| dc.description.abstract | The use of cement as a binder in concrete has an environmental impact, because during the
cement manufacturing process a large amount of CO2 emissions are released into the atmosphere.
To overcome the problem of pollution, cement substitutes are needed. Geopolymer concrete is an
alternative concrete that can be used to overcome the negative impacts of using cement concrete.
Geopolymer concrete uses fly ash which contains high silicates and aluminates as a substitute for
cement, because these two chemical elements can react with alkali activators and become binders.
In addition, rice husk ash is a pozzolanic material that contains high silicate but low aluminate.
The extent to which the characteristics of geopolymer concrete change with the mixing of these
materials needs to be investigated. This study aims to determine the characteristics of polymer
concrete, which include density, wave propagation velocity, compressive strength, and modulus
of elasticity with the addition of rice husk ash and viscocrete 1003.The geopolymer concrete
mixture in this laboratory experiment used a weight ratio of water to fly ash of 0.25, with a ratio
of Na2SiO3: NaOH of 4:2. The concrete precursor material used was fly ash with a proportion of
444 kg per m3 of concrete. Viscocrete 1003 was added by 0.6% of the weight of the precursor,
and rice husk ash was used as an additive material with variations of 0%, 5%, 10%, 15%, 20%
of the weight of the precursor. The results of this study indicate that geopolymer concrete with
the addition of 0% husk ash produces the highest values in the density test, compressive strength
test, and wave propagation test, while the modulus of elasticity cannot be displayed because the
compressive strength value is too small. The addition of rice husk ash to geopolymer concrete
reduces the strength of the concrete. From these variations, the highest compressive strength
value is 4.798 MPa. It can be concluded that the concrete in this study can be used for non
structural elements in buildings. | en_US |
