Home Posts RSS Comments RSS Search

Sizing of the Slab.

Twittear 0 0

0Me gusta

In general floor slabs are designed by

eye from experience and are made up of

a sub-base layer of hardcore blinded

with either sand or concrete and sealed

with a slip membrane upon which the

slab is cast. However, an alternative

approach is to consider the make-up and

performance requirements in more

detail.

Floor slabs supported directly on the

ground are subject to bending and shear

forces resulting from differential

movements in the ground support

during loading. In addition they are

subjected to thermal and moisture movements which can produce the critical stresses

particularly in slabs on uniform support.

Typical reinforcement proportions of 0.1–0.25% will not significantly affect the crack

width and distribution. Limiting crack width to say 0.3 mm would require significant

amounts of reinforcement of the order of 0.4%. Current thinking is to saw the slab into

panels approximately 6 m square, the thermal contraction and drying shrinkage cracks

being induced by the saw cuts. The use of square mesh ‘A’-type fabrics is now more

common than ‘B’-type fabrics and the ‘small panel’ approach is considered to result in

lower risk of cracking than the use of heavy fabric and more widely spaced joints.

The design process therefore should be to calculate the rein- forcement required for

ground support, and then decide on sawn or formed joint locations to minimise the

thermal and shrinkage stresses in the panels. The analysis for ground support can be

assessed by the adoption of a design based upon spanning or cantilevering over a

depression similar to that adopted for crust rafts. Due to the relatively small loads

applied to slabs, the likely settlement depressions tend to be of small diameter when

compared with a similar crust raft condition (see Table 11.3).

Table 11.3 Ground floor slabs – typical assumed depressions

Total Pageviews 121,033

Feed

Enter your email address:

Subscribe

Delivered by FeedBurner

Search

Search

Follow @Engineershrb

Builder's Engineer

Categories: SLABS

Related Post:SLABS

0 comentarios:

Post a Comment

Нађи нас на Фејсбуку

Engineers

474 people like Engineers.

Фејсбу ков дру штвени додатак

Свиђа ми се

LabelsFOUNDATIONS (134) PILES (61)

WATERPROOFING (58) SOILS (47) FOOTINGS

(30) SITE EXPLORATION (30) BUILDING (28)

STRUCTURES (22) PAD FOUNDATIONS (18) STRIP

FOUNDATIONS (18) CONCRETE (15) RAFT

FOUNDATIONS (14) DRILLED PIER FOUNDATIONS (13)

RETAINING WALLS (10) EXCAVATIONS (9) SURFACE

SPREAD FOUNDATIONS (9)

Popular Posts

Design Example 3: Reinforced Strip

Foundation.

The load-bearing wall of a single-storey

building is to be supported on a wide

reinforced strip foundation. A site

investigation has revea...

Example: Pile cap design.

A pile cap is required to transfer the load

from a 400 mm × 400 mm column to four

600 mm diameter piles , as shown in Fig.

14.30 . Pile caps...

TIMBERING OF TRENCHES - SOILS.

When the depth of trench is large, or

when the sub-soil is loose, the sides of

the trench may cave in. The problem can

be solved by adopting...

COMPONENTS OF A BUILDING: Sub-structure and

Super-structure.

A building has two basic parts: (i) Substructure or

foundations, and (ii) Supers1ructure. Sub-structure or

Foundation is the lower p...

LIVE LOADS IN A BUILDING: on floors, on

roofs.

Live loads, also called as super-imposed

loads, consisi of moving or variable loads,

due to people or occupants, their

furniture, temporary ...

BORING METHODS - SITE EXPLORATION.

The following are the various boring

methods commonly used: (i) Auger boring.

(ii) Auger and shell boring. (iii) Wash

boring. (iv) Percus...

TYPES OF FOUNDATIONS: Shallow foundation, Deep

Foundations.

Design Example: Floating Slab.

Design Decisions - Floating Slabs.

Floating Slabs (Ground Slabs).

