Filler slab

1. ROOFING WITH FILLER SLAB

2. RC Filler Slab The slab filled with lighter filler materials is known as the filler slab. LIGHTWEIGHT, INEXPENSIVE MATERIALS such as lowgrade Mangalore tiles, bricks, coconut shells, glass bottles, etc. are used as filler materials in filler slabs to replace the redundant concrete in tension zones. Filler slabs are one such cost effective roofing system

3. Concrete is very good in compression while it is weak in tension. Hence the steel reinforcement is placed in the tension zone. The concrete in this portion is only for holding together the steel reinforcement and has no structural purpose. THE NEUTRAL AXIS In a simply supported RCC slab The upper part of the slab is subjected to compressive forces The lower part of the slab experience Tensile forces

4. Reduces the cost of the slab by around 25-30% Creates interesting designs and patterns on the ceiling Helps in better thermal insulation of the slab due to the air pockets present.  Reduces the load on the foundation

5. The grids of steel reinforcement rods (6mm or 8mm dia.), and concreting is done over them. The concrete mix used is 1:2:4. The grid size depends upon the design, span, and the material used. For Mangalore tiles (size 23cm by 40cm), the grid size is 33cm by50cm. The filler slab can be designed like a conventional RCC slab as per IS 456-2000 design guidelines, The thickness of filler material should not exceed the depth of the neutral axis. Generally speaking, for a slab thickness of 125mm, the filler material depth should not exceed 60mm.

6. FILLERS RE-BARS SERVICE LINES

7. This 'un-productive' concrete can be replaced by a 'Filler' material which will reduce the weight of the slab and also reduce the cost by reducing the amount of concrete used. This technique saves energy-consuming concrete. Roofs and intermediate floors account for 20-25% of the total cost of the house. This roofing costs 30-35% less than conventionally used concrete roofing. Thus a considerable amount is saved in terms of materials, energy, and cost.

8. The filler material to be used must be waste materials which are available locally and lighter than concrete . Filler materials water absorption should be checked for as it will soak the hydration water from concrete. The shuttering for slab is erected as for a conventional RCC slab. 3. A minimum bottom cover of 15 mm is kept after erecting the shuttering which forms a grid and filler material can be placed centrally in each space of the grid. No filler material is provided in bands of concrete along the edge of the slab. The width of these concrete bands is normally minimum 300 mm. The reinforcement spacing in these bands is smaller than spacing around the filler materials. After all the filler materials have been placed any concealed electrical work etc., should be placed in the spaces between the filler material and then concrete is placed between the filler materials and top of it to achieve slab thickness. Concrete vibrators must be avoided in bottom portion of slab as they may disturb the placement of the filler materials. Manual tamping is advised. Reinforcement layout for a filler slab using compressed earth blocks as filler material of size 230mm x 190mm x 50mm.

9. 1)Filler slab roofing(Tiles) Filler slabs placed on the centering structure Bar bending work on top of the filler slab Concrete being pored on top of the filler slab

10. Pots which were used as filler material Pots being filled with clay before being placed on the centering structure Concrete being pored on top of pot Bar bending work on top of the pots 2)Filler slab roofing(Pots)

11. Construction of a slab with terracota pots Nandanam Kindergarten Auroville , India

12. WALL HOUSE , AUROVILLE, Anupama Kundoo - VERNACULAR ARCHITECTURE Anupama used terracotta pots as fillers to increase the effective depth of concrete. while minimizing the volume of concrete and steel in the slabs that did require to be insulated . One of her aims was to demonstrate that structural materials can also be used as finishing materials Manav Sadhna Activity Centre Yatin Pandya Reclaimed Material « biome

13. A TYPICAL FILLER SLAB IN CENTRE FOR DEVELOPMENT STUDIES, TRIVANDRUM