What is Stub Strengthening?
Stub strengthening is nothing but a process of rectification of corroded tower stubs by using efficient chemical compound. Strengthening of stubs is done to avoid possibility of tower collapsing and ensures long and healthy life for the tower lines.
We are very proud to state that this stub strengthening process is tested by Ramelex Group at the Govt. College of Engineering, Pune for tensile test and the stub has withstood tension beyond 701 KN that is equal to 71.5 Tons, which is more than double the capacity of the original stub.
How Stub Strengthening is done?
- The first step for Stub Strengthening is to clean area around the tower leg. Area of one meter wide and one meter deep is excavated around the leg so as to make a room for the process.
- Chimney concrete of the tower stub is broken by vibro hammer
- The rusted portion of the stub is thoroughly cleaned using power tools.
- Phosphating is done to avoid corrosion. This helps to get perfect etching.
- Two nos M.S. angle of the same size as the stub, which are pre-treated in the factory for anti-rusting and notching is done for perfect fitting. The angles are welded with specialized welding procedure.
- The welded surfaces are thoroughly cleaned by MRF cleaning agent and protected from rusting by applying special MRF anticorrosive solution.
- Anti-corrosive, low viscosity epoxy resin is filled up in the cavity in between old and new stub angles.
- Then after the whole joint is sealed by specialized MRF putty to make the surface plain and leak proof and MRF special paint is applied.
- Joint is wrapped with glass wool, fiber mesh clothing giving extra protection to the stub. In re-concreting process homogeneous jointing of old and new concrete, special bonding agent which is a specific epoxy adhesive is applied over the surface of the old concrete before final concreting is started.
- Advanced machines like needle vibrator for re-concreting process are used In the concrete special fiber mesh fiber is mixed which gets uniformly dispersed in the concrete as millions of fibers in every cubic meter.
- For better stub strengthening ang to achieve perfect waterproofing of newly cast sub concrete, special 100 per cent MRF PU paint is applied.
- The concrete is cured by using a curing catalyst for avoiding excess watering. The concrete portion and the tower legs are painted
- And finally the remaining pit portion around the concrete is backfilled with soil by compacting the layers.
- Thus finally a strong waterproof and anti-rust structure is developed for the tower stub which avoids possibility of tower collapsing due to corroded stub and ensures long and healthy life for the tower lines.
Reasons of Deterioration of stubs
- Wet, marshy soil around tower stubs due to rain & drain water.
- Watering to crops.
- Piling of garbage, soil etc. around the tower leg.
- Chemical reaction due to fertilizers and chemicals, used in the farms as well as industrial waste, etc.
- Rusting of GI earthing strip wherever embedded in chimney.
- Volumetric expansion of concrete due to hair cracks.
- Formation of cracks in concrete due to vibration of tower by wind pressure, loose nut bolts, corona discharge etc.
- Saline weather in sea shore area.
- Ageing of tower foundation.
Benefits of Stub Strengthening
- Stub life cycle increases.
- Stub Strengthening reduces the chances of tower collapse.
- Power reliability increases.
- Cost for failure maintenance reduces.