Monthly Archives: March 2015

Concrete Formwork

Concrete Formwork – is required to pour concrete wall and to support temporarily unsafe walls.
Formwork is a temporary construction; however care must be taken to prevent damage to permanent work. Three general principles govern formwork design and construction:
Quality accuracy of the concrete shape and the final finished surface quality.
Safety strength of the formwork structure. Personal safety of people, both carpenters and the public.
Economy The structural frame is usually the most significant cost component, a dominant and critical factor in the time of construction.

Concrete Shoring

They can be used under the following circumstances:

  1. When walls bulge out
  2. When walls crack due to unequal settlement of foundation and repairs are to be carried out to the cracked wall.
  3. When an adjacent structure needs pulling down.
  4. When openings are to be newly made or enlarged in a wall.

Types of shoring

  1. Raking shores (figure 1 to 3)
  2. Flying shores (figure 4 and 5)
  3. Dead shores (figure 6 and 7)

RAKING SHORES

In this method, inclined members known as rakers are used to give lateral supports to walls. A raking shore consists of the following components:

  1. Rakers or inclined member
  2. Wall plate
  3. Needles
  4. Cleats
  5. Bracing
  6. Sole plate

The following points are to be kept in view for the use of the raking shores:

  1. Rakers are to be inclined in the ground atclip_image001. However the angle may be between clip_image001[1]and clip_image002.
  2. For tall buildings, the length of the raker can be reduced by introducing rider raker.
  3. Rakers should be properly braced at intervals.
  4. The size of the rakers is to be decided on the basis of anticipated thrust from the wall.
  5. The centre line of a raker and the wall should meet at floor level.
  6. Shoring may be spaced at 3 to 4.5m spacing to cover longer length of the bar.
  7. The sole plate should be properly embedded into the ground on an inclination and should be of proper section and size.
  8. Wedges should not be used on sole plates since they are likely to give way under vibrations that are likely to occur.