Black Bitumen Impregnated Fiber Filler Board-Expanded Polystyrene Board
Bitumen Impregnated Fiber Filler Board is used to filled expansion joint, It is in form of sheet and is mainly used to form and fill expansion joints in in-situ and pre-cast concrete construction.
Bitumen impregnated fiber board is formed as per IS:1838 that is used as fillers for expansion joints. Bitumen Impregnated Fiber Filler Board is durable and water proof Board and Tamper Proof Board . Bitumen Impregnated Fiber Filler Board is compressible and possess a high degree of rebound.
General Specifications of Black Bitumen Impregnated Fiber Filler Board
|Bitumen Impregnated Cane Fibre
|Density (kg/cubic M)
|Water Proof, Tamper Proof
|4 feet x 2 feet,4 feet x 4 feet and 4feet x 7.25 feet
The dimensions of the board generally are 4 feet x 2 feet,4 feet x 4 feet and 4feet x 7.25 feet . It should, preferably be purchased in one piece, matching the dimension of the joint and prepared by cutting to size smaller pieces from larger boards at site as per the requirement of Filling.
On the exposed side , the joint is sealed with approved sealing compound to a depth of at least 25 mm after application of primer. The sealing compound (I Prefer to use Polysulfide) and the primer used should be of ISI Marked Company.
Installation of Black Bitumen Impregnated Fiber Filler Board at Expansion Joint
The concrete surface is first clean, made smooth and it should be free from dirt or loose particles. As dirt decrease the sealing compound fixing quality .
When the surface is completely dry, apply a coat of hot blow bitumen conforming to IS:702 of grade 85/25 shall be given with brush or spray. When the bitumen is still hot the pre-moulded joint filler fiber board shall be pressed against the surface and held in position till the time it get fixed .
When more than one layer of filler are specified each layer shall be made to adhere to the preceding layer with a few patches of bitumen between the two layers. After placing the filler in position, the surface of the filler against which further concreting is to be done is given a coat of bitumen.
Filling of joint sealing compound at Expansion Joint
Sealing compound shall be of Grade A conforming to IS: 1834, I prefer to use Polysulfide Compound . Bitumen shall conform to IS: 3384.
Before application of the sealing compound the sides of the joint are sprayed or brushed with bitumen primer. The primer is then allowed to dry out thoroughly for at least 24 hours and then filled with a mix of 30 % fine sand and 70 % sealing compound by weight.
Expanded Polystyrene Boards in Expansion Joint
If not want to use Bitumen Impregnated Fiber Filler Board then commercial quality of expanded polystyrene products which is used for thermal insulations may also be used as filler material in expansion joints. Polystyrene Boards thickness vary from 12 mm to 50 mm. The material will have to be purchased as per the ISI Mark. The method of installations of Polystyrene Boards are similar for fixing on cold storage walls. A coat of bitumen paint may have to be applied on the board against which concrete will be placed.
Joint Sealing Strips for construction, expansion and isolation joints
Joint sealing strips may be provided at the construction, expansion and isolation joints as a continuous manner to contain the filler material and/or to exclude passage of water or any other material into or out of the structure. The sealing strips will be either metallic like G.I., Aluminium or copper, of non-metallic like rubber or P.V.C.
Sealing strips should not have any longitudinal joint and will be procured and installed in largest practicable lengths having a minimum number of transverse joints. The material is to be procured from reputed manufacturers having proven records of satisfactory supply of joint strips of similar make and shape for the jobs.
Metal Sealing Strips for construction, expansion and isolation joints
Metal sealing strips shall be either Galvanized Iron, Aluminium Strip or Copper Strip , U shaped and Z shaped.
The transverse joints will be gas welded using brass rods and approved flux and will be tested by an approved method to establish that it is leak proof. In case it is found that the joints cannot be made leak proof, longer lap length and different method of brazing which will render it leak proof. The edges shall be neatly crimped and bent to ensure proper bond with the concrete.
a) G.I. Strips:
G.I Strips shall be minimum 1.5 mm thick and 150 mm in width unless specified otherwise. The standard of Galvanising shall be as per relevant Indian Standards for heavy duty work. The strips shall be strong, durable, without any rust or crease. At the joints, the over-lapping should be for a minimum length of 50 mm.
b) Aluminum Strips:
Aluminum strips shall be minimum 18 swg. thick and 300 mm wide unless specified other wise and shall conform to
IS:737 of 19000 grade or 31000 grade (Designation as per IS:6051). A minimum lap of 50 mm length is required at the joints.
c) Copper Strips:
The Copper strips shall be minimum 18 swg. In thickness and 300 mm width unless specified otherwise and shall conform to the relevant Indian Standards.
Strip should be cleaned properly before use to expose fresh surface, without any reduction in gauge. A minimum lap of 50 mm is length is required at the joints.
Non-metallic Sealing Strips
These will be normally in Rubber or P.V.C. Rubber or P.V.C. joint seals can be of shape having any combination of the following features :
b. Central bulb
c. Dumb-bell or flattened ends
d. Ribbed and Corrugated Wings
As these types of seals can be easily handled in very large lengths unlike metal strips, transverse joints will be allowed only under unavoidable circumstances. Engineer must match the central bulbs and the edges accurately.
a) Rubber Sealing Strips :
The minimum thickness of rubber sealing strips shall be 3 mm and the minimum width 100 mm. The material should be resistant to corrosion, abrasion and tear and also to attacks from the acids, alkalies and chemicals normally encountered in service. The physical properties will be generally as follows.
Sp. Gr. : 1.1 to 1.15
Shore Hardness : 65 A to 75 A
Tensile Strength : 25 – 30 N/mm²
Max. safe continuous
temperature : 75°C
Ultimate Elongation : Not less than 350%
b) P.V.C. Sealing Strips
The minimum thickness of P.V.C sealing strips is to be used should be of 3 mm and the minimum width 100 mm. The actual size and shape will be as shown in drawings/Schedule of Items and/or as directed by the Engineer. PVC Sealing strip to be used is of good quality Polyvinyl Chloride highly resistant to tearing, abrasion and corrosion.
The physical properties of PVC Sealing strip should be as follows.
Sp. Gr. : 1.3 to 1.35
Shore Hardness : 60 A to 80 A
Tensile Strength : 10 – 15 N/mm2
Maximum Safe Continuous
Temperature : 70 deg C
Ultimate Elongation : Not less than 275%
Measurement of Bitumen Impregnated Fiber Filler Board in Expansion Joint
Bitumen Impregnated Fiber Filler Board in expansion joint is measured in Square Meter.