Construction Procedure of Concrete Floors

Concrete slabs are widely used in the construction industry for various kinds of buildings including commercial, institutional and residential buildings. This article covers the four main steps for Construction Procedure of Concrete Floors including setting up the formwork, laying the slab reinforcement, casting and finishing concrete, and finally curing followed by removal of formwork. 

Step 1: Preparation of formwork

Prior to the actual setting up of the formwork, engineers design the elements of formwork to resist the expected loads including pressure/impact of fresh concrete, weight of moving workers on top of formwork and weight of machines/devices used for construction. Various materials are available to choose from for the formwork such as wood and steel. During this stage, care should be given to eliminate the causes of failures of formworks.

Step 2: Laying out the reinforcement

The next step after setting up the formwork and making sure it is safe for concrete placement is preparation of the reinforcement bars.

Few points need to be considered here:

• Compare the dimensions of formwork to the plan dimensions.
• Clean the formwork from any debris and if needed, oil the formwork just a little bit.
• Make sure labors cut the bars to the required length without having so much waste.
• Place the bars in their corresponding locations while maintaining the concrete cover and bar spacing.
• Thin steel wires are applied to tie the reinforcement mesh. 

Step 3: Casting and finishing concrete

Concrete can be either mixed on site or mixed in a concrete plant and transported to the site. For concrete floor, casting concrete starts with placing concrete at perimeter locations at one edge with each batch being poured against previously cast concrete. 

Place concrete close to its final location to prevent multiple movements on the concrete, causing segregation. It is not advisable to make big separate pile of concrete and pushing them horizontally to final location. 

Following casting, compaction of fresh concrete starts to properly mold concrete in the corners of formworks and eliminate the formation of honeycombs and large air pockets. Finally, the surface of concrete shall be finished to provide the horizontal surface we are used to.  

Step 4: Concrete curing and removal of formwork

After setting of concrete, curing shall be started. Several methods exist for curing including water curing which is spraying of concrete with water. In such method, burlap covering can be used to help maintaining water on the surface and reduce spraying frequency. Also, curing compounds can be applied as a method of curing.

Removal of formwork is recommended to be done after 14 days.