Simple ways of Construct a Multi-storey Column

      

COLUMN is a structural element that transmits, compresses the weight of structure above to the other elements below, Columns are referred as compression members because compression forces dominate their behaviors. Columns are frequently used to support Beams or arches on which the upper parts of walls or ceilings rest.

1. Setting out of Kicker

Kickers are lateral support for concrete formwork, it is provided to ensure that the coordinates of the column are maintained uniformly between the slabs and essentially throughout the structure. Its purpose is to avoid uneven steel cover and Column alignment issues which are almost impossible to rectify once concrete is casted and can be easily rectified by providing a kicker.

•    Center to center alignment setting

This involves measurement to obtain the center to center dimensions of which helps on setting the columns so as they can be aligned in a straight line, manila rope can be used or Theodolite so as to maintain columns in proper alignment, marking on top of the slab according to the column size in structural drawings.

• Kicker setting

Setting of kicker helps to maintain the shape of the column in its particular dimensions by preventing movement of column boxes. Timber boxes size of concrete column and 50mm high must be fixed and aligned properly in the positions of column, concreting and allow to harden for 48 hours.

2.Steel fixing

After marking the column locations, what next is to fix reinforcement as instructed in the structural drawings

•    Work bench

This involves the whole process of straightening, cutting and bending of steel. Measure and mark the dimensions of steel bars and tie-steel ring, Bend steel reinforcements and stirrups according to bending schedule.

Bend Steel bars at the bottom to allow for alignment with starter bars, THE PURPOSE IS TO TRANSMITS THE FORCES DIRECTLY TO THE COLUMN REINFORCEMENTS.

•  Steel fixing

The tie-steel rings are fixed to the desired shape and required dimensions then the steel bars are inserted and tightened by the binding wire to make the steel skeleton for the column. Block spacers are capped on reinforcements purposely to maintain cover and to keep to the required distance away from the edge of the concrete.

•  Steel positioning

Steel skeleton for the column connected on the over-protruding steel bars.

3.  Column formwork construction.

Column formwork is a term used for structures that are used to support molds for poured concrete.

•     work bench

This involves cutting of marine boards according to column height, length and width and then nailed with along timber (size 2” by 4”) vertically.

•    Column forms and joint

Mainly involves nailing vertical timber frames around column boxes, this forms strong joint and helps to retain column boxes in their shape.

•    Column formwork and bracing

Struts support Column boxes, where timber poles are nailed at a certain angle to column boxes and supported on the floor.

Column formwork bracing performs two functions:

• It maintains the accuracy of the column form position and plumb so that it is within tolerance.

• With stand results of forces acting on either the column formwork or the bracing. The forces may be wind or

Impact. These impact forces can occur from the collision of concrete buckets or concrete vibrator.

•    Plumb a column

After column fixed in its final position, lastly you check vertical alignment of the column.

4.     4. Casting of concrete on column boxes

This involved mixing of cement, sand, and aggregate aiming to obtain the designed concrete grade.