Ferrocement, Ferrocement Building Construction & Repairs, Roofing Sheets, Ferro Alloys, Electroplating, Insulating Tanks, Mumbai, India
Home    |
Profile     |
Products     |
Application    |
Enquiry     |
 
 
 

REPAIRS, REHABILITATION AND RETRO-FITTING

   
 Ferrocement structures
 Highrise buildings
 Inbuilt Ferrocement Structural Formwork
 Ferrocement scores over R.C.C.
 Ferrocement structurals score over Steel  Structurals
 Ferrocement plated RCC structures
 Horizontal And Vertical Extension Of RCC  Buildings
 Water StorageTanks Underground  Overhead  Tower
 Repairs, Rehabilitation Retrofitting
 Waterproofing
 Mini structures
 Corrosion resistance
 Earthquake resistance
 Disaster resistance
 Ferrocement - The best fire resistant
 material of construction
 Roofs
 Rainwater harvesting
 Elevation Pergola Cladding
 Vehicular bridges
 Foot bridges
 Irrigation Structures
 Swimming pools
 Ships, boats, barges, docks
 Ferrocement Furniture
REPAIRS, REHABILITATION, AND RETROFITTING BY FERROCEMENT
 •   Most effective as it is structural  treatment
 Vibration and wiremesh Reinforced
 Layers make the mortar dense and crack  resistant
 Most durable treatment even after one  and a half  decades
 Fire resistant upto 750oC for 48 hours
 Can be made to resist high temperature
 Existing room area can be extended by a  meter or  so
 Jacketing of column and beams 40-50  mm thk.
 Prevention of buckling of columns.
 Crack formation along reinforcement  even after  repairs  by other systems  shall not take place


 Research on repairs with Ferrocement  Technology  has  proved that RCC  members improve in  strength by 125%  to 300% as compared to original  undamaged condition.
Ferrocement Cantilever

 can be planned to be Longer than R.C.C.  Cantilever  because of less Self-weight and  high strength. These  Canti- levers can take  earthquakes and cyclones more  efficiently  than R.C.C.

 
 
Ferrocement Balcony
 much lighter than R.C.C.
 Best against earthquake and cyclones
 Best replacement to crashed  R.C.C.  balcony
 new balcony can be attached to entire  building
 No disturbance to the occupants
 
