The high cost of building construction in Indonesia is one of the main problems in
providing housing in Indonesia. This can be overcome by utilizing industrial waste
that has not been utilized, for example, by using rice husk ash from burning in the
red brick manufacturing industry. Rice husk ash waste in this study was used as a
substitute for cement in the manufacture of bricks with the aim of getting better
quality and lighter brick mass. In this study the ratio used between cement, sand,
and water is 3.75 : 1: 0.25. Variations of rice husk ash used are: 0%, 10%, and
30% which replace cement as a binder while reducing the mass of cement in making
bricks. The results of the research of 0% rice husk ash brick showed a density value
of 2.49 gr/cm3, water absorption rate 9.24%, compressive strength 4.22 MPa. The
results of the 10% rice husk ash brick test resulted in a density value of 2.38 gr/cm3,
6.36% water absorption, 5.02 MPa compressive strength, and the 30% rice husk
ash brick test resulted in a density value of 2.23 gr/cm3, water absorption rate
5.88%, compressive strength 1.94 MPa. The more rice husk ash used, the lighter
the mass of the bricks and the smaller the value of the density of the bricks and the
water absorption of the bricks. The water absorption of the bricks meets the
requirements of SNI 03-0349-1989, which is less than 25%. Variations of rice husk
ash 0% and 10% in the manufacture of bricks are categorized in Quality III
according to the provisions of SNI 03-0349-1989. The use of a variation of 10%
rice husk ash is the best mixture in making bricks which has better characteristics
than normal bricks.