Standard vs Custom Battery Packs - Decoding the Power Play
Table formwork
1. DEPARTMENT OF CONSTRUCTION MANAGEMENT
PROJECT COVER SHEET
STUDENT NAME: DC
STUDENT NUMBER: C 123
COURSE/ YEAR DT117/4
SUBJECT: Advanced Construction
Technology
PROJECT TITLE: Table Formwork (tutorial 2)
LECTURER:
FOR OFFICE USE ONLY:
DATE DUE: 24th
February 2016
DATE RECEIVED:
RECEIVED BY:
REPEAT PROJECT?
MARKS:
2. Table Formwork
In the following study researcher will focus on ‘DOKA table formwork’ which a preassembled
formwork is creating a complete bay of suspended floor slab. This system offers mobility and quick
installations within repetitive structures. Researcher found that it is
highly suitable for flat slabs and beam layouts. Table form is assembled
by linking series of falsework sections including primary beams and
props that are connected to form a complete table. Trusses are linked
by cross-bracings. Table formwork can be fitted with wheels or trolley
components allowing for movement on solid ground. The definition
given to formwork is: ‘Formwork is the use of support structures and
modules to create structures out of concrete which is poured into the
modules. Formwork can be made using modules out of steel, wood,
aluminium, or prefabricated forms.’ The supporting structure of
formwork is known as false work. (Nemati, 2005)
DOKA Formwork design and considerations
DOKA Formwork is built to ensure that the concrete is formed on the
required shape, size and position, as well as providing the specified
surface finish on the concrete which will impact the material to be used as formwork. It should be
possible to strike formwork easily and safely and without causing any damage to the concrete.
Formwork has to be designed strong enough to take the pressure or weight of the fresh concrete during
placing and compaction at bearing locations, as well as any other loads it might have to face. Weak
forms will result in distortion, excessive deflections, leaks or other failure. It is important to consider
all the safety concerns relating to access, working areas, platforms, toe boards and guardrails have to
be provided separately. (Rupasinghe, 2007)
The system requires space around the construction to fly the table after every use therefore sufficient
carnage is required for lifting the table unit with appropriate lifting plans. Movement of tables must be
controlled using appropriate castors and trolleys. Planning is required to ensure sufficient space for
assembling the units. Pre-assembly is important on city centre sites with restricted construction space.
Design loads on forms
Table forms must be designed and constructed to safely support the vertically applied dead and live
loads. The formwork will have to be designed to hold:
-Form Dead Loads – the actual weight of the forms, plus the weight of wet concrete.
-Form Live Loads – the weight of workers, equipment and material storage.
-Lateral Loads - Wet concrete is like water it exerts lateral pressure which increases with the depth of
the form. (More for the vertical formwork) (Ravishankar, 2015)
During Erection
Loads on formwork during erection can arise from: the weight of material, equipment, which may be
stacked on it prior to pour and the effects of wind which may
apply forces on the formwork and its supports. Care should
therefore be taken to avoid excessive load concentrations and
to ensure that bracing is installed as early as possible.
3. During concrete pour
Dead weight on the forms is placed. Also the
weight of workers and equipment on the platform
should be considered. At this stage, also, lateral stability should be considered. Dumping concrete on
one span of the form member may cause uplift of the form in other spans. Forms must be designed to
hold together under such conditions. (Formwork T. s., 2013)
After pouring
On multi-storey projects, it is usual for work to proceed on upper floors whilst the concrete structure
below is still gaining strength. Consideration should therefore be given to the additional loads being
imposed on the formwork.
Materials
Materials used on the formwork will determine the speed and quality of finish. (Nemati, 2005)
Material Uses
Timber Timber is the most common of the materials used for form, because it has the
advantage of being easily cut and assembled on site. Also known as traditional
formwork. Timber is graded by strength into classes. It is important to use the correct
class of timber.
Aluminium Range of proprietary beams and smaller joints made from aluminium may be used in
formwork. Aluminium is strong and light, and often you need fewer supports and ties.
Plywood Both traditional and proprietary forms use plywood for panels. The plywood should
be farmed in the largest-size panel that can be handled on site. This is the most
common formwork system in DOCA formwork
Steel Steel is made in both proprietary and purpose-made forms. Proprietary systems
usually consist of panels with steel frames, clad with either a plywood or steel facing.
A range of adjustable props, soldiers, light walling and variety of ties and accessories
is available for securing the formwork in place.
Preparation for concrete pour
Check that all the formwork is free of residue or any material that may damage the finish and spray the
formwork with release agent to make dismantling of formwork easy without damaging the finish. Check
that all repairs have been completed. Check that formwork joints have been sealed. Make sure the line,
level and plumb are correct, props and supports are in the correct locations. All safety checks such as
bracing systems, wedges are nailed, clamps are tight all bolts, jacks, are in place. Once the pour starts
the work of vibrating can cause displacement of the forms. (Formwork)
Safety
Standard health and safety features include:
-Guard rails and edge protection
-The false work units can be assembled at ground level,
minimizing work at height
-Decking with non-slip surface to be used to improve safety
-Interconnected truss members create strong and stable
working platform.
-The repetitive nature of work ensures that the site operatives
can quickly become familiar with health and safety aspects
of their job. (Ravishankar, 2015)
4. Striking
Concrete can be struck once the concrete has gained enough strength to be self-supporting, and to carry
any other loads that may be put on it. (Nemati, 2005)
Advantages of Table formwork
Main advantages of table formwork allows for fast construction for large floor layouts. It comes in fully
assembled units that can be lifted quickly into place. It offers high quality surface finish that can be
achieved with quality control used. It reduces workforce requirements on site. For project management
it is easier to plan construction activities due to the repetitive nature of the work. The formwork system
is reusable with little waste generated compared to traditional formwork. The assembled units are
intended for use throughout the duration of a project without dismantling. And Increased speed and
time efficiency on site. (Ravishankar, 2015)
Summary
Innovations have focused on on-site efficiency of production, Health
and safety, and environmental issues, moving towards increasing
efficiency. Traditional formwork for concrete construction consisted
of bespoke results requiring skilled workers. These types of
formwork often had pour safety features and gives slow rates of
construction on-site and great levels of waste. Modern formwork
systems which are modular are designed for speed and efficiency
therefor The quality of surface finish will depend on the quality of
formwork used. The most populat formwork systems in industry are
offered by propriatery systems such as ‘DOKA and PERI’ which
specialise in formwork.