Weather shed Chhajja attachment with Ferrocement plates
 •   Attachment by innovative anchoring  system
 •   joint with building totally waterproof
 Integrates with building
 Brackets generally provided for  conventional  are  eliminated
REPAIRS, REHABILITATION AND RETRO-FITTING
Significance of Ferrocement repairs
After, we in India, started manufacture of concrete in years 1930’s, the negative aspect of concrete started  showing after sometime as below:-
- Deterioration due to poor workmanship, particularly high water content and corrosion of reinforcement  and R.C.C. Technology being new.
- Leakages in concrete due to rain water as well as in water retaining structures
This menace become conspicuous after construction works which became old about 20 to 30 years. We started  realizing the importance of water cement ratio that only since about 40 years before and we have become very  much conscious and now most of our engineers try their best to have Water cement ratio to the extent of its  requirement. Even then, we did not stop production of concrete with water content comparatively more. It had  been accepted that concrete is heterogeneous material and theory of reinforced concrete design is on the basis  of cracked section below neutral axis. With this acceptance, scores of water proof additives and other admixtures  contributing to the increase in strength, durability, workability and waterproof quality of concrete have come into  market. Now it is a foregone conclusion that you cannot have best quality of concrete unless admixtures are used  in its manufacture. Also many instruments for diagnosis for defective concrete such as porosity, lamination of  cement matrix with course aggregate, corrosion of reinforcement, location of corroded reinforcement, strength of  concrete etc. have come in the market in a very big way. Systematic method of inspection observations with  measurements of the defects in concrete in a qualitative and also in quantitative manner have been developed  and schemes / system of management of diagnosis analysis to maintain / to restore water proof quality and  repairs to its original strength have been developed.
All the above methods / system of water proofing, repairs and rehabilitation of structure costs lakhs of crores  of  Rupees to the nation. In order to save such expenditure, in-convenience, loss of time and energy CAN  WE NOT  PRODUCE A CONCRETE FREE OF SUCH DEFECTS?
The quality of concrete can be improved to a large extent now. We are able to produce concrete of strength M100  or even sometimes M 200 with least reason for corrosion of reinforcement. Now a days corrosion of  reinforcement is prevented by epoxy coating and galvanizing of reinforcement. Because of theory of reinforced  concrete with provision of design of cracked section, the defects are bound to develop in due course of time  which may be delayed. Prestressed concrete is the solon to a large extent with pretension structures. However  there is possible corrosion in post tension structures due to errors in proper grouting of cables. In any case  structures now should be better than before.
Concrete is heterogeneous material. It has features to loose bond with aggregate and steel reinforcement at  early stages. It can be said it is not possible for concrete structure to last for hundred years.
Now it is the time when we should think of concrete which should not crack at all and there should be no extra  water more than required for reaction with cement. And concrete should not crack at all when put under design  loads. That means we must view or think about the theory of reinforced concrete that is a structural member is  designed as cracked section cracking accepted below neutral axis. Or crack formation can be thought to be  delayed. In other words crack width and minimum depths to stop entry of corroding forces upto reinforcement.  Also the crack width should be so minute and depth should be so shallow that water be trapped in stopping it to  travel below upto the bottom of the depth or reach reinforcement surface. The effect of atmospheric pollution or  carbonation can be minimized/eliminated by use of certain admixtures in the concrete.
Ferrocement Technology is the solution
Under laboratory loads Ferrocement bends largely alongwith reinforcement without cracking.
Under further loads, several cracks do take place, width being very negligible to few microns.
Under very large loads only little wider cracks of low value less than 0.1mm take place. After this, structure will  deform greatly but no collapse can take place. However on release of loads the cracks close. The deflection  recovery has been found to be 97%. Sometimes it is said it has inbuilt property of prestress concrete to less  extent In view of this significant feature of Ferrocement it is termed to have mechanism called ‘Crack arrest  mechanism’
Corrosion of Reinforcement
The corrosion of reinforcement in Ferrocement is most insignificant. The water cement ratio is the least giving  least extra water to react with wiremesh reinforcement. There may be corrosion of brown colouring with  wiremesh reinforcements which is not strong enough to burst cement matrix. In view of evenly spread wiremesh  reinforcement, the corrosion is the most negligible and can be said to be not at all causing any damage. We can  say the minute corrosion is dormant in the case of Ferrocement. This is the feature of Ferrocement unless it is  manufactured with inferior materials and inferior workmanship in slipshod manner. In view of this and cement  matrix being of superior quality, spalling / splitting will not take place.
We have been practicing Ferrocement Technology since more than 25 years by now. In our Ferrocement  products, we maintain water cement ratio to be 0.35 to 0.4. We invariably vibrate our Ferrocement products  either on machinery set up under controlled conditions or in- situ. In all our products to make it dense, we use  admixtures to produce maximum strength and add many positive aspects to the materials. We use non- metallic  fibers in the top of finished matrix. In view of such method of manufacture, we do not find any deterioration of  our product and no problem so far as water proof quality of Ferrocement is concerned. In our Ferrocement  products, there is no carbonation phenomena. We claim our method of manufacture is most meticulous with high  quality and superior materials and workmanship. We are confident that our structures are bound to perform in a  far superior manner.
 
Historically Ferrocement has proved to be durable and without corrosion as below:-
- A small Ferrocement boat constructed in 1887 was in operational condition till 1968 after which it was shifted to    lounge of the Vereniging Nederlands Cement industries’ office in Amsterdam.
- Several structures constructed by Mr. Pier Luigi Nervi during early 1940’s in number of cities in Italy have    been reported to be in good condition.
- During 9th International Symposium, Prof. Khan A.M. in a joint paper alongwith Prof. Rafeeqi S.F.A. and
- During 9th International Symposium, Prof. Khan A.M. in a joint paper alongwith Prof. Rafeeqi S.F.A. and    Prof.    Lodi S.H. from Karachi, Pakistan presented a paper “Performance of Park Structure made by    Ferrocement”.    They carried out experiment to study condition of a water storage tanks from the point of    view of durability    and corrosion constructed by students of Engineering college in about 1993. He has    concluded that the water    tank structure made up of Ferrocement material has sustained the atmospheric    condition satisfactorily. No    significant corrosion effect of wiremesh was visible.
In our experience with Ferrocement Technology at international level having attended all the Nine International  Symposiums we have not come across any structure that has collapsed or is damaged due to corrosion.
 
