Concrete of the building needs support until it becomes hard. Concrete formwork provides support for the concrete. Formwork and shoring are the two main categories of the temporary structure which provide support for the concrete. Vertical forms are referred to as formwork and they are used for the construction of walls and columns. The horizontal formwork is referred to as shoring. Horizontal formwork is used for supporting slabs and beams construction. Formworks should resist all types of loads like vertical load and lateral loads. Formworks are exposed to heavy loads during transportation and also when they are used in the construction site.
Concrete column formwork can be custom designed as per the requirement of project or it can also be pre-designed as per the common standards. Pre-engineered formworks can be used in different locations and can be easily reconfigured and can be quickly assembled based on the requirement of the construction site. There is a limit in the capacity of the load for the pre-engineered formworks, panels used in this type of formworks are fixed and they are not suitable for all construction size and type. This is some of the disadvantages of the pre-engineered formworks.
The efficiency of the construction work can be increased with the help of custom-designed concrete column formwork. It can be designed for all the type of buildings and load but they can’t be reconfigured at a different location. Wall and column forms are assembled on the flat ground and then they are lifted to the position. If the size of the panels is tall then there may be the formation of some bends. For protecting the forms from the bends the formwork should be designed carefully to protect the overload. After placing the forms on the position it should be braced to prevent the forms from the wind.
Concrete column formwork design considerations :
Based on the time period there are different standards for designing the structure and properties of the formwork. ASCE-7, ASCE-37 and ACI 347 are some of the standards that are followed while designing column formworks. There are many factors that impact the pressure of the lateral concrete. Type of the concrete, height of the pour, rate of fall, usage of superplasticizers are some of the factors that affect the pressure. During the design stage of the formworks fix the concrete pressure and all other related terms. Based on the type of concrete and pour rate decides the pressure of the concrete. If slow set concrete or high pour rate is used then design formworks with high concrete pressure.
Shore type formworks are used for supporting the dead load and the live load type of the surface. There are four different working surfaces and they are specified in ASCE 37. The four categories of working surface are the heavy-duty, medium-duty, light-duty and very light duty working surface. This type of formworks is used for small horizontal weights. Seismic force is not included for small duration construction projects. Shore formworks are designed to prevent lateral forces which are normally formed because of wind and also pre-defined horizontal loads.