Types and Design of Staircases

RCC Structures are only strengthened solid structures. RCC structure is made out of building parts, for example, Footings, Columns, Beams, Slabs, Staircase and so forth. These parts are fortified with steel that offer security to the structure.

Staircase is one such significant segment in a RCC structure. In this article, we will talk about various kinds of staircases and study the dog-legged strengthened concrete solid staircase structure.

About Stairs: Stairs consist of steps orchestrated in an arrangement for motivation behind offering access to various floors of a structure. Since a stair is regularly the main method for correspondence between the different floors of a structure, the area of the stair requires great and cautious thought.

In a private house, the staircase might be given close to the fundamental passage. In an open structure, the stairs must be from the primary passageway itself and found midway, to give fast availability to the vital condos.

All staircases ought to be enough lit and appropriately ventilated.



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Published By
Rajib Dey
www.constructioncost.co
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Advantages of cross wall construction

Cross wall construction stands for a building construction method. Under this system, the precast load-bearing walls are arranged perpendicular to the lateral axis of the building.

In cross wall construction, the load-bearing walls provide support to the floors, roofs and the beams. The structures built up with the cross wall method are structurally strong and cost-effective.

Given below, the construction details and the features of cross wall construction :-

Features of Cross Wall Construction: Under cross wall construction, the prefabricated walls are arranged in series. These load-bearing walls transmit the structural loads securely to the foundation devoid of any concrete or steel frame. They also serve as shear walls and safeguard the building against lateral movement.

Cross wall construction is ideal for the buildings which contain maximum of 5 stories where all the floors come with similar plans. The intermediate floor span among the load-bearing walls offers adequate lateral control.

If both the load-bearing walls and the floors belong to precast members, then a series of boxes should be created. This type of construction is normally defined as box frame construction.

Cross Wall Construction Systems:

1. Precast materials can be sent at the right moment.
2. The precast wall components are arranged both horizontally and vertically. They are grouted and attached according to the plan through hidden joints and ties.
3. Prior to finish the complete structure, mechanical & electrical installation works, finishing works and other multifaceted works on the walls should be finished.

The cross walls are attached with any of the following key connections:

1. Wall-to-wall by Horizontal Joints
2. Wall-to-wall by vertical joints
3. Wall to the base foundation

When the cross walls are placed along the floor, the front and the rear walls can be non-load bearing claddings. The connections among the non-load bearing walls and the cross walls should be designed and built up with a proper care to avoid moisture infiltration and other issues.

Advantage of Cross Wall Construction:

1. Cross wall construction forms a long-lasting structure.
2. The initial construction cost is fewer.
3. With regard to conventional construction method, cross wall construction method save huge time and cost.
4. The building built up is structurally strong that contains greater fire and acoustic separation among the nearby rooms.
5. The construction achieves good thermal mass.
6. Site co-ordination is simple at the time of providing cross wall construction.
7. The structure ensures superior security.
8. The maintenance cost of the structure developed with cross wall construction method is fewer.
9. No scaffoldings are required for cross wall construction.
10. The structure remains monolithic with good air tightness.

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Published By
Rajib Dey
www.constructioncost.co
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Difference between Ribbed Slab and Solid Slab

Slabs are actually structural members made for floors and roofs in buildings which may be formed of solid thickness or ribbed with ribs running in one or two directions.

About Slab: Slab is a useful element which is made to create flat and useful surfaces like floors, roofs and ceilings of a building. It is a horizontal structural component with top and bottom surfaces parallel or near so. Commonly these slabs are supported by walls, beams, columns or the ground. The depth of a concrete slab floor is very small similar to its span.

These slabs may be solid of uniform thickness or ribbed with ribs running in one direction or two directions or waffles.

Ribbed Slabs: These types of slabs are slabs cast completely with a series of closely spaced joist which in turn are supported by a set of beams. The main benefit of ribbed floors is the lowering in weight achieved by removing part of concrete below the neutral axis. This creates this type of floor economical for buildings with a long span with light or moderate loads.

Solid Slabs: Solid slabs are completely customizable concrete slabs of varying width, length and thickness which can be cast with specially inserts to lift, mounting or connecting hardware. These slabs of uniform thickness can be one-way or two-way:

• One way slab: When a slab is supported on all four sides and the proportion of long span to short span is equal or may be greater than two, it is definitely one way slab. The load on this slab is carried by the short span in a direction but the main reinforced bar and distribution bar in transverse direction. Example: Verandah Slab, Cantilever Slab etc.

• Two Way slab: When a slab is supported on all four sides and the proportion of the long span to the short span is less than 2. It is considered as two way slab. The load on this slab is carried by both the short span and long span though the greater amount of load is carried by the shorter span. Example: Slab used in multistory building.

