Stiffened Raft Ground Slabs and Suspended Slabs for Residential Low-Rise Constructions

1
APPLY STRUCTURAL PRINCIPLES TO RESIDENTIAL LOW-RISE
CONSTRUCTIONS
By Name
Course
Instructor
Institution
Location
Date

2
STIFFENED RAFT GROUND SLABS AND SUSPENDED SLABS
Table of Contents
Introduction................................................................................................................................2
Suspended slabs.........................................................................................................................3
Basic features of each concrete slab...........................................................................................3
The steel used as reinforcement (mesh, bars)............................................................................5
Laps in reinforcements...............................................................................................................5
CONCRETE POURING............................................................................................................6
Precautions observed during concrete pouring..........................................................................6
CONCRETE USED...................................................................................................................7
Water-cement ratio.....................................................................................................................7
EXCAVATION..........................................................................................................................8
CONCRETE CURING............................................................................................................10
Importance of concrete curing.................................................................................................11
CONCLUSION........................................................................................................................12
Task instructions:

3
 Use technical report template provided in with all technical data researched from AS2870 to be
referenced into completed Bibliography.
 Each step needs an individual image/s with appropriate heading and relevant text.
 You need to discuss things like the steel used as reinforcement (mesh, bars), the plastic products
required, the type of concrete used (strength grade, aggregate size, slump, curing process), formwork
etc...
 This assessment task covers 15% of your overall marks for this unit.
 No sharing of images or internet downloads accepted
 This Assessment Task is to be presented in a professional report format as set out in the report
template provided.

In a Word doc format (not in Pages Format) of the Assessment Task, dated with the unit code and title
and Assessment Task number.

4
Introduction
Stiffened raft slab refers to the slab which is laid on the ground and is stiffened by integral
edge beams and a grid of different internal beams. This type of a slab is also referred to as a
slab-on-ground footing. Usually the floor slab is placed at the same time as the reinforced
internal and external walls. Beams are not required where the ground is stable but more
reactive sites the beam size and quality of the reinforcements are increased to suit with the
site conditions. In most cases during the construction of the stiffened raft slab concrete is
poured on the ground with minimal reinforcements, this makes it to be economical both in
labour utilization and material use. On the uncontrolled sites the pouring of concrete can be
carried out by the aid of supports of mass concrete piles which are constructed by the use of
natural materials.
Suspended slabs
There are three common suspended slabs which are used in Australian construction industry
and they include;
1. Insitu concrete slabs
2. Composite concrete/steel slabs
3. Precast concrete slabs
The insitu concrete slab is the most commonly used suspended slab in the construction of
residential buildings. The is usually achieved through the carefully incorporation of
fabricated systems which plays a very y important role in reducing the the overall
convectional cost of framework, site activities and time time during the construction
period.