Effect of Fly Ash as Partial Replacement of Cement in Aggressive Environment

Abstract

Based on the Appendix I of Peraturan Pemerintah Republik
Indonesia No. 101 year of 2014 on the management of
Hazardous and Toxic waste, fly ash is categorized as
Hazardous and Toxic waste with a waste code B409. Fly ash
can be used as a cement replacement material in the
manufacture of concrete because it contains alumina and silica
which can be used as construction raw material. The cost of
making fly ash mortar is slightly more expensive than
conventional mortar. It is because of mortar fly ash uses
chemical activators. Several literature reviews show that fly ashbased
mortar having good mechanical character, power and
good performance in acidic and sulfate environments. In this
research, fly ash mortar was made using curing (treatment) that
is 24 hour and 48 hours of curing oven. In this research
simulated on aggressive environment that is 5% of H2SO4 and
10% of HCl for 0, 7, 14, and 28 days. Due to functioning as a
building construction material, it is necessary to test the loss of
compressive strength and weight loss. The test was performed
for 0, 7, 14 and 28 days with the result: 1) fly ash mortar had
loss of compressive strength and optimum weight loss at the
age of 7 days each on the 24-hour of curing oven and 48-hour
of curing oven.2) although the cost the production of fly ash
mortar in general is slightly more expensive than cement
mortar, but in terms of environmental aspects it has a significant
effect on CO2 reduction than the cement production using coal
combustion.