Sourcewww.dailycivil.com



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Published By
Rajib Dey
www.constructioncost.co
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How to calculate number of tiles for a floor

A tile is mainly a thin object usually square or rectangular in shape and it is a manufactured piece of hard-wearing material like ceramic, stone, metal, baked clay or even glass which is generally used for covering roofs, floors, walls or other objects like tabletops. Tiles are often used to form wall and floor coverings and can range from simple square tiles to complex or mosaics.

Floor Tiles are mainly used in Residential buildings to make every possible thing beautiful; engineers used them almost everywhere like in stairs, lobby, apartment, roof etc. Though floor tiles are used everywhere but wall tiles are mainly used in bathroom and kitchen.

So, calculating tiles for bedroom and bathroom are not similar so there are some things required to keep in mind while calculating tiles. While calculating floor tiles three things need to consider which are:

• Sometimes a special tile design is used on a floor so there the design tiles need to calculate separately and deduct the tiles quantity from the floor tiles quantity.
• Skirting is a pillage of tiles which is laid in walls and adjacent to the floor.
• Any apartment different tiles may be used in an apartment, while calculating it is need to check.

The basic of calculating floor tiles is to get the area of tiling floor, for that just needed to get the dimension of two opposite direction and multiply them.

But depending on the situation there are two different methods that can be used while calculating tiles, those are: Average method and Counting method.

Source: www.acivilengineer.com



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Published By
Rajib Dey
www.constructioncost.co
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Shoring, its types and uses

It is the construction of a short-lived structure to support provisionally an unsafe structure which supports walls laterally.

This construction process can be used when walls come out or when walls crack due to unequal settlement of foundation and repairs are to be conducted to the cracked wall or when a close structure needs bringing down or when openings are to be newly made or enlarged in a wall.

Types of Shoring:

1. Raking Shoring: in this process, the inclined members known as rakers are used to give sideways supports to walls. A raking shore has some components which are- Rakers or inclined member, Wall plate, Needles, Cleats, Bracing and Sole Plate. Here are some points to keep in mind while use of raking shores, like:

a) Rakers are to be disclosed in the ground at 45°,
b) in the tall buildings the length can be reduced by applying rider raker,
c) they should be properly braced at intervals,
d) the size is to be measured as per the anticipated thrust from the wall,
e) the centre line of a raker and the wall should meet at floor level,
f) shoring may be spaced at 3-4.5 m spacing to cover long length of the bar etc.

2. Flying Shoring: It is a system that gives supports to the party walls of the two buildings where the intermediate building is to be pulled down and rebuilt.

This shore consists of wall plates, needles, cleats, horizontal shores or struts and inclined struts in different forms that vary on situation. The wall plates are placed against the wall and secured to it.

3. Dead shoring: It is the system of shoring used to render vertical support to the walls and roofs, floors etc. when the lower part of a wall has been removed to provide an opening in the wall or to rebuild a defective load bearing wall in a structure.

This shore consists of an arrangement of beams and posts which need to support the weight of the structure above and transfer same to the ground on firm foundation below. The shores stand away from wall on either side to allow working space while the needles are props are in position.

Article Source: theconstructor.org



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Rajib Dey
www.constructioncost.co
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Variations among Load bearing and framed structures

Superstructure is the section that situates over the ground. It comprises of walls, columns, beams, floors, roofs, doors, windows, lintels, staircases.

Types of super structures on the basis of load transmission

The super structures are categorized as follow :-

a. Load bearing structures
b. Framed structures

Load bearing structures:

Under this type of structure, the load on the structure is delivered in vertical direction through walls and then the wall transmits these loads and the self weight. These types of constructions are mostly found in residential buildings where the dimension of rooms is fewer. The residential buildings up to ground + 2 floors is constructed inexpensively with such structures.

Framed structures:

Under this type of structures, a frame work of columns and floors are constructed initially. Then the walls are erected to divide the living area.

The walls are dependent on self weight only. These types of structures are suitable when there are lots of stories in a building as well as when bigger areas should be covered free from walls.

Variations among load bearing and framed structures

Load bearing structure:

1. Construction cost is minimum
2. Best fit up to three stories
3. Walls are thicker and consequently floor area is curtailed.
4. Construction process is slow.
5. Once the construction is completed, it becomes difficult to modify the position of walls.

Frame structure:

1. The construction cost is higher
2. Ideal for different number of stories
3. Walls are thinner and as a result, more floor area can be utilized.
4. Rapid construction speed
5. If required, the location of wall may be modified.
6. Resistance to earthquake forces is good



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Published By
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www.constructioncost.co
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