As a matter of fact, United Nations Industrial Development Organisation (UNIDO) have published a book in 1972  ‘Ferrocement boats’ and recommended the use of Ferrocement Technology at the earliest.
 
Food and Agricultural Organisation (FAO) of UNO (United Nations Organisation) organized international  conference, Ferrocement fishing boats in the year 1972. It has recommended adopting Ferrocement Technology  for fishing vessels in view of Ferrocement being a sound technology.
 
Similarly, Royal Institute of Naval Architecture (RINA, UK) and National academy of Sciences of USA have  recommended in about 1972 use of Ferrocement technology as early and as fast as possible.
 
For the present international Ferrocement society, Bangkok, founded in 1991 and Committee 549 of USA and  certain publications by RILEM, Paris, have been guiding by publishing documents for the design and construction  of Ferrocement structures.
REPAIRS
  Ferrocement Repairs And Rehabilitation Visa-vis Polymers/Guniting Repairs And Rehabilitation
Sr.
No
.
Ferrocement Repairs and Rehabilitation System Polymers/Guniting Repairs and Rehabilitation Treatment
1  Ferrocement repairs and rehabilitation system can  increase strength of columns, beams, and slabs by  30% to  15% or even more.  Polymer/guniting repairs and rehabilitation system  cannot  contribute to increase in strength of  structures.
2  Ferrocement repairs and rehabilitation system  contributes  to prevention of cracks formation.  Polymer/guniting repairs and rehabilitation  treatment  can  contribute little bit to prevention of  cracks  formation.
3  Ferrocement repairs and rehabilitation system  material  does not allow penetration of water, atmospheric gases  etc.
 Polymer/guniting repairs and rehabilitation  treatment  material can prevent little bit entry of  water and  atmospheric gases in due course of  time.
4  Ferrocement repairs and rehabilitation treatment  resist fire up to 750oC and higher for long period of  48 hours and more.  Polymer treatment looses strength heavily at about  50-60oC and guniting at about 200oC.
5  Ferrocement repairs and rehabilitation treatment is  waterproof
 Polymer/guniting repairs and rehabilitation  treatment is not waterproof.
6  Ferrocement chhajas can totally replace deteriorated  crashed RCC chhajas with dead load reduction. Even  where there is no RCC chhaja- new ferrocement  chhaja can be attached to building.  Polymer/ guniting system can not replace crashed/  collapse RCC chhaja. New RCC chhaja can not be  attached to building. At the most new weather shed  with A.C. sheet/ FRP/GI sheet can be attached but  no assured waterproof at the junction.
7  Jacketing of columns, beams, with ferrocement is  about 30mm thick and adds strength.  Jacketing of columns, beams, is 7.5cm thick,  occupying large space; may/may not add strength.
8  Ferrocement repairs and rehabilitation system is  assured and guaranteed.
 Polymer/ guniting is generally not assured and  guaranteed treatment.
9  Ferrocement repairs and rehabilitation can  conveniently repair RCC sagging slab with dead load  reduction.  RCC sagging deteriorated slab repairs is  cumbersome, time consuming and costly
10  Crashed RCC balcony can be totally replaced by  ferrocement balcony with ferrocement chhajas,  without disturbance to occupants inside. This balcony  can have drop on sides with dead load reduction.
 Crashed RCC balcony repairs by RCC balcony is  cumbersome costly and disturbance to occupants  inside. Some times balcony provision is cancelled.
11  Ferrocement Repairs and rehabilitation treatment is  highly reinforced with small dia wire mesh two layers  at least with unreinforced matrix size  6.00x6.00x1.5mm with low water cement ratio of  around 0.4  Polymer treatment is without reinforcement.  Guniting is reinforced with weld wire mesh generally  10g and even 75x75mm single layer only, thickness  40mm or so. Polymer treatment generate cracks  along reinforcement in due course of time
12  Ferrocement finish surface is smooth/sand faced  Inevitable rough surface of guniting require sand  face/smooth plaster. Thus extra expenditure.
 
