed planning that end up increasing its cost.
6. Recommendations for Pouring Concrete
Some Simple Recommendations:
- The concrete must not be poured from a great height, avoiding its free fall and ensuring that its direction is vertical. In the same way, we must ensure that there are no horizontal displacements of the mass.
- The concrete must be guided during the pouring, using gutters or other devices that prevent its free collision with the formwork or the reinforcement.
- The concrete will be placed by horizontal layers, of sufficient thickness, to allow good compaction. The different layers will be consolidated successively together, each one to the previous one, without a long time, elapsing between layers to prevent the dough from drying out or starting to set.
- The concrete must not be distributed with rakes, since it would cause its disintegration.
- According to the regulations, the time elapsed between adding water to the mix and placing the concrete must be less than an hour and a half depending on the temperature.
Interesting Related Article: “5 Little Known Advantages of Concrete Pavements“