Concrete is the most widely used construction material in the world. It is used more than steel, wood, plastic and other building materials.

Concrete is a mixture of Cement, water, sand and coarse aggregates, which is mixed in required proportions. As concrete plays a very significant role in the construction, it is good to have an idea for any construction worker of how to mix concrete by hand. It not only helps to have construction knowledge but also gives a better understanding of how concrete works.

Personal Protection Equipment

     Concrete possess abrasive and skin-drying properties, which can cause skin irritation, severe chemical burns, and eye injury. To avoid direct contact with cement or concrete, one should

•  Wear construction boots and construction gloves that should fit perfectly.
•  Wear safety goggles to avoid direct eye contact.
•  Wear tee-shirt length sleeve and long pants that tuck inside boots.

If any cement or concrete gets in touch with the body or eyes, rinse it immediately with water and take medical care as soon as possible.

Prepare Materials and Equipment Required

     Prepare the materials well enough to mix them in adequate proportions.

• Use Portland Cement that hardens underwater and acts as a binding agent when mixed with water and aggregates.
• The sand should be washed out cleanly to remove impurities present in it before using in the mortar.
• Gravel used should be of the required size as it is a crucial ingredient that adds strength and durability to the mix.
• To mix the concrete use shovel or any small tool, or you can use your hands if you want for mixing smaller quantities.
• Buckets are required to carry water and concrete and also for measuring material proportions. A wheelbarrow or wheel barrel can also be preferred for transporting concrete to the constructing area.
• Don't forget to prepare yourself with personal equipment when mixing or managing concrete to avoid skin diseases and eye injuries.

Mixing Proportions of Concrete

     The ratio of aggregate to sand to cement is crucial to produce a strong and durable concrete mix. The volumetric mix ratio is 1:2:3, one bucket of cement is mixed with two buckets of sand and three buckets of aggregates.

The size of the bucket does not matter as long as you maintain 1:2:3 ratios to mix a batch of concrete. Materials needed for 1 cubic meter of concrete is 0.25 Cement (m³), 0.50 Sand (m³) and 0.75 Gravel or Aggregates (m³).

Steps for Mixing Concrete

     Step 1 - Gather a group of people and assign someone as a Safety Manager, who look after them and also lead them to a quick safety session to be aware of all possible hazards.

     Step 2 - Look for a dry workplace to mix the concrete and make it clear from loose dirt, rocks or other materials to avoid mixing with the concrete.

     Step 3 - Assemble the materials required for the mix that includes Portland Cement, Sand, Gravel, Water, Buckets and Shovels. Make sure that the ingredients should not get wet before mixing.

     Step 4 - Measure the materials by multiplying or dividing the ratio as mentioned earlier, you can use a shovel to fill the bucket with cement.

     Step 5 - Carefully take out the filled bucket and gently dump the cement on the ground level. Avoid pouring of cement too fast or too high, as it rises into the air and can get into your eyes, causing eye injuries.

     Step 6 - Measure the required amount of sand and place it next to the cement (in a circular form). Repeat the process till you get sufficient sand for the mix.

     Step 7 - Now, it’s time to mix the cement and sand, use a shovel to mix. Take one scoop of sand and put it on cement and mix them evenly. Repeat the process, scooping and mixing till you obtain the consistent texture of the mixture.

     Step 8 - After obtaining a uniform texture to the cement-sand mix, measure the gravel and put it just like the sand around the cement-sand mixture.

     Step 9 - Use a shovel and mix gravel with cement-sand, just like you did to mix cement and sand before.

    Step 10 - Create a place for water at the centre of the mixture (known as volcano-barrier), when the water is added, the surrounding material to it acts as a barrier and keeps it from running out.

    Step 11 - Add water carefully into the mixture in small amounts until you obtain desired consistency. The concrete should be mixed immediately after adding water. The concrete should not be too dry or too loose.

   Step 12 - Continue to mix the concrete in circular motion adding small amounts of water to it till you find the perfect consistency.

    Step 13 - Mix the concrete evenly without any dry pockets in it. Transport the concrete to the construction area using a wheelbarrow and pour it wherever needed before getting hard.

     Step 14 - After placing the concrete, clean the equipment and shovel using water.

     Don't store the remaining concrete for later use; once the water gets dried it loses its strength. These are some of the useful steps to follow while mixing concrete at construction sites.

Also, know: Ready Mix Concrete - Advantages & Disadvantages