Fly ash is a material that is brownish in color, has a fine grain size, and is obtained from the residue of burning coal. The effect of adding fly ash on the quality of the cement produced using the test parameters LOI (Loss On Ignition), BTL (Insoluble Part) and compressive strength.
The aim of this practical work is to analyze the effect of adding fly ash on the LOI dan BTL values of cement, analyzing the effect of adding fly ash on the compressive strength value of cement in accordance with SNI 7064:2014 and analyzing the effect of cement hydration time on compressive strength. The method used is the gravimetric method and immersion test.
The research results show that the more fly ash added to the cement making process, the higher the LOI value. Meanwhile, the BTL value is getting lower. The maximum percentage of fly ash addition is 9.40%. From the graph obtained, there is an increase and decrease in the compressive strength value which is not in accordance with the theory which states that the more fly ash is added, the higher the compressive strength value. From the results of the calculations that have been carried out, it is obtained that the optimum addition of fly ash is 7%. Cement hydration time affects compressive strength. The longer the cement hydration time, the compressive strength value also increases.
Keywords: Fly ash, Loss On Ignition (LOI), Insoluble part (BTL), Compressive strength