This article explains the most important factors to consider when pouring concrete. Basic steps and procedures should be followed when pouring concrete.
We start pouring concrete after going through the following procedure.
- Preparation
- Education
- Staking and leveling
- Concrete
- conclusion
- Cure
Preparation
We need to prepare ourselves before starting the formwork as the final step. However, part of the work in the first phase will have to be carried out in the preparation phase. At this stage we can list the following work steps that we essentially need to carry out before starting to concrete.
In this article we will look at the construction of a concrete slab.
- To continue work, you must first install the formwork.
- In the first phase, the beam floor (beam floor formwork) is placed to begin the reinforcement work.
- The beams are staked and then the beams are positioned according to their orientation.
- To attach the formwork to the lower beam, levels are marked on the supports.
- Next, we proceed to fix the beam reinforcements. This can be done in two ways.
- The first method involves fixing the reinforcement in the same location as the beam.
- Another method is to fix the beam reinforcement above the beam as it is very easy to handle and the beam reinforcements are lowered to the correct position after fixing the reinforcements.
- The plate reinforcement can also be fixed after the plate reinforcement is placed.
- Laying roof blocks also involves attaching reinforcements to maintain the roof for reinforcements .
- During these phases, the necessary checks are carried out to ensure that the reinforcement is fixed correctly in accordance with the project drawing.
- The consultant or project management team also carries out inspection work to check the reinforcements.
Education
At this stage we fix the formwork. However, it is necessary to secure the formwork part in order to proceed with the reinforcement work.
We first carry out the staking work before fixing the formwork. The necessary levels and staking work are carried out before formwork begins.
The grading machine and total station are used to determine correct heights and locate grid lines.
Based on the formwork design, supports (supports) are attached to the bottom of the beam. The spacing of the supports must be in accordance with the formwork design approved by the Engineer.
Once the beam reinforcement is fixed, the formwork panel is placed.
The distance between the formwork supports corresponds to the approved procedural instructions or approved formwork drawings. Once the vertical supports are fixed, the necessary beams are placed before placing the formwork panels.
The formwork must also be leveled before proceeding with fixing the reinforcement. Furthermore, we must carry out several checks before proceeding with concreting.
The article written as Concrete Column Formwork discusses column formwork and the aspects associated with selecting the appropriate formwork.
Also, the Wikipedia article could provide more information on formwork .
Staking and leveling
Checking staking and leveling are inevitable steps that must be carried out before concreting. The accuracy of the work that appears from the outside is determined by these steps.
The first step of the inspection is to ensure that the slab formwork is level. The leveling machine is used to check the ceiling height. Typically the ceiling height is checked from the soft shell.
After checking the reinforcement work, staking of the reinforcement work is carried out. At this stage we mainly check the staking of the supports, as when staking the support formwork other pickets are automatically covered.
If the column reinforcement is not aligned with the grid lines or is not vertical, a correction must be made before the concrete work begins.
The ceiling is then delimited. The distances marked on the slab formwork are used to implement the work.
For more information on slab staking, see the article Panel placement methods .
After completing all the checks, we proceed with the concreting.
Concrete
There are two things we need to discuss when pouring concrete
Basic concreting techniques and methods must be considered. First, we will discuss the most important aspects that need to be taken into consideration when concreting.
- Concrete setting time : When concreting, attention must be paid to the initial and final setting time. Generally, the initial setting time of concrete is about 45-60 minutes. However, it can be changed by adding additives. Setting time can be tested as mentioned in the article. 6 different cement tests . Setting time can be extended depending on design and testing needs during test mixes.
- Formation of cold joints : Cold joints occur when concrete is poured into concrete that has already hardened. Therefore, concrete must be poured before it hardens. When pouring large quantities of concrete, a new layer of concrete is poured before the existing layer begins to cure. This prevents the formation of cold joints.
- Casting pattern : When a large concrete casting is cast, a casting pattern is prepared to plan the casting order. Based on the planned sequence, the concrete is poured to avoid the formation of cold joints.
- Concrete compaction : To achieve the required quality and strength, the concrete must be sufficiently compacted. A Porker vibrator is used to compact the concrete. The duration of vibration depends on the thickness and type of mixture. Compaction should be carried out until trapped air is removed and the concrete is sufficiently compacted.
- Self-compacting concrete : In special cases where manual compaction of concrete is difficult, self-compacting concrete is used. The self-compaction of concrete is achieved by the composition of the mixture. Deep and large foundations, concreting piles, etc. are made with self-compacting concrete.
- Free fall height : Different guidelines specify different areas. It is usually 3 to 5 feet. Technically speaking, it is advisable to avoid free falling concrete as much as possible to avoid segregation.
- Temperature control : Depending on the size of the concrete, it is necessary to limit the temperature rise and control temperature fluctuations on the concrete surface. Methods of limiting the temperature rise of concrete are discussed in a separate article.
conclusion
The concrete work is completed in different phases. After the concrete has been poured, leveling takes place. Concrete can also be completed at this stage.
Additionally, finishing work can be performed when the concrete has hardened to the point where the trowel can be applied to the concrete.
Depending on the desired concrete surface and taking into account the irregularities of the concrete surface, the concrete work can be finished with plastering.
Concrete hardening
Curing is one of the most important things we must do after finishing the concrete work.
There are different methods and curing times for concrete.
The article 11 Methods for Curing Concrete could be used to learn about curing methods.
The article continues 6 Factors That Affect Concrete Curing Time could provide more information to help decide curing time.
Curing is generally mandatory after concreting, as it adds more benefits and safety to the concrete. Therefore, hardening should not be avoided. If we do not cure the concrete, the following main problems will occur.
- Cracks in concrete
- Affects the durability of concrete
- Reduction in concrete strength
Concreting varies from element to element. Let's discuss the methods available for pouring concrete.
Concrete columns and concrete walls
The supports are concreted through a contractor's pipe or through a cavity made in the support formwork to prevent segregation of the concrete during free fall.
Most commonly, a contract pipe is used inside the column to pour the concrete into the column. After each concreting, the concrete is compacted with a Porker vibrator.
Alternatively, the pump supply pipe can, if possible, be embedded directly into the concrete column.
When concreting with a pump truck, care must be taken to ensure sufficient compaction. Continuous concreting makes compaction a little more difficult.
Concrete slabs, beams and foundations
Pouring concrete on the slab is a common practice. It's normal. After completing the reinforcement work and obtaining all necessary licenses, concreting can begin.
Concrete can be poured onto the slab using a pump truck or manually placed onto the slab.
Concreting in piles
Pile concreting is different from other concreting processes. Special methods are used to concrete the piles.
After the excavation work is completed, the contractor's pipe is inserted into the excavated pile.
Rinsing is then carried out until the pile is completely clean. The necessary tests are carried out to ensure that cleaning is sufficient.
After receiving all permits for concreting, the contractor's pipe is filled with concrete. The tube is then slightly elevated so that the concrete reaches from top to bottom. This way, all loose materials are expected to rise with the original concrete.
Once the flow of concrete in the contractor stops, the concrete is poured again. The contractor is elevated slightly to allow the concrete to flow. When we do this, the end of the contractor pipe is always in the fresh concrete and the fresh concrete is not mixed with the starting concrete or the concrete that has been mixed with the bentonite.
This procedure can be followed until the pile is finished concreting. Contractor pipe should not be elevated above fresh concrete for any reason.
Furthermore, the flow of concrete must be controlled to avoid lifting the reinforcement cage. If the concrete flow rate is high, the reinforcement cage is raised and cannot be lowered later. Therefore, special attention must be paid in this regard.