DRILLED SHAFTS (6) MAT

FOUNDATIONS (5) SHEET PILE (5) WALLS (5) SLABS (4)

SLIP CIRCLES AND UNDERPINNING (4) STEEL (3)

BULKHEADS (2) FLOOR (2) MASONRY (2) ROOF (2) STONE

(2) STRUCTURAL DESIGN (2) COLUMNS (1) DOORS (1) PIPES

(1) TIMBER (1) TIMBER PILES (1) VERTICAL TRANSPORTATION

STRUCTURES (1) WINDOWS (1) WOOD CONSTRUCTION (1)

Newer Post » « Older Post

Enter your comment...

Comment as: Google Account

Publish

Preview

Home

Foundations may be broadly classified

under two heads: (a) Shallow

Foundations (b) Deep Foundations.

According to Terzaghi, a foundat...

Grillage Foundations - Description.

Grillage foundations consist of a number

of layers of beams usually laid at right

angles to each other and used to

disperse heavy point load...

Steel Grillage Foundation - Method of

Construction.

Steel grillage foundation is constructed of

steel beams, structurally known as rolled

steel joists(RSJ.), provided in two or more

tiers. In...

Design Example 5: Pad base – axial load

plus bending moment (small eccentricity).

A column pad base is subject to an axial

load of 200 kN (dead) plus 300 kN

(imposed), and a bending moment of 40

kNm. To suit site constrai...

Powered by Blogger.

Blog Archive

▼ 2013 (155)

► December (1)

► November (4)

► October (4)

► September (5)

► August (4)

► July (5)

► June (5)

► May (8)

► April (9)

► March (17)

► February (31)

▼ January (62)

Design Example: Rectangular Balanced

Foundation.

Balanced foundations (rectangular, cantilever,

tr...

Design Example: Tied Portal Frame Base.

Tied foundations - Design.

Tied and Balanced Foundations.

Tied and Balanced Foundations.

Design - Jacking Raft

Design - Buoyancy Raft.

Design - Beam Strip Raft.

Design - Lidded Cellular Raft.

Design - Cellular Raft.

Design Example: Slip Sandwich Raft.

Design - Slip Sandwich Raft.

PIPING FAILURES IN SAND CUTS.

BRACED CUTS.

ANCHORAGE OF BULKHEADS.

Crust Raft - Design.

Design Example: Nominal Crust Raft.

Design - Nominal Crust Raft – Semi-Flexible

Semi-Fexible Rafts: Design Span for Local

Depressi...

Bearing Pressure Design - Semi-Fexible Rafts.

Design of Semi-Fexible Raft Layouts

Design Principles - Semi-Flexible Rafts.

Design Example: Floating Slab.

Sizing of the Slab.

Design Decisions - Floating Slabs.

Floating Slabs (Ground Slabs).

Sizing of the Design: Continuous Beam Strips.

Design Decisions: Continuous Beam Strips.

Rectangular and tee-beam Continuous Strips.

Design Example 5: Pad base – axial load plus

bendi...

Pad Foundations with axial Loads and Bending

Momen...

Design Example: Reinforced Pad Base.

Design Example 3: Reinforced Strip Foundation.

Design Decisions - Sizing up of the Design -

Reinf...

Reinforced Concrete Pads and Strips.

Unreinforced Concrete Strips.

Design Example: Deep Mass Concrete Pad Base.

Design Example: Trench Fill Strip Footing.

Trench Fill Foundation Design Decisions.

Trench Fill Strips.

Unreinforced Concrete Pads and Strips.

Foundations: General Design Method.

Structural Design of Foundation Members.

Foundation Design: Calculation of Applied Bearing

...

Foundation Design: Definition of Bearing

Pressures....

FOUNDATION DESIGN CALCULATION PROCEDURE.

Exploitation of Foundation Stiffness and

Resulting...

Select Foundation: Questioning the information

and...

General Approach to Choice of Foundations.

Information collection/assessment - Structural

Co...

Selection of the Appropriate Foundation.

Grillage Foundations - Description.

Retaining Walls.

Pier and Beam Foundations.

Floating Ground Foor Slabs.

Suspended Ground Floor Slabs.

Pile Caps and Ground Beams.

Anchor Blocks - Description.

Anchor Piles - Description.

Steel Piles - Description.

Timber Piles - Description.

► 2012 (304)

Builder's Engineer | Based on the Design by Tricks-Collection | Unlimited Entertainment like TV Shows and Movies collections