Waffle Slab Construction using Removable Formworks
In general, the implementation of the waffle slab could be defined step by step as follows:
Step 1: Removable Support Structure
Horizontal and vertical supports should be arranged first to withstand the load of the roof and waffle molds before concrete pouring. The equipment used for supporting in waffle slabs are as same as other concrete slabs.
Step 2: Waffle formwork Embedment
In the second step, waffle formworks are placed in the specified areas according to the structure plan. Zagrosbana's durable formworks are designed in such a way that they do not need lubrication and could be easily removed from the bottom.
Step 3: Placing the Reinforcement
Reinforcement is placed according to the plan. Shear reinforcement should be also embedded on the right places according to the structural plan.
Step 4: Supplying the Concrete
Concrete pouring in waffle slabs is very convenient and easy to control. Because unlike other slab systems such as U-boot and Cobiax, there isn’t any concrete under waffle formworks. Therefore, there is no need to have vibration in the below part.
Step 5: Formwork Removal
Waffle formworks will be removed after concrete hardening and could be reused for upper roofs or other projects.
Step 6: Finishing up the Project
Finally, after constructing all roofs in a building using one series of waffle formworks the project will be more cost efficient compared to other slab systems.
What is waffle formwork?
Waffle slab is the most technical and economical type of roofs among conventional systems. The main element in the construction waffle slabs is waffle formwork. Different companies manufacture formworks with different materials but generally there are two types of waffle formworks: one-way and two-way. One-way waffle formworks are in rectangular form with the widths of 60 or 70 cm and different lengths. two-way waffle formworks are cubes with different depth.
Waffle Slab Advantages
Removing span length limitations
Waffle slabs could be used for the larger spans and where the number of the columns or their position is of paramount.
High load carrying capacity
The load carrying capacity of waffle slab is much greater than other slabs in equal weight. Also it has much less weight compared to slabs with equal load carrying capacity.
Pleasant appearance with high stability
Waffle slabs have high stability and desirable structure additional to their beautiful appearance which could be used as an exposure. Hence they could be used in building airports, hospitals and so on.
Less vibration and more earthquake resistance
The roof with waffle slab has good vibration control due to the existence of auxiliary reinforcement on both directions. Therefore, it is very suitable for public buildings to control vibration caused by population movement.
Less concrete requirement, compared to the other systems
The waffle slab is lightweight and requires less concrete than all similar systems, so it is cost-effective.
