Fly Ash For Concrete

Fly ash is created from coal burning raw material in power plant. The price is about Rp 100 /kG. From Kompas Newspaper told that Suralaya Power Plant produce 33,000 T/month, Tanjung Jati Power Plant produce 15,000 T/month and Paiton Power Plant 43,000 T/h.

Fly ash could be add in concrate composition. It is about 20 – 30 % of concrete composition could be reduce cement, sand, stone and lime composition in concrete and the strength with add of fly ash inside is not reducing significantly.

Reducing of cement use coul be reduce CO2 emission caused by cement production produce CO2 gas which one of glass house effect. Mining of sand, stone and lime reduce as well so environmental effect could be minimize.


From the some reset, the blended of cement, stone, lime and fly ash pouring into the cylinder cast with diameter 15cm and length 20cm. It ready to test after 28 days hardening process with cost production around Rp 700,000. The result of test said not reduce significantly if we use without fly ash but total production of concrete could be reduce.

Another production likes Con-block and Paving block said, Con-block with fly ash has strength 37kg per sq-cm and normal Con-block has 38kg per sq-cm. Paving block with fly ash has strength 105,47 kg per sq-cm, and normal Paving Block has 200,3 kg per sq-cm.
The summary, additional composition of fly ash inside concrete can be reduce of strength but not significantly, but the cost of cement production and environmental effect can be reduce.

Con Block

















Paving Block