Reinforced
steel in RCC increases strength of
structure when cohesive bond between
concrete and steel is achieved. Loose
corrosion reduces this cohesive bond,
which in turn reduces the strength
of the structure. Reinforcing bars
are placed in highly corrosive environment
of concrete since concrete contains
water in liquid form, salts for electrolysis
and exothermic reaction. Rebars remain
in the environment leaving behind
a highly porous structure. To prevent
/ arrest this corrosion, Z300TM
treatment may be deployed, which provides
for isolation of rebars from this
environment with negligible reduction
in cohesive bond. This has been determined
by the Pull Draw Test. It is commonly
seen that RCC structures crack because
of expansion of rebars due to corrosion
over a period of time. In order to
overcome such situation and improve
quality of the structure, Z300TM
process‘ is only the solution
available today.
Preventive
cost is a major area of concern. Z300TM
process operates on a lower cost as
compared to other protective agents.
In case of tor steel, Z300TM
costs appro. Rs.500/- per MT of steel
at site; at manufacturing stage the
cost reduces to Rs. 400/- per MT (approx.)
of steel. Other methods such as epoxy
and zinc coating would cost in excess
of Rs. 2,800/- per MT of steel. Also,
there are numerous disadvantages associated
with these methods including crack
on coating during transit to the sites
and the inability to carry out patchwork.
approximate
costing table -
| Cost
of construction (RCC) per
sq.foot : |
Rs.
350/- |
| Cost
of steel per sq.foot (@ 17%
of the cost of construction)
: |
Rs.
60/- |
| Approx.
rate of steel per MT : |
Rs.
17,000/- |
| Cost
of Z300TM
per MT of steel : |
Rs.
500/- (3% the cost of steel)
|
Any
other method employed will, on an
average, cost you Rs.16.50 per sq.
foot, which is approx. 5% of the total
cost of per sq.foot construction as
compared to the cost of Z300TM,
which is approx. 0.5 %. If painting
is to be carried out, it is advisable
to coat the metal with Z300TM
during the processing stages and at
the time of receiving of steel at
site. This will approx. cost Rs.750/-
per MT of steel used, including touch
up cost extra.
Corroded steel at many sites, today,
is a common sight, since protective
measures are not undertaken. In such
cases, the only viable option of salvaging
the rest of the metal surface area
is by means of a recovery process.
We have done one such recovery, at
a cost of Rs.1,800 per MT, for approx.
200 MT of tor steel at one site, which
was partly in the constructed state,
and partly lying as raw metal. Recovery
cost of Z300TM
process can be calculated by a treatment
dose on a sample piece, since percent
layer of corrosion on the surface
cannot be measured at remote sites.
Loss of metal, as a result of corrosion,
cannot be measured. Use of Z300TM
prevents further loss and also enables
a cleaner metal surface. Z300TM
may also be pumped into the RCC structure
using pressure. There is no loss in
the strength of the cohesive bond,
forms a layer as thin as 1 micron,
which can be removed off the surface
if required.
Today, a corrosive surface may be
concealed with red oxide paint. However,
this could lead to many problems,
which are not calculated in your standard
factor when designing (Please refer
our technical note for more details).
Welding joints & bimetallic joints
are weak areas that are susceptible
to corrosion as they are also the
links to the pain structure. The convenience
of handling (including the safety
aspect), the ease of application of
Z300TM,
and its cost-effectiveness make it
an appropriate coating agent to be
used.
USE
Z300TM
AS PER YOUR NEEDS -
·
All steel bought should be coated
to reduce primary corrosion cells
as well as control during transit
period.
· Further corrosion in steel,
already corroded, can be reduced by
simple application.
· Corrosion present at the
time of manufacturing, welding other
cavities, threads, nuts, bolts, water
pipelines, etc. can be controlled
using Z300TM.
We
would recommend that steel be stored
at plant or site on wooden batons
or planks to control the electrolysis
process and bimetallic corrosion arising
due to earthing and static charge,
which need to be isolated. This is
an ancient method that has been reintroduced
to control rate of corrosion.
For
trial purpose, Z300TM
is available in a 1 / 5 / 20 / 200
liter pack, against advance payment,
as per standard quotation form.
|
