Merapi Volcanic Ash as An Eco-Material of Concrete Filler

Abstract

As the prediction of increasing of 2 million ton/year of cement production in Indonesia, eco-material in concrete or the concern of environment and economical concrete material is urgently needed in order to cope with the increasing trend of using non eco-material like cement in concrete. The production of one ton of cement releases approximately one ton of CO2 into the atmosphere, so it will release about 2 million ton of CO2 into the atmosphere due to one year of cement production in Indonesia. This contributes to what is now commonly called global warming. Reducing the content of cement in concrete material and substituting a part of cement content in concrete with ecomaterial, it will indirectly reduce the air pollution due to the process of cement production. This study applies an alternative of eco-material in concrete namely Merapi volcanic ash (MVA) as a filler material that has the characteristic partly like cement to substitute a part of cement content in concrete. The cement substitution is varied as 5%, 10%, 15%, 20%, and 25%. The objective of study is to investigate the effects of Merapi volcanic ash on the compressive strength in the concrete ages of 1-28 days. For the comparison, the normal concrete without the content of Merapi volcanic ash is prepared. The study results indicated that the concrete with 5-10% Merapi volcanic ash has the compressive strength close to normal concrete.