4 PRECAST CONCRETE STAIRS4. PRECAST CONCRETE STAIRS

• Most of the concrete stair arrangements are possible to produce asprecast concrete components hich can be:precast concrete components which can be:- Individual steps units- Complete flight with number of steps required

• Advantages of precast concrete units:- Better quality control of the finished product

Saving of space on site as formwork storage space and- Saving of space on site as formwork storage space andfabrication space is not required.

- Stairway enclosing shaft can be utilized for hoisting or lifting ofmaterials and equipments during the major construction periodmaterials and equipments during the major construction period.

- Can usually be positioned and fixed by semiskilled labor.- Along with the extensive experiments in formwork techniques,

the coloring of the concrete with various aggregates and thesurface treatments is possible.

- It is also possible to finish prefabricated concrete stairp pelements with timber or stone.

• Limitation:Limitation:- Efficient transport and lifting vehicles are a prerequisite for the

use of industrially manufactured precast concrete elements.- Additional care is needed to achieve monolithic joints between

precast stair elements and cast in situ structural elements..

COMMON TYPES OF PRECAST STEPS UNITS:

• Rectangular cantilever steps

• Spandril cantilever stepsSpandril cantilever steps

• Sector shaped cantilever units. (Used for open riser spiral stairs.)

• TOP:I i i hIn situ concrete staircase, thestairs are supported on softpads at discrete points, a jointseparate wall and stairseparate wall and stair.

• MIDDLE:Cast-in place concrete stairshaft with prefabricated stairshaft with prefabricated stairflights, the bottom and topsupport for the flight includesound insulation, the landings

l ll d fare laterally supported on softpads, flights separated fromwall by a joint.

• BOTTOM:• BOTTOM:Staircase made completely ofprefabricated elements, theflights are extended to includeflights are extended to includethe landings, support pointswith sound insulation layer,stair is separated from walllelements.

Pictorial sequence fromthe construction site of and i i i b ildiadministration building

in Stuttgart.

VIEWS OF A PRECAST CONCRETE PRODUCTION HALL;VIEWS OF A PRECAST CONCRETE PRODUCTION HALL;1. View of reinforcement and formwork2. Prefabricated stair element being hoisted from the formwork.

1. Storage of prefabricated elementselements

2. Assembly in residential construction

3. Precast concrete element with timber element treads.t eads.