Page 33 - GRIHA Manual Volume IV - Introduction to National Rating System
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24 Griha Manual: Volume 4
10. Fal-G stabilized mud blocks: These blocks consist of mud stabilized using Fal-G. Fal-G is made
by combining fly ash, lime, and calcined gypsum together. In this process, a fly ash and
lime mix is prepared and calcined gypsum (prepared from waste of fertilizer industry) is
added in fixed proportions. The result of this process is Fal-G. Fal-G is pozzolanic in nature
and possesses characteristics similar to cement. This can be added to mud to stabilize the
mixture and produce building blocks.
11. Fly ash/sand lime bricks: These bricks are produced as a mixture of fly ash or sand along
with lime as a binding agent. They have excellent water absorption properties and good
crushing strength. However, these bricks require autoclaving. These bricks are lighter than
conventional clay bricks, are uniform in shape and require lesser mortar, have no plaster,
and are more durable than ordinary clay bricks.
12. Clay red mudburnt bricks: Clay red mudburnt bricks are manufactured by mixing alumina
red or bauxite, which is a waste by-product of the aluminium manufacture process, with
clay. The red mud improves the aesthetic quality of the bricks by giving them a pleasant red
colour. It also improves the quality of bricks even if they are made from inferior quality mud.
13. Use in mortar: Both fly ash as well as ground granulated blast furnace slag (GGBS) can be
used as a substitute of cement in masonry mortars. Use of PPC cement during production
of mortar ensures a certain mix of fly ash or GGBS in the mortar. Additional fly ash or GGBS
can be added depending upon the strength requirements as permitted by the structural
consultant.
Initiatives taken by various government departments in India
a) Initiatives by Ministry of Environment and Forest (MoEF), Government of
India
MoEF issued notification 8.0.763(E) dated 14 September1999 containing directive for greater fly ash
utilization, some of which are as follows.
i. Within a radius of 100 km from coal- or lignite-based thermal power plants (TTP), manufacturers
of bricks/blocks/tiles would use at least 25% of ash in their product.
ii. Every construction agency engaged in the construction of buildings within a radius of 50–100
kms of TPP had to use 100% fly ash-based bricks/blocks in their construction project by the end
of August 2007. Within 50 km radius of TPP, the deadline for use of 100% fly ash-based bricks/
blocks w as end of August 2005. It is pertinent to mention here that any brick/block containing
more than 25% fly ash is designated as fly ash brick/block.
b) Bureau of Indian Standards
Several initiatives taken by the country’s standardization body, Bureau of Indian Standards (BIS),
regarding higher utilization of fly ash are given below.
Updating Indian Standard on ‘Portland Pozzolana Cement – Specification Part 1 Fly Ash based’ (IS
1489 (Part 1): 1991). In the amended form, the fly ash constituent to be used shall not be less than
15% (from earlier the 10%) and not more than 35% (from the earlier 25%) by mass of PPC.
10. Fal-G stabilized mud blocks: These blocks consist of mud stabilized using Fal-G. Fal-G is made
by combining fly ash, lime, and calcined gypsum together. In this process, a fly ash and
lime mix is prepared and calcined gypsum (prepared from waste of fertilizer industry) is
added in fixed proportions. The result of this process is Fal-G. Fal-G is pozzolanic in nature
and possesses characteristics similar to cement. This can be added to mud to stabilize the
mixture and produce building blocks.
11. Fly ash/sand lime bricks: These bricks are produced as a mixture of fly ash or sand along
with lime as a binding agent. They have excellent water absorption properties and good
crushing strength. However, these bricks require autoclaving. These bricks are lighter than
conventional clay bricks, are uniform in shape and require lesser mortar, have no plaster,
and are more durable than ordinary clay bricks.
12. Clay red mudburnt bricks: Clay red mudburnt bricks are manufactured by mixing alumina
red or bauxite, which is a waste by-product of the aluminium manufacture process, with
clay. The red mud improves the aesthetic quality of the bricks by giving them a pleasant red
colour. It also improves the quality of bricks even if they are made from inferior quality mud.
13. Use in mortar: Both fly ash as well as ground granulated blast furnace slag (GGBS) can be
used as a substitute of cement in masonry mortars. Use of PPC cement during production
of mortar ensures a certain mix of fly ash or GGBS in the mortar. Additional fly ash or GGBS
can be added depending upon the strength requirements as permitted by the structural
consultant.
Initiatives taken by various government departments in India
a) Initiatives by Ministry of Environment and Forest (MoEF), Government of
India
MoEF issued notification 8.0.763(E) dated 14 September1999 containing directive for greater fly ash
utilization, some of which are as follows.
i. Within a radius of 100 km from coal- or lignite-based thermal power plants (TTP), manufacturers
of bricks/blocks/tiles would use at least 25% of ash in their product.
ii. Every construction agency engaged in the construction of buildings within a radius of 50–100
kms of TPP had to use 100% fly ash-based bricks/blocks in their construction project by the end
of August 2007. Within 50 km radius of TPP, the deadline for use of 100% fly ash-based bricks/
blocks w as end of August 2005. It is pertinent to mention here that any brick/block containing
more than 25% fly ash is designated as fly ash brick/block.
b) Bureau of Indian Standards
Several initiatives taken by the country’s standardization body, Bureau of Indian Standards (BIS),
regarding higher utilization of fly ash are given below.
Updating Indian Standard on ‘Portland Pozzolana Cement – Specification Part 1 Fly Ash based’ (IS
1489 (Part 1): 1991). In the amended form, the fly ash constituent to be used shall not be less than
15% (from earlier the 10%) and not more than 35% (from the earlier 25%) by mass of PPC.
