Using modular concrete formwork panels and corners, it is possible to form and construct a concrete column with a square or rectangular cross-section in accordance with the existing formwork and design drawings
External corners have chamfers, and punched corners are used at the corners of the columns.
In the formwork of various column shapes, including: Square, L-shaped, octagonal, and other column shapes can be easily formed and executed by combining metal concrete formwork panels, external and internal corners, and punched corners, as well as other formwork connections. In general, column formwork with the above-mentioned geometric shapes consists of two main parts: the formwork wall (metal panels) and the sleeve or confinement (tubular or cylindrical).
The performance of column formwork walls is similar to that of wall formwork walls. The confinement, supports, and formwork wall constitute the internal stability of column formwork, ensuring its stability. It is evident that to maintain the verticality of columns and external stability, inclined braces in two types, tension (such as cables) and compression (jacking), should be used.
Column formwork with square or rectangular cross-sections:
In the formwork of square or rectangular cross-section columns, various combinations of modular concrete formwork, external corners, and punched corners are used. To prevent the complexity of column formwork, for dimensions larger than 50*50, tubular confinement (collar) is employed.
Tubular confinement is typically connected to the column formwork in four parts using intermediate clamps (clips). The dimensions of tubular confinement are usually 75*75, 80*80, and 100*100. Therefore, for each column, 8 tubular confinements and 32 intermediate clamps are required.
To prevent sharp corners on the column after construction, which could lead to the risk of concrete spalling, corners are typically produced with chamfers, creating beveled edges at the corners of column sections (which become visible after formwork removal). In the connections of formworks, pins and male-female connectors, as well as clamps (frog clips), are used.
Another method is using integrated formworks for concrete columns. In this approach, the formworks are constructed and executed in stages based on the shape of the column and the height of the concrete pour. These formworks are commonly referred to as “L-formworks.” The mentioned method results in the rapid installation of the formworks and, due to the integration of the formworks, their quality is superior compared to other similar formworks. It should be noted that these formworks are considered as special panels and cannot be used in other members and structures, which results in an increase in project costs. Furthermore, the weight of the formworks and the essential need for a crane to move the form panels can potentially create challenges for the project. .
Expandable concrete column formwork:
These formworks can be moved as a whole by a crane. The “expandable column formwork” is designed and constructed to withstand a pressure of up to 80 kn/m^2 for fresh concrete. The cross-sectional dimensions of the column formwork range from 20 × 20 centimeters to 60 × 60 centimeters with 5-centimeter increments, allowing for the formwork of square or rectangular sections. These formworks occupy less space after demolding, which is crucial for the organization and movement within the workshop environment.
Circular column formwork:
Circular column formwork is designed and constructed based on the diameter and height of the column. For columns with different diameters, round column metal formwork features a smooth surface with minimal joints and grooves. These concrete formworks have horizontal and vertical connection boundaries that allow for formwork removal after each stage of concrete pouring. .
The vertical connection of two semi-circular concrete formworks is done using pins and wedges as well as clamps, while the horizontal connection of two round concrete formworks that are placed on top of each other is performed using screws and nuts. Circular column forms are typically constructed with diameters ranging from 30 to 150 centimeters and lengths of 100 and 150 centimeters. If a mushroom column head is required, a mushroom column head formwork is installed on top of the circular column formwork.
Polygonal column formwork:
Polyhedral column formwork is designed and constructed for polyhedral columns, and in the design of these formworks, an attempt is made to use modular panels. The corners of these formworks (polyhedral column formworks) are of a special type, with angles exceeding 90 degrees.
Integrated round column formwork:
Round column formwork is designed and manufactured as a single unit. After being placed in their designated positions by a crane, the mentioned formworks are brought together by special connections to form a complete circular section.
Column formwork with a capital:
In some projects where the ceiling consists of various flat beams and slabs, mushroom column capitals are designed to reduce the column’s cross-section and increase the load-bearing capacity at the top of the columns. These columns are typically designed for special projects such as water resources.
Advanced column formwork:
Rapid Concrete Formwor:
Rapid formwork is a type of aluminum column formwork used to create a smooth concrete surface and features unique connections. The allowable concrete pressure tolerance for this formwork is very good, up to 120 Kn/m^2 This formwork is adjustable for square and rectangular sections without limitations up to 60 × 60 centimeters. The frames of this formwork are coated with powder paint, which is easy to clean. Additionally, the assembly of this formwork is done without the need for a crane. A concrete pouring base is pre-prepared on top of the formwork, which is adjustable for any column section. .
QUARTTRO Concrete Formwork: QUARTTRO is a rapid construction column formwork. This type of concrete formwork can lift all four of its units in one go using a crane. The maximum allowable concrete pressure capacity for this formwork is up to 80 kn/m^2. These formworks are suitable for square and rectangular column sections up to a maximum of 60×60 centimeters with 5-centimeter increments. The best smooth concrete finish is achieved by using multi-layer plywood with a thickness of 21 millimeters, which is installed behind these formworks. Due to the collapsible nature of its column frames, each set of 4 formworks occupies only a height of 60 centimeters during transportation. At the top of the formwork, the concrete pouring base support is pre-fabricated and adjustable to fit any column section.
SRS Steel Circular Column Formwork :
This mentioned formwork is a circular steel column formwork that provides the best concrete surface appearance. This formwork is suitable for column sections with 5 cm increments up to a diameter of 70 cm. The permissible pressure capacity of fresh concrete for these formworks is high, reaching up to 150 kN/m^2. Achieving the best concrete appearance is safe and convenient when using special high-quality steel and powder coating. It can be applied to the concrete casting base for any column section .