Recently, carbon dioxide emissions have increased in succession
according to the development of industry. Additionally, the
manufacturing process of cement, which is one of construction
materials, is increasing carbon dioxide emissions. It is predicted that
the amount of carbon dioxide produced will be 10 % in the world.
As a way to solve the problem, reducing the amount of cement and replacing cement with its industral by-products such as blast
furnace slag, fly Ash, and red mud. Nonetheless, these researches
are not yet advanced in korea.
Thus, the purpose of this study is to analyze the strength
properties of geopolymer concrete with red mud. Also, The basic
performance test of geopolymer concrete such as air contents, slump,
and compressive strength will be carried out in this study.
The results of experimentation are as follow;
1) From the result of measuring air content and slump, In case
of OPC of excluding red mud represented 5.0 % and 100 mm. On
the other hand, in the case of the geopolymer concrete containing
red mud decreased as the increase of the replacement rate of red
mud.
2) The compressive strength and tensile strength of blast
furnace slag containing 10 % of red mud was the highest and was
appeared 59.06 and 4.92 MPa in the age of 56 days. The reason is
that the blast furnace slag is to promote the long-term strength
material in hydraulic potential effect. Also, All mixes were satisfied
compressive strength higher than OPC.
3) With the compressive strength, the tensile strength of blast
furnace slag containing 10 % of red-mud was the highest and
appeared 4.92 MPa in the age of 56 days. Also, the geopolymer concrete containing alkali activator showed the advanced compressive
strength development and the improved strength in early age. The
strength of geopolymer concrete was decreased when it contains 20
% of red mud too.
4) With the results of observing microstructure, geopolymer
concrete with alkali activators occured polymerization reaction rapidly
higher than OPC. Also, geopolymer reaction product which is
generated by the polymerization reaction was analyzed through
X.R.D and E.D.X experiment.
5) As the result of measuring micro-structure, a change of
micro-structure reduced on pore and minute cracks when red mud
replaces 10 % on S.E.M analysis.
As mentioned above, geopolymer concrete containing 10 % of red
mud in all mixes was the highest. Also, geopolymerization reaction
as alkali activators has occurred quickly to improved strength in
early age. Further more, the results of chemical analysis, which is
development of strength detected ions(Si4+, Al3+, and Ca2+, etc)
From now on, the researches for the durability of geopolymer
concrete containing red mud and another pozzolanic admixture and
applying the variable replacement ratio are required. In addition, The
research for the special concrete using red mud is required.