Abstract:
The aim of the research was to know the influence of dregs usage in the mortar mixture
against quality of mortar that was produced. Dregs is one of solid wastes that was produced
from clarification on the pulp process. The use of dregs waste of the mortar mixture is
expected to reduce the solid waste problems in the pulp and paper industry. On this
research, dregs were added with 0%, 5%, 10%, 15% and 20% compared to cement weight.
The ratio between cements and sands was 1:3. The specimen was made total 90 samples, the
size of specimen is 5x5x5 cm. Preliminary test on the based materials such as sand and dregs
was attended to verify the materials characteristic that was used on the mortar process.
Then, the compressive strength, absorption, porosity, and specific gravity tests were
conducted. Average result of compressive strength evaluation at age 7 days for the usage of
dregs 0%, 5%, 10%, 15%, and 20% respectively were 14,748 MPA, 13,430 MPa, 13,216
MPa, 12,435 MPa, and 3,638 MPa. Average result of compressive strength evaluation at
age 14 days for the usage of dregs 0%, 5%, 10%, 15%, and 20% respectively were 14,918
MPa, 14,723 MPa, 14,577 MPa, 14,134 MPa, and 4,040 MPa. Average result of
compressive strength evaluation at age 28 days for the usage of dregs 0%, 5%, 10%, 15%,
and 20% respectively were 15,253 MPa, 14,945 MPa, 14,745 MPa, 14,570 MPa, and 5,437
MPa. The high compressive strength was obtained for this mortar if the absorption, porosity
are small and the high specific gravity.
