Detail guidelines of RCC Staircase Design
RCC structure is built with different building elements like Footings, Columns, Beams, Slabs, Staircase etc.
These components are reinforced with steel that adds strength to the structure. Staircase is considered as one of the most vital element in a RCC structure.
Stairs: Stairs include steps which are provided in a series to give access to various floors of a building. As a stair is the only way of making communication among the different floors of a building, proper care should be taken to select the exact location of the stair.
In a residential house, the staircase should be located adjacent to the main entrance.
In a public building, the stairs should be centrally situated adjacent to the main entrance itself to give instant accessibility to the main buildings.
There should be sufficient lighting and proper ventilation to all the staircases.
Different types of Staircases:
? Straight stairs
? Dog-legged stairs
? Open newel stair
? Geometrical stair
RCC Dog-legged Staircase design: Under this type of staircase, the subsequent flights mount to opposite directions. The two flights in plan are not segregated with a well. A landing is arranged in accordance with the level at which the direction of the flight is changed.
Method for Dog-legged Staircase design - On the basis of the direction along which a stair slab span, the stairs are categorized as following two types.
Stairs spanning horizontally: The support is given each site of these stairs with walls. Stringer beams or at one side with wall or at the other side with a beam.
Loads:
? Dead load of a step = ? x T x R x 25
? Dead load of waist slab = b x t x 25
? Live load = LL (KN/m2)
? Floor finish = guess 0.5 KN/m
Stairs spanning Longitudinally - In these types of stairs, the support it provided to the beam at top and at the bottom of flights.
Loads:
? Self weight of a step = 1 x R/2 x 25
? Self weight of waist slab = 1 x t x 25
? Self weight of plan = 1 x t x 25[(R2 + T2)/T]
? Live load = LL (KN/m2)
? Floor finish = guess 0.5 KN/m
To create perfect design of an RCC stair, initially different types of loads to be enforced on the stair should be analyzed.
To find out the volume of strength necessary to bear the load, the load calculations should be perfect. The strength bearing ability of a staircase is based on the amount of steel and concrete used.
The proportion of steel to concrete should be according to the standards. Steel in the staircase will bear the tension enforced on it and the concrete bears the compression.
