If you are a project in-charge or a supervisor in construction projects, you need to know how to pour concrete. So that you can make defectless concrete structures with proper inspection.
Let’s discuss the steps involved in pouring concrete without further ado.
How To Pour Concrete In 10 Easy Steps?
Workers will do the work. You just need to arrange all the required things step by step and guide them properly how to go through all the steps to pour concrete.
Keep in mind that different concrete members require a slightly different approach to pour concrete.
I’ll discuss the steps in general. But I’ll guide you when you require a different approach.
So let’s begin with the…
Step #1: Be Prepared For Pouring Concrete
You know when you’re going to pour concrete.
Based on the deadline,
First, you need to estimate the required materials for concrete formwork and order them for purchasing.
Depending on the concrete member, you may need these formwork materials one month before the pouring date.
Look. I didn’t consider workers here. I assume that you’ve already hired a contractor to do the job.
Second, calculate the required steel quantity for the member you’re going to pour concrete.
Order the steel quantity for purchasing and make sure they arrive on your project at least 15 days before the pouring date.
Pro Tip: Don’t receive steel and shuttering materials at a time. If you do so, you might run short of storage space in your project.
Finally, Calculate the required concrete volume for the member.
And decide if you’re going to use ready-mix concrete or on-site machine mix concrete.
If you’re going to use ready mix concrete, contact with ready-mix suppliers.
Once you’ve selected the supplier, give them instructions about the grade of concrete and pouring date.
But if you want to use on-site machine mix concrete, you need to calculate the required materials for the concrete quantity.
And order materials for purchasing and make sure they’ll arrive on your site two-three days before the pouring date.
Once you receive the shuttering materials, you can now move to…
Step #2: Making Concrete Form
Concrete forms are built to keep the wet concrete in place.
You’ll have drawings of the RCC member that you’re going to make.
In that drawing, you’ll get the size and shape of the member. The form should be made based on the member’s details in the drawing.
Make sure the form is strong enough to withstand against loads of concrete, workers, and machinery.
Keep in mind that this form will stay in its place till concrete gain sufficient strength to carry the live and dead load.
Different concrete members require different approaches to make form.
For example, making a form for an isolated footing takes less effort than making a form for an RCC slab.
I’ve talked about concrete forms before. Read the following posts to learn more:
When the concrete form is almost ready, you can…
Step #3: Do The Rebar Works
In the structural drawings, you’ll get the reinforcement details of RCC members.
Find out the member in the structural drawing book that you’re going to pour concrete. And study the drawing to know the reinforcement details.
Based on the drawing, give instructions to the foreman to finish the reinforcement work.
One thing that should be considered here is some members like columns need to do the reinforcement work before the formwork.
In that case, the reinforcement work should be in step #2 and the formwork will be in step #3.
Once the rebar work is finished, you should…
Step #4: Clean Inside The Form And Make It Water-tight
At this stage, you’ll find cut pieces of steel and binding wire everywhere inside the form. You’ll also see dust.
To make the form ready for pouring concrete, clean all these unwanted things. You can spray water to clean dust and enlist someone to collect the materials which are not cleaned after water spraying.
After cleaning, make the form water-tight. So that cement slurry can’t penetrate once you start pouring concrete.
Related: Checklist of Slab formwork
Okay! You’re now ready for pouring concrete. For that…
Step #5: Get The Concrete Ready
It’s better to use on-site machine mix concrete for the small quantity of concrete.
If you need a large volume of concrete then order concrete from a ready-mix supplier. It’s economical and will save time.
It’ll also save you from many hassles. Such as ordering and storing concrete ingredients as well as arranging more workers.
If you’re going to use on-site machine mix concrete, make sure you’ve stored the required concreting materials in your project.
If you’re going to use ready-mix concrete, contact with the supplier and instruct them when you’ll need concrete.
Once the concrete is ready to pour, you can start…
Step #6: Pouring Concrete Into The Form
If you’re using ready-mix concrete, you can get the concrete in the place where you need it. Ready-mix suppliers generally use concrete pumps for this purpose.
If you’re using on-site machine mix concrete then you have to carry the concrete to the place where you need it.
However, the purpose is to get the concrete into the form.
When pouring concrete into the form keep one thing in mind that concrete shouldn’t be thrown more than 5 feet in height. It can cause concrete segregation.
At this stage, enlist some workers to spread out the concrete with shovels.
As soon as you start pouring concrete into the mold, you also need to start…
Step #7: Vibrating The Concrete
The freshly mixed concrete contains air bubbles inside it.
More specifically, if I say, the fresh concrete contains air bubbles approximately 5% to 8% of its volume.
If you don’t remove those air bubbles from the concrete, it’ll create honeycomb in hardened concrete. As a result, concrete will lose its strength and the structure will be weakened.
The purpose of vibrating is to consolidate the concrete.
The mechanism is, vibration removes air bubbles from the concrete.
It also helps many other ways. Such as, it rearranges the particles of concrete, helps to reach concrete to the corner of concrete forms as well as it helps to get better concrete finishing.
Follow the rules below to properly vibrate concrete:
- Make sure the vibrator is being placed vertically or nearly vertical position to maximize its effect.
- To properly consolidate the concrete, the vibrator head should be fully immersed in concrete and keep it there for at least 10 seconds. And then pull up the vibrator at a rate of no more than 3 inches per second. Often one inch per second gives the best result.
- Don’t allow to use vibrators as a concrete placement tool. Because this can create inconsistent concrete surfaces.
- The proper way of placing vibrator is to overlap the radius of the previously vibrated area. The radius is calculated the four times of the vibrator nozzle.
- Make sure vibration is stopped when air bubbles are no longer available in the concrete. Because over vibration can cause concrete segregation, and segregation will reduce the strength of concrete.
- So, train up workers for not over vibrating concrete. Experienced workers know when vibrating is proper. It is judged visually. When concrete looks blacky color and settled, it doesn’t need any more vibration.
Once the vibrating is finished, now it’s time to…
Step #8: Screed The Concrete
Starting at the uphill point, use a screening tool to flatten out the top surface of the wet concrete.
Screeding involves jiggling a wide plank of wood back and forth to create a flat surface.
At this stage, you need to make sure the top surface of the screeded concrete is up to the desired level.
After screeding, your concrete surface will begin to look more finished.
But it isn’t finished yet. To get a complete finished surface, you need to…
Step #9: Float The Newly-screeded Concrete Surface
The concrete will begin to set at this point. So you need to float the concrete surface fairly quickly.
Use both bull float and hand float to give the surface a finished and professional look.
Technically, concrete pouring is ended with this step. But to get the proper strength of concrete you need to…
Step #10: Cure The Concrete
The chemical reaction (which is called hydration process) between cement and sand, which binds aggregates, takes 28 days to complete.
If I simply say, concrete gains almost 99% of its strength within the first 28 days. It takes concrete’s lifetime to gain the rest 1% of its strength.
So, we need to make sure that within these first 28 days, concrete doesn’t face any problem in its hydration process.
To smoothen the hydration process of concrete we need to ensure the flawless curing process.
A major portion of concrete strength depends on the curing.
So curing should be done properly.
The purpose of curing is to keep the concrete wet, no matter which method you use for this.
Read More: Methods of Curing Concrete
A quality of a concrete structure mostly depends on the proper construction process of concreting members.
The purpose of this post is to get you familiar with the process of pouring concrete.
Although I described the process of pouring concrete in 10 steps, every step needs close supervision to ensure the quality of the structure.
Recently, I’ve published an ebook titled “Concrete Inspection Guidelines“.
The purpose of this book is to help you make defectless concrete members every time with proper inspection.
To know more about the book, click on the button below.