Specific Concept of Formworks for Column and Installation

1. The Concept of Formworks for Column

The characteristics of a column include a small section and size, but a relatively tall structure. Therefore, formworks for columns primarily address issues of verticality, lateral stability during construction, and resistance to lateral concrete pressure. Additionally, considerations must be made for facilitating concrete pouring, waste clean-up, and coordinating with reinforcement workers.

The concrete column forms available for sale consist of two outer panels sandwiching two inner panels. To ensure the formwork maintains its shape under concrete pressure, a hoop made of wood, steel-wood, or steel is placed externally around the panels.

The spacing of the column hoops depends on the concrete side pressure and the thickness of the panels. The pressure is greater near the bottom, necessitating more hoops closer to the base and fewer hoops toward the top. For larger column sections, back square columns are often placed behind the panels surrounding the column.

The upper end of the column formwork should feature a gap that connects with the beam formwork, based on site-specific conditions. To minimize wood usage, short horizontal panels may be applied on the two outer panels. When installing column hoops, vertical panels should be positioned outside the short horizontal panels for proper tightening.

2. The Installation of Formworks for Column

Before setting up the column formwork, the steel bars should be tied, and their elevation measured. The wooden frame at the base of the column formwork must be secured to the poured ground or the top surface of the foundation. The centerline is marked on the prefabricated panel, and the formwork is positioned along the column edge line and wooden frame, fixed using temporary diagonal braces. It is then calibrated with a hammer ball from the top to ensure vertical alignment.

Once corrections have been made, diagonal braces are utilized to secure the formwork in place. For columns aligned in a straight row, calibration must begin with the round column forms at both ends, followed by drawing an iron wire along the centerline at the upper opening of the column formwork to ensure proper alignment of the middle column formwork.