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Industrial High Tolerance
Floors
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High Tolerance Concrete
Execution
Concrete floors should be laid under a cover of a roof in order to gain high
quality & accuracy specially for production areas & storage areas.
Casting & finishing in the open air may affect the shrinkage of the floor
structure causing cracking & delimitation in addition to the risk of
running the concrete surface by direct sun and/or rain.
1. Sub-grade & Sub-base:
Good construction of a concrete floor begins with a well- prepared
sub-grade.Compacted granular soil sub-base is ideal for floor construction
(Standard Proctor Test 95% minimum value).It is not recommended to cast floor
slabs on plain concrete due to the risk of random early cracks because of
bonding and different movements between old & newly laid concrete.
Variations in levels of sub-base should not exceed 10mm.
2. Side Forms:
Side forms are fixed & leveled in position according to design to fit with
the Long-Strip method of construction rather than the Chequer-Board Method
which have been proved to make many problems in factories that have been
operating due to the large no. & dimensions of the floor joints.
3. Water Proofing Slip Membrane:
This membrane should be used below the floor slab to secure slab movements
without cracking and to prevent, hydration water from escaping to granular
sub-base.
4. Floor Joints:
A good floor depends on its joints working as designed in addition to bringing
their number to a minimum. Our flooring construction system is well recognized
to be as if "Joint-less" this is due to our minimizing of joints in
addition to the greatest care taken to insure perfect joint construction.
Joints as described below are according to the designer/consultant
recommendations as per included in the tender docoments.
Kinds of Joints:
a) Longitudinal or Construction Joints
These are the joints between the bays which were the positions of form
construction. They are spaced according to racking system layout and/or
machines layout Dowel or tie bars are inserted through our form construction to
insure bonding between bays & also to secure settlement at bays edges. In
some position where there is a doubt of settlement, a Tongue and Groove
construction may be used.
b) Transverse Contraction Joints (Stress Release Joints):
These joints are formed by saw-cutting with a concrete diamond blade after
concrete setting within 72hours.They are to be spaced according to design of
the whole floor slabs by a spacing from 6-9m.These joints are of width
3-5mm.Their depth is made according to the whole floor slab depth e.g. 1"
is enough for a slab 20cm. These joints are to be filled later on by an
adequate joint sealant (min. after 28 days).
c) Isolation Joints:
These joints are constructed to insure full freedom of the whole floor slab
& to neglect the effect of floor slab movements on the whole structure.
They are constructed usually around Walls & Columns by fixing impregnated
compressible board vertically against wall or base surface over full slab
depth.
d) Expansion Joints:
Expansion joints are not normally required in floors constructed under cover of
a roof unless they are very large.i.e., Floor Dimensions are more than 70m
long. If any, they will have certain construction according to details & to
be filled by an adequate joint sealant.It is recommended by the designer to
place an expansion joint every 36.00m with dowel de-bonded bars, cut &
chamfered according to specifications.
atural non metallic base origine or metallic origine in order to increase the
resistance of the surface to abrasion & indeed increasing the durability
& the non dusting proporties of the concrete floor surface with time.
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