C T: Recycled Aggregate Concrete and Status in India Unit 5 Part 4

Que5.14. Explain in detail the accoutrements  which are  needed to  make ferro cement concrete. 

Answer  Following are the accoutrements   needed for making ferro cement 

1. Cement Mortar Mix  i. Its  factors are Portland cement, fine  summations, water, and   cocktails.  ii. Material should satisfy all  needful  norms  analogous to  corroborated  concrete.  ii. Complements  similar as superplasticizers, silica smothers, and fly ash can also be  used. 

2. Cadaverous  sword  To from the  shell of the structures,  sword is  frequently used in ferrocement  in the form of welded cables or a simple  slur of  sword cables, rods,  or beaches.  ii. Mesh layers are attached around this  shell  sword. The  sword also acts  as a spacer, leading to savings is the mesh subcaste.  iii. It helps in  defying tensile and punching shear. 

3. sword Mesh underpinning  sword  morass are the primary  underpinning for ferro cement.  ii. The  morass can be square woven or welded, or  funk  line  morass of  hexagonal shape and  distance  iii. In  utmost  sword  morass, whether woven or welded, the  parcels in the  longitudinal and transverse directions are different. This is also applicable  for hexagonal and expanded  morass. 

4. Fiber Reinforced Polymeric Meshes  Steel  underpinning has poor  continuity and is susceptible to  erosion.  Fiber  corroborated polymer is the stylish  volition to  sword  morass.  ii. FRP  mounts made from carbon, glass, aramid, or other highperformance  accoutrements  bedded in polymeric matrices in the form of  bars, tendons, and beaches are being produced and used these days. 

Que5.15. Explain the  colorful  styles of manufacturing of ferro  cement with their  graces and  faults. 

Answer  system of Ferro Cement Following are the  colorful construction   styles of ferro cement 

1. Cadaverous system  i. In this  system a  frame of  buttressing bars( cadaverous  sword) is  constructed, to which a subcaste of  morass is appliedFig.5.15.1. 5.15.1. Cadaverous architecture  system.  ii. Next, mortar is applied on one side and forced through the mesh until a  slight excess appears on the other side.  Advantages Following are the advantages of the cadaverous architecture   system  No elaborate form material  needed.  ii. Easy to patch up(  form) the whole area from both sides.  iii. Good penetration.  iv. Easy to repair when damaged. 

Disadvantages Following are the disadvantages of the cadaverous  architecture  system  operation of mortar from one side may be  delicate for a thick mesh  system  ii. Galvanic  erosion may develop between the mesh and cadaverous  sword  iii. Embedment of cadaverous  underpinning near the centre of the section  leads to reduced performance in bending 

2. Closed Mould Method  i. In this  system, several mesh or mesh- and- rod combination are held  together in position against the  face of a mould(Fig.5.15.2).  ii. Mortar is  also applied from the open side. The mould either remains a   endless part of the structure or can be removed and reused.  iii. In this  system, a thin subcaste of mortar is placed first and allowed to settle,  over which the mesh is placed and the alternate subcaste of mortar poured.  This procedure is repeated until the  needed number of subcaste are placed. 5.15.2. Closed mould  system.  Mortar from the side  Impermable mould  Bond swell  at interface  Advantages Following are the advantages of the unrestricted mould  system  Ideal for  plant  product since the exercise of moulds is permitted.  ii. Cadaverous  underpinning not  needed.  iii. Suitable for patented lay-up  system. 

Disadvantages Following are the disadvantages of the unrestricted mould   system  delicate to avoid internal voids, especially below  underpinning mesh.  ii. Complete penetration of mortar from one side may not be possible. 

3. Integral Mould Method  i. This  system involves asemi-rigid  frame,Fig.5.15.3. An integral  mould may be formed using froth material  similar as polystyrene or  polyurethane as the core.  ii. Mortar is poured from both sides of the mould. The mould is left inside  the ferro cement itself. This  system is ideal for field operation. 5.15.3. Integral mould  system.  Mould to remain inside  Mortar  Mortar  Advantages Following are the advantages of the integral mould   system  Provides good  severity.  ii. Provides good water-  miserliness.  iii. Provides thermal  sequestration.  Disadvantages Following are the disadvantages of the integral mould   system  Special detailing is  needed for acceptable shear connections between  rigid ferro cement layers, especially across  separating cores.  ii. Both the sides need to be finished. 

4. Open Mould Method  i. The open mould  system is a traditional  system used for boat  structure.  ii. The open mould is made of chassis wood or some other suitable material  and  strengthened by  caricatures.  iii. The mortar is applied through one side only.  iv. To  grease mould  junking, the mould is covered with a release agent  or entirely covered with polyethylene  wastes.Fig.5.15.4 illustrated the  open mould  system.  Advantages Following are the advantages of the open mould  system  No cadaverous  underpinning is  needed.  ii. More control of  homestretches than the unrestricted mould  system.  iii. Moulds can be reused.  Disadvantages Following are the disadvantages of the open mould   system  Framing and shoring system is  expensive.  ii. Complete penetration from one side isn’t guaranteed.  iii. Amenable for any shape. 

Que5.16. Explain the  geste of ferro cement under pressure. 

Answer  geste of Ferro Cement in Tension 

1. The typical  cargo  extension  wind for  corroborated concrete prism and  ferro cement prism is shown inFig.5.16.1( a) and( b), independently. 

2. The  geste is  substantially divided into three main stages  Stage I Corresponds to the  thrusting direct elastic portion of the   wind( OA).  ii. Stage II Corresponds to the unstable portion( AB) where cracking   thresholds and stabilizes.  iii. Stage III Where is  cargo  extension is  nearly direct elastic and the  crack  range increase with an increase in applied  cargo because of cracking.  This stage exists until the  buttressing  sword yields. There will be only a  many wide cracks across the  sword. 

3. FromFig.5.16.1, the main difference lies in unstable stage II( AB). 

4. sluggishly adapts to the  adding   cargo by  adding  its extensibility. numerous  fine cracks form. When cracks form, the increase in crack  range is small  compared to  corroborated concrete. 

5. Crack  range in ferro cement can be one to two orders of magnitude   lower than that of  corroborated concrete. still, there are a number  of fine cracks.

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