How to Make Concrete
Plan your project carefully., Purchase or gather the raw materials., Assemble or buy a mixing container., Build the forms., Mix the cement and sand., Add the gravel or crushed stone., Add water., Thoroughly mix the concrete., Pour and float the...
Step-by-Step Guide
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Step 1: Plan your project carefully.
Having a detailed plan for your project will help you avoid a lot of problems later on.
Decide on the area to be concreted, draw up a plan, and write in all measurements.
Determine the finished levels of the work and write these levels on the plan.
Determine the thickness (depth) of the concrete and write it on the plan. 4 in. (10 cm) depth is standard for driveways and garages used by passenger vehicles, but not for heavy trucks.
Remember to allow for drainage and ensure that water will not run to undesired locations.
Provision a minimum drop of 1" for each ten feet of slab (1.2cm per m), although
1.5" drop for every ten feet of run (1.8cm per m) is preferred. -
Step 2: Purchase or gather the raw materials.
Generally, you will need Portland Type I (general use cement) or Type II (used for structures in water or soil containing moderate amounts of sulfate, or when heat build-up is a concern) cement, masonry/builder's sand or other clean sand, and gravel or crushed limestone.
Calculate the volume of concrete required by multiplying the thickness in feet by the square footage of the area to be concreted.
Purchase as much concrete as needed for your project. 1 square foot (.093 sq. m) of 4 in. (10 cm) deep concrete requires 50 pounds (22.7 kg) of concrete mix.
Portland cement generally comes in bags weighing 96 lbs (43.5 kg) and should be handled with care.
Depending on the size of your project, a truck may be needed to assist in hauling. , Build a mixing box from wood planks or use a sturdy wheelbarrow to mix the materials.
If your project is large, rent a mechanical mixer to do reduce the human labor. , In order to contain the wet concrete, assemble the forms along the outer edges of the area you will be placing the concrete in.
Use timber boards to assemble the forms.
Brace the boards securely, ensuring that they are strong enough to support the weight of the concrete.
Check that the form work is level.
If you are plumbing underneath the concrete, ensure it is in the proper place.
Confirm that the dimensions of the forms match the dimensions laid out in your plans. , Prepare your dry mix by mixing the cement mix and sand.
There are a few common mixtures and methods for concrete preparation.
Option 1:
A basic mixture for mortar (not concrete) is made using a 1:2:3 ratio of water to cement to sand by volume.
Option 2:
General purpose concrete is created using a 1:2:3 ratio of cement to sand to gravel by volume. , Incorporate the gravel or crushed stone in the dry mixture.
Add gravel or crushed stone at a ratio of up to 5 parts gravel per 1 part cement and sand mixture.
The gravel doesn't adversely affect the tensile strength of the concrete unless you add too much.
If the gravel doesn't leave enough cement paste to fill the cracks between the gravel, you have added to much.
Adding too much gravel can also make it difficult to get a smooth finished surface on the cured concrete. , Begin by adding water to the mixture slowly, mixing continuously until the concrete becomes plastic enough to place in your form.
The plastic character of the concrete is measured in "slump"
which is determined by filling a metal "slump" cone with the mixed, wet concrete, lifting the cone off gently, then measuring how far the concrete sags, or slumps.
The typical "slump" of good structural concrete is about 3 or 4 inches (7.5 or 10 cm). , Continue mixing until the concrete has a uniform consistency.
The texture should be even throughout the mix, with no pockets of dry material.
Continue mixing for two or three more minutes to begin the hydration process, which is ultimately what causes the concrete to harden. , Add the concrete to your form, tapping all the edges to remove air pockets, and let it settle in evenly and firmly.
Using a magnesium float or a smooth flat board, level the concrete across the top.
Do this by dragging the tool, tilted slightly upward on the leading edge, across the surface of the concrete.
This process is known as "floating" and will float the fine cement paste to the surface.
The fine paste is malleable and easy to smooth and finish either by brushing, brooming, or troweling when it begins to "set" or harden. , After floating, leave the concrete alone until it becomes firm enough to finish without leaving tool marks.
Lay out "knee boards" or pieces of plywood that you can walk on without sinking into the concrete.
Crawl onto the slab with the appropriate hand tools and finish the concrete into a smooth surface.
For very large slabs, you will need a "bull float" and possibly a power troweling machine.
This is an investment that is better left to professionals.
After the concrete is placed and finished, cover it and protect it from extreme temperatures and rain for a few days. , Gather and clean all the tools and the mixing container as soon as you are finished with them.
Cured, hard concrete is difficult to remove.
Take special care to clean rented equipment, as the rental company often will charge an additional cleaning fee when you return them. -
Step 3: Assemble or buy a mixing container.
-
Step 4: Build the forms.
-
Step 5: Mix the cement and sand.
-
Step 6: Add the gravel or crushed stone.
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Step 7: Add water.
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Step 8: Thoroughly mix the concrete.
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Step 9: Pour and float the concrete.
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Step 10: Let it dry and finish it.
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Step 11: Clean up the work space.
Detailed Guide
Having a detailed plan for your project will help you avoid a lot of problems later on.
Decide on the area to be concreted, draw up a plan, and write in all measurements.
Determine the finished levels of the work and write these levels on the plan.
Determine the thickness (depth) of the concrete and write it on the plan. 4 in. (10 cm) depth is standard for driveways and garages used by passenger vehicles, but not for heavy trucks.
Remember to allow for drainage and ensure that water will not run to undesired locations.
Provision a minimum drop of 1" for each ten feet of slab (1.2cm per m), although
1.5" drop for every ten feet of run (1.8cm per m) is preferred.
Generally, you will need Portland Type I (general use cement) or Type II (used for structures in water or soil containing moderate amounts of sulfate, or when heat build-up is a concern) cement, masonry/builder's sand or other clean sand, and gravel or crushed limestone.
Calculate the volume of concrete required by multiplying the thickness in feet by the square footage of the area to be concreted.
Purchase as much concrete as needed for your project. 1 square foot (.093 sq. m) of 4 in. (10 cm) deep concrete requires 50 pounds (22.7 kg) of concrete mix.
Portland cement generally comes in bags weighing 96 lbs (43.5 kg) and should be handled with care.
Depending on the size of your project, a truck may be needed to assist in hauling. , Build a mixing box from wood planks or use a sturdy wheelbarrow to mix the materials.
If your project is large, rent a mechanical mixer to do reduce the human labor. , In order to contain the wet concrete, assemble the forms along the outer edges of the area you will be placing the concrete in.
Use timber boards to assemble the forms.
Brace the boards securely, ensuring that they are strong enough to support the weight of the concrete.
Check that the form work is level.
If you are plumbing underneath the concrete, ensure it is in the proper place.
Confirm that the dimensions of the forms match the dimensions laid out in your plans. , Prepare your dry mix by mixing the cement mix and sand.
There are a few common mixtures and methods for concrete preparation.
Option 1:
A basic mixture for mortar (not concrete) is made using a 1:2:3 ratio of water to cement to sand by volume.
Option 2:
General purpose concrete is created using a 1:2:3 ratio of cement to sand to gravel by volume. , Incorporate the gravel or crushed stone in the dry mixture.
Add gravel or crushed stone at a ratio of up to 5 parts gravel per 1 part cement and sand mixture.
The gravel doesn't adversely affect the tensile strength of the concrete unless you add too much.
If the gravel doesn't leave enough cement paste to fill the cracks between the gravel, you have added to much.
Adding too much gravel can also make it difficult to get a smooth finished surface on the cured concrete. , Begin by adding water to the mixture slowly, mixing continuously until the concrete becomes plastic enough to place in your form.
The plastic character of the concrete is measured in "slump"
which is determined by filling a metal "slump" cone with the mixed, wet concrete, lifting the cone off gently, then measuring how far the concrete sags, or slumps.
The typical "slump" of good structural concrete is about 3 or 4 inches (7.5 or 10 cm). , Continue mixing until the concrete has a uniform consistency.
The texture should be even throughout the mix, with no pockets of dry material.
Continue mixing for two or three more minutes to begin the hydration process, which is ultimately what causes the concrete to harden. , Add the concrete to your form, tapping all the edges to remove air pockets, and let it settle in evenly and firmly.
Using a magnesium float or a smooth flat board, level the concrete across the top.
Do this by dragging the tool, tilted slightly upward on the leading edge, across the surface of the concrete.
This process is known as "floating" and will float the fine cement paste to the surface.
The fine paste is malleable and easy to smooth and finish either by brushing, brooming, or troweling when it begins to "set" or harden. , After floating, leave the concrete alone until it becomes firm enough to finish without leaving tool marks.
Lay out "knee boards" or pieces of plywood that you can walk on without sinking into the concrete.
Crawl onto the slab with the appropriate hand tools and finish the concrete into a smooth surface.
For very large slabs, you will need a "bull float" and possibly a power troweling machine.
This is an investment that is better left to professionals.
After the concrete is placed and finished, cover it and protect it from extreme temperatures and rain for a few days. , Gather and clean all the tools and the mixing container as soon as you are finished with them.
Cured, hard concrete is difficult to remove.
Take special care to clean rented equipment, as the rental company often will charge an additional cleaning fee when you return them.
About the Author
Jennifer Morales
Enthusiastic about teaching pet care techniques through clear, step-by-step guides.
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