Repairs/ (Replacement) of (Crashed) RCC Chajja, Balconies with Ferrocement Technology
 - RCC chhajas is of a building show sign of deterioration after 15-20years or some times early.

 - Initially, there is cracking of plaster, peeling of cover of concrete and beginning of corrosion of steel    reinforcements.

 - If condition as above is not attended, after certain few years spalling of concrete takes place on increased    corrosion of reinforcement. The chhaja will loose its life.
 - On this development normally chhaja is dismantled, and reinforcement is cut off and chhaja provision is    cancelled.
 A. Some times at this location another chhaja of (a) A.C. Sheet, (b) Aluminum, (c) G.I. Sheet, (d) FRP all with  wood/ M.S. angel brackets and frame work is provided. Such chhaja has limited life. They are not waterproof at  joint and, cause deterioration of concrete and corrosion of reinforcement of adjacent beams/lintels of building.
 B. In this location it is possible to provide a ferrocement chhajas much superior to A.C. sheet, Aluminium, G.I.  sheet and FRP.
 (i) Ferrocement chhajas is stronger than RCC and much stronger than Aluminum, G.I., FRP
 (ii) The thickness of ferrocement chhajas is 25-30mm.
 (iii) It is attached to the building by our anchoring system.
 (iv) The chhajas is totally waterproof and junction with building taken special cares to make waterproof.
 (v) No repeat waterproofing treatment is required.
 (vi) There is considerable dead load reduction.
 (vii) Ferrocement chhajas shall last several decades.
 - For some building where RCC balconies collapse due to corrosion and deterioration of concrete, ferrocement    balcony is the best solution. Simultaneously there will be dead load reduction and no disturbance and    dismantling  to inside of room.
 - It is best to provide ferrocement chhaja, lintels, balcony right at the time of building construction. Ferrocement    cantilever balcony being less in weight by about 70%, damaging effect by earthquake is the least.
 
 FERROCEMENT – Repair & Rehabilitation
 We carry out inspection study and suggest our own rehabilitation methods and systems, which are far  superior  to the conventional, as generally described below.
 Ferrocement protective anti-corrosive crack resistant membrane treatment is far superior to guniting because  we use wire mesh layers with small dia wires, say 22 g at spacing of about 12 mm center to center and high  quality vibrated cement matrix with reactive chemical coatings and finally finished smooth with the surface  with  the same finish as plaster.
 Another advantage of ferrocement is that this treatment can be carried out in patches such as junction of  beams,  columns, slabs, bottom of beams, middle portions of beams soffit of slabs, etc., In the case of  guniting this is not  possible from the practical point of view and perhaps if attempted, the cost will be  prohibitive. The finished  surface of guniting is rough and particularly in the areas within the building premises  another coat of plaster has  to be applied, whereas this is not the case in ferrocement. In such case the cost of  the work shall come down.
 In the case of epoxy and chemical rehabilitation treatment the surface are required to be highly dust-proof which  is generally not possible in repairs and rehabilitation works. Therefore, adhesion may not be as strong as  required.
 Secondly epoxy and chemical treated system cannot take large compression, shear and structural stresses. It is  found after certain period the members treated with such methods do develop cracks. The epoxy treatment loses  strength in case of fire at very low temperature, i.e. about 50 degrees C.
 Therefore, in the long run the structure will start again deteriorating. These types of treatments are non-family  material treatment and therefore at some stage or other are likely to be detached. Whereas ferrocement is the  same family material as the RCC on which the rehabilitation is required to be carried out and ferrocement is far  better in comparison as described further.
 
Ferrocement weather shed Vis-à-vis Aluminium/G.I. /A.C. sheet/FRP Weather shed
Sr.
No
.
Ferrocement Weather Shed of Balcony Aluminium/G.I./A.C. sheet/FRP weather shed of balcony
1  Junction of Ferrocement weather shed with beams/  Lintels/pardi is perfectly waterproof.

 The Junction of Aluminium/G.I./A.C. sheet/FRP  weather shed is finished with cement mortar vata.  This will crack after 4-5 years and required to be  redone. In any case there will be leakages of water  inside the flat.In due course concrete of lintels  /beams /pardi will spall and reinforcement will  corrode.

2  Ferrocement weather shed is connected to lintel,  beams, pardi by anchoring and strape connection At  the most cantilever anchor beams are provided in  case 1.5 -2mtr cantilevers.  There is no anchoring system in case of  Aluminium/G.I./A.C. sheet/FRP weather shed. The
 weather shed is supported on wood/ M.S. frame and  brackets.
3  It is very elegant- looks part of the structure.  It looks dissimilar- much below standard and shall  look ugly in comparison.
4  In this weather shed no maintenance is required.  Has to be repaired after 5-7 years.
5  Ferrocement weather shed is life time provision.  Has to be replaced after 10-12 years.
6  Dust collection will be there but acceptable.  Dust collection on FRP weather shed looks very bad  from below.
7  There is no corrosion phenomenon.  Aluminium/G.I. sheet weather shed and M.S.  brackets will corrode although painted.
8  Ferrocement weather shed is stronger than  Aluminium/G.I./A.C. sheet/FRP weather shed.  Aluminium/G.I./A.C. sheet/FRP weather shed is  much weaker than ferrocement.
9  Ferrocement weather shed is a guaranteed work  Aluminium/G.I./A.C. sheet/FRP weather shed is not  a guaranteed work.
 
Ferrocement Repairs & Rehabilitation Chhajja Attachments
 Crashed  Balcony  Old deteriorated leaking  weather shed over balcony  replaced with new  ferrocement  waterproof  weather shed with  assured  waterproofing at  junction,  for Co-Op- Hsg.  Society at  Vidyavihar.
       
 Closed view of  new  Ferrocement  Balcony With roof  drop  pardi And  weather  Shed
Ferrmocement Chajja   Attachment to the   bungalows.
       
 Over all view of  new set Of  ferrocement  Balconies From  Gr. To 4th floor  Ferrocement Chajja  attachment to the window  showing load bearing
       
 Old RCC chhajas  125mm thick  replaced with  new ferrocement  Repairs to thin  deteriorated RCC fins.  Repairs done with method  of wrapping of wire mesh  layers and high quality  vibrated cement matrix.
     
Ferrocement Chajja Attachment to the windows of the bungalows.
 
Ferrocement Repairs & Rehabilitation
 A ferrocement water tank could efficiently take onslaught of falling coconut tree with nominal damage in view of  high- energy absorbing capacity. The repair cost was a fraction of cost of the tank, which would require total replacement  of  it was plastic or steel tank.
 Ferrocement Chajjas to cover windows missed originally.
Ferrocement Chajjas
to a multi-storey
Horizontal extension of a room upto 1.5 Mtrs.
 
Balconies and Chhajja Attachments
 
 
Ferrocement structures | Highrise buildings | Inbuilt Ferrocement Structural Formwork | Ferrocement scores over R.C.C. | Ferrocement structurals score over Steel Structurals | Ferrocement plated RCC structures | Horizontal And Vertical Extension Of RCC  Buildings | Water Storage Tanks, Underground, Overhead, Tower | Repairs, Rehabilitation Retrofitting | Waterproofing | Mini structures | Corrosion resistance | Earthquake resistance | Disaster resistance | Roofing | Rainwater Harvesting | Elevation Pergola Cladding | Vehicular bridges | Foot bridges | Irrigation Structures | Swimming pools | Ships, boats, barges, docks
  Home - Profile - Products - Enquiry - Contact Us
Designed & Hosted by : MID Promoted by